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Premise Methods Results Conclusions The use of hybrid breeding systems to increase crop yields has been the cornerstone of modern agriculture and is exemplified in the breeding and improvement of cultivated sunflower (Helianthus annuus). However, it is poorly understood what effect supporting separate breeding pools in such systems, combined with continued selection for yield, may have on leaf ecophysiology and specialized metabolite variation.We analyzed 288 lines of cultivated H. annuus to examine the genomic basis of several specialized metabolites and agronomically important traits across major heterotic groups.Heterotic group identity supports phenotypic divergences between fertility restoring and cytoplasmic male‐sterility maintainer lines in leaf ecophysiology and specialized metabolism. However, the divergence is not associated with physical linkage to nuclear genes that support current hybrid breeding practices in cultivated H. annuus. Additionally, we identified four genomic regions associated with leaf ecophysiology and specialized metabolism that colocalize with previously identified QTLs for quantitative self‐compatibility traits and with S‐protein homolog (SPH) proteins, a recently discovered family of proteins associated with self‐incompatibility and self/nonself recognition in Papaver rhoeas (common poppy) with suggested conserved downstream mechanisms among eudicots.Further work is necessary to confirm the self‐incompatibility mechanisms in cultivated H. annuus and their relationship to the integrative and polygenic architecture of leaf ecophysiology and specialized metabolism in cultivated sunflower. However, because self‐compatibility is a derived quantitative trait in cultivated H. annuus, trait linkage to divergent phenotypic traits may have partially arisen as a potential unintended consequence of historical breeding practices and selection for yield. [ABSTRACT FROM AUTHOR]

In modern agriculture, nano-priming represents an innovative approach, harnessing the power of nanotechnology to enhance crop yields and nutrition. However, to effectively harness the potential of nanoparticles (NPs) for agriculture applications, understanding their mode of action and optimal application rates for positive effects on microgreen growth and physiology is critical. In this interdisciplinary study, we investigated the priming of sunflower seeds with a range of concentrations (25, 50, and 100 mg/L) of ferric oxide (Fe2O3) nanoparticles (FeNPs) and compared them with control samples. Our findings revealed a significant increase in plant biomass, leaf size, and photosynthetic activity in treated samples. The activities of photosystems I and II increased with higher FeNPs concentration. The treated samples exhibited elevated levels of total phenolics, anthocyanin, and antioxidant enzyme activity, along with increased macronutrients and micronutrients. These findings highlight the potential of FeNPs as a promising tool for enhancing plant growth and physiology in sunflower microgreens. [ABSTRACT FROM AUTHOR]

In saline conditions, establishing healthy seedlings is crucial for the productivity of sunflowers (Helianthus annuus L.). Excessive potassium (K+) from irrigation water or overfertilization, similar to sodium (Na+), could adversely affect sunflower growth. However, the effects of salt stress caused by varying K/Na ratios on the establishment of sunflower seedlings have not been widely studied. We conducted a pot experiment in a greenhouse, altering the K/Na ratio of a soil solution to grow sunflower seedlings. We tested three saline solutions with K/Na ratios of 0:1 (P0S1), 1:1 (P1S1), and 1:0 (P1S0) at a constant concentration of 4 dS m−1, along with a control (CK, no salt added), with five replicates. The solutions were applied to the pots via capillary rise through small holes at the bottom. The results indicate that different K/Na ratios significantly influenced ion-selective uptake and transport in crop organs. With an increasing K/Na ratio, the K+ concentration in the roots, stems, and leaves increased, while the Na+ concentration decreased in the roots and stems, with no significant differences in the leaves. Furthermore, an excessive K/Na ratio (P1S0) suppressed the absorption and transportation of Mg2+, significantly reducing the Mg2+ concentration in the stems and leaves. A lower leaf Mg2+ concentration reduced chlorophyll concentration, impairing photosynthetic performance. The lowest plant height, leaf area, dry matter, and shoot/root ratio were observed in P1S0, with reductions of 27%, 48%, 48%, and 13% compared to CK, respectively. Compared with CK, light use efficiency and CO2 use efficiency in P1S0 were significantly reduced by 13% and 10%, respectively, while water use efficiency was significantly increased by 9%. Additionally, improved crop morphological and photosynthetic performance was observed in P1S1 and P0S1 compared with P1S0. These findings underscore the critical role of optimizing ion composition in soil solutions, especially during the sensitive seedling stage, to enhance photosynthesis and ultimately to improve the plant's establishment. We recommend that agricultural practices in saline regions incorporate tailored irrigation and fertilization strategies that prioritize optimal K/Na ratios to maximize crop performance and sustainability. [ABSTRACT FROM AUTHOR]

The exogenous application of oxalic acid is a potential approach to amplifying phytoremediation performance on Cd-contaminated soils. However, few studies explore the optimal oxalic acid application regime from a perspective of coupling different concentrations and timings to maximize Cd removal rate. Given this, a pot experiment was conducted using oil sunflower (Helianthus annuus L.) as the test plant. Oxalic acid was added to the pots at concentrations of 1, 2, 3, 4, 5, and 6 mmol/kg at 20, 30, 40, and 50 days after emergence. A control (CK) without exogenous oxalic acid was also included. We examined the discrepancies in various soil Cd forms, sunflower height, plant non-protein thiol (NPT) levels, and soil Cd remediation efficiency under different oxalic acid application regimes. The results showed that applying oxalic acid at a concentration of 4 mmol/kg reduced the proportion of Fe-Mn oxide Cd and organic Cd compared to the control (CK), while increased the proportion of available Cd. The optimal application time is 30 or 40 days after emergence. The addition of exogenous oxalic acid promoted the growth of sunflowers, with the greatest increase in plant height observed when 4 mmol/kg oxalic acid was applied at 30 days after emergence. Exogenous oxalic acid enhanced the absorption of Cd by sunflower roots, with the total Cd accumulation in roots, stems, and leaves being higher than in the control (CK). When 4 mmol/kg oxalic acid was applied at 30 days after emergence, the total Cd accumulation in roots, stems, and leaves was highest. Under different application times and concentration levels of oxalic acid, Cd accumulation was highest in roots, followed by leaves, with stems showing the lowest accumulation. The NPT content in each part is as follows: root > stem > leaf. Applying 5 mmol/kg oxalic acid after 30 days of sunflower emergence resulted in relatively higher total NPT content in roots, stems, and leaves compared to the control (CK). The TOPSIS model was used for comprehensive evaluation, which showed that 4 mmol/kg oxalic acid application at 30 days after emergence could be used as the optimal oxalic acid application regime for phytoremediation. These findings indicate that the addition of oxalic acid effectively promoted the absorption of Cd by sunflower and increased the efficiency of Cd removal from the rhizosphere soil, with the optimal removal of soil Cd achieved by applying oxalic acid at a concentration of 4 mmol/kg 30 days after the emergence of oilseed sunflower seedlings. [ABSTRACT FROM AUTHOR]

This study evaluates the phytotoxic potential of methanolic extracts from six Asteraceae species: Wedelia chinensis, Helianthus annuus, Cosmos bipinnatus, Tagetes erecta, Tithonia diversifolia, and Zinnia elegans. The extracts were tested at concentrations of 0.03, 0.1, 0.3, and 1.0 g/mL to assess their inhibitory effects on the radicle and hypocotyl lengths of Echinochloa crus‐galli and Echinochloa colona. The two most potent species, C. bipinnatus and T. diversifolia, were further evaluated using extracts from their roots, stems, and leaves. Among these, C. bipinnatus leaf extracts showed the most significant phytotoxicity and were tested at 20, 40, and 60 days of plant age. At 0.03 g/mL, C. bipinnatus extract inhibited the hypocotyl and radicle lengths of E. colona by 23.01% and 56.45%, and E. crus‐galli by 8.5% and 36.35%, respectively. At 1.0 g/mL, the extract inhibited the hypocotyl lengths of E. colona and E. crus‐galli by 97.54% and 88.15%, and the radicle lengths by 93.52% and 99.99%, respectively. The 60‐day‐old C. bipinnatus leaf extract exhibited the highest inhibitory effect, correlating with the identification of key allelochemicals such as cinnamic acid, caffeic acid, coumaric acid, ferulic acid, 2‐4 dimethohydroxy benzoic acid, and salicylic acid. These findings suggest that the 60‐day‐old C. bipinnatus leaf extracts have strong potential for use in the biological control of these weed species, offering a promising avenue for the development of natural herbicides. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.), known for its adaptability and high yield potential, is vital in global edible oil production. Estimating genetic diversity is a key pre-breeding activity in crop breeding. The current study comprised of 48 genotypes which were assessed for their biometrical traits at department of Oilseeds, Tamil Nadu Agricultural University, during the rainy season of 2022. The lines were subsequently characterised using 103 simple sequence repeat (SSR) markers for molecular diversity analysis. The results indicated that the net nucleotide distances indicated varying genetic divergence, with subpopulations II and V showing the highest (0.056) and I and IV the lowest (0.014). Subpopulation IV exhibited the highest heterozygosity (0.352), while subpopulation III had the lowest heterozygosity and a low Fst (0.173). Principal components analysis (PCA) and hierarchical cluster analysis were employed for assessing the morphological diversity, facilitating genotype grouping and parent selection for breeding programs. The first four components cumulatively accounted for 86.72% of the total variation. Cluster Analysis grouped 48 sunflower genotypes into three clusters based on genetic diversity. COSF 13B stands out for its high head diameter, oil content, seed yield, and oil yield based on mean performance of morphological data. Principal coordinate analysis (PCoA) mirrored the groupings from the Neighbor Joining method, with the first three components explaining 27.24% of the total variation. Molecular data analysis identified five distinct clusters among the germplasm. By integrating morphological and molecular marker data with genetic distance analysis, substantial diversity was revealed with the genotypes RHA 273 and GMU 325 consistently demonstrated high oil yield per plant. The genotypes GMU 477, GMU 450, COSF 13B, RHA 102, CMS 1103B, and RHA GPR 58 have been identified as suitable parents for enhancing oil content in sunflower breeding programs. These findings also aid in selecting SSR markers for genotype characterization and in choosing diverse parents for breeding programs. [ABSTRACT FROM AUTHOR]

The cultivation of sunflower (Helianthus annuus L.) as a cut flower stands out in floriculture due to its aesthetic beauty and commercial value. Understanding how cut sunflower genotypes adapt to different edaphoclimatic regions and management practices is essential to optimize flower quality and productivity. This study aimed to evaluate the effect of plant density and location on the development, growth, and quality of cut sunflower in tropical and subtropical environments. Plant densities of 10, 20, 30, 40, and 50 plants/m2 were evaluated in tropical climate and subtropical climate using a randomized block design in a factorial scheme. Results showed significant differences between locations for plant height, capitulum and stem diameter, final number of leaves, leaf area, leaf area index, phyllochron, and the developmental cycle. Plant density significantly influenced these variables except for plant height and developmental cycle. The interaction between location and plant density was significant only for capitulum diameter and final leaf number. The findings indicate that both planting density and location significantly influence the developmental cycle of cut sunflowers, with lower densities favoring more robust plants at harvest. A density of 30 plants/m2 is recommended for efficient space use without significantly compromising floral stem quality. All produced stems are marketable, suggesting that adjusting planting density can optimize production without compromising quality, adapting to specific regional conditions. [ABSTRACT FROM AUTHOR]

Trichomes play a key role in both heavy metal tolerance and herbivory defense, and both stressors have been shown to induce increased trichome density. However, the combined effect of these stressors on trichome density in general, and specifically on metal-hyperaccumulating plants, has yet to be examined. The aim of this study was to test the effect of cadmium availability and herbivory on leaf trichome density and herbivore deterrence in the metal hyperaccumulator Helianthus annuus. To test this, H. Annuus plants were grown in control pots or pots inoculated with 10 mg/kg cadmium and were subjected to either no herbivory or simulated herbivory using mechanical damage and foliar jasmonic acid application. Herbivore deterrence was tested in a feeding assay using Spodoptera littoralis caterpillars. Interestingly, while the trichome density of H. annuus increased by 79% or 53.5% under high cadmium availability or simulated herbivory, respectively, it decreased by 26% when the stressors were combined. Furthermore, regardless of cadmium availability, simulated herbivory induced a 40% increase in deterrence of S. littoralis. These findings suggest that the combination of metal availability and herbivory might present excessive stress to hyperaccumulators. Moreover, they suggest that the risk of metal bioaccumulation in phytoremediation can be reduced by simulated herbivory. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) plays an essential role in meeting the demand for edible oil worldwide. The yield of sunflower seeds encompasses several component traits, including the disc diameter. Over three consecutive years, 2019, 2020, and 2022, we assessed phenotypic variation in disc diameter across a diverse set of sunflower accessions (N = 342) in replicated field trials. Upon aggregating the phenotypic data from multiple years, we estimated the broad sense heritability (H2) of the disc diameter trait to be 0.88. A subset of N = 274 accessions was genotyped by using the tunable genotyping‐by‐sequencing (tGBS) method, resulting in 226,779 high‐quality SNPs. Using these SNPs and the disc diameter phenotype, we conducted a genome‐wide association study (GWAS) employing two statistical approaches: the mixed linear model (MLM) and the fixed and random model circulating probability unification (farmCPU). The MLM and farmCPU GWAS approaches identified 106 and 8 significant SNPs located close to 53 and 21 genes, respectively. The MLM analysis identified two significant peaks: a prominent signal on chromosome 10 and a relatively weaker signal on chromosome 16, both of which were also detected by farmCPU. The genetic loci associated with disc diameter, as well as the related candidate genes, present promising avenues for further functional validation and serve as a basis for sunflower oil yield improvement. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus) is a globally significant field crop, and disease resistance is crucial for ensuring yield stability and crop quality. Verticillium dahliae is a notorious soilborne pathogen that causes Verticillium Wilt (VW) and threatens sunflower production worldwide. In this study, we conducted a comprehensive assessment of sunflower resistance to V. dahliae across 231 sunflower cultivar lines, from the Sunflower Association Mapping (SAM) population. We employed EMMAX and ridge regression best linear unbiased prediction (rrBLUP) and identified 148 quantitative trait loci (QTLs) and 23 putative genes associated with V. dahliae resistance, including receptor like kinases, cell wall modification, transcriptional regulation, plant stress signalling and defense regulation genes. Our enrichment and quantitative real-time PCR validation results highlight the importance of membrane vesicle trafficking in the sunflower immune system for efficient signaling and defense upon activation by V. dahliae. This study also reveals the polygenic architecture of V. dahliae resistance in sunflowers and provides insights for breeding sunflower cultivars resistant to VW. This research contributes to ongoing efforts to enhance crop resilience and reduce yield losses due to VW, ultimately benefiting sunflower growers and the agricultural sector. [ABSTRACT FROM AUTHOR]

The microbiological and biochemical properties of a goat cheese produced using Helianthus annuus (sunflower) seed extract as a coagulant and the potentially probiotic autochthonous culture Limosilactobacillus mucosae CNPC007 were examined in comparison to a control cheese devoid of the autochthonous culture. Throughout a 60-day storage period at 6 ± 1 °C, lactobacilli maintained a count of above 8 log CFU/g. Additionally, its viability in cheeses subjected to the in vitro gastrointestinal conditions demonstrated improvement over this period. Specifically, the recovery of lactobacilli above 6 log CFU/g was observed in 16.66% of the samples in the first day, increasing to 66.66% at both 30 and 60 days. While total coliforms were detected in both cheese trials, this sanitary parameter exhibited a decline in L. mucosae cheeses during storage, falling below the method threshold (<3 MPN/g) at 60 days. This observation suggests a potential biopreservative effect exerted by this microorganism, likely attributed to the higher acidity of L. mucosae cheeses at that point (1.80 g/100 g), which was twice that of the control trial (0.97 g/100 g). Furthermore, distinct relative proportions of >30 kDa, 30–20 kDa, and <20 kDa proteins during storage was verified for L. mucosae and control cheeses. Consequently, either the H. annuus seed extract or the L. mucosae CNPC007 autochthonous culture influenced the biochemical properties of the cheese, particularly in terms of proteolysis. Moreover, L. mucosae CNPC007 acidification property resulted in a biopreservative effect throughout the storage period, indicating the potential as a promising source of probiotics for this product. [ABSTRACT FROM AUTHOR]

Intracellular plant defense against pathogens is mediated by a class of disease resistance genes known as NB‐LRRs or NLRs (R genes). Many of the diseases these genes protect against are more prevalent in regions of higher rainfall, which provide better growth conditions for the pathogens. As such, we expect a higher selective pressure for the maintenance and proliferation of R genes in plants adapted to wetter conditions. In this study, we enriched libraries for R genes using RenSeq from baits primarily developed from the common sunflower (Helianthus annuus) reference genome. We sequenced the R gene libraries of Silphium integrifolium Michx, a perennial relative of sunflower, from 12 prairie remnants across a rainfall gradient in the Central Plains of the United States, with both Illumina short‐read (n = 99) and PacBio long‐read (n = 10) approaches. We found a positive relationship between the mean effective annual precipitation of a plant's source prairie remnant and the number of R genes in its genome, consistent with intensity of plant pathogen coevolution increasing with precipitation. We show that RenSeq can be applied to the study of ecological hypotheses in non‐model relatives of model organisms. [ABSTRACT FROM AUTHOR]

The state of Rio Grande do Sul (RS) is the third largest sunflower producer in Brazil. This study verified the existence of linear relationships between grain yield, oil content, and oil yield in sunflower (Helianthus annuus L.) genotypes evaluated in RS. The data on grain yield (GY), oil content (OC), and oil yield (OY) were obtained from 73 sunflower cultivar trials in 21 municipalities in RS from 1999 to 2018. Scatter diagrams were createdto investigate the relationships between the variables GY, OC, and OY. Then, Pearson's linear correlation coefficient (r) was calculated between the variables, and the Student's t-test was performed at a 5% significance level. There is a positive and significant linear relationship between PG and OY. However, no linear relationship was found between grain yield and oil content in sunflower genotypes. Additionally, a positive linear association of high magnitude (r = 0.9672) was observed between grain yield and oil yield, while a low magnitude (r = 0.2245) was found between oil content and oil yield. [ABSTRACT FROM AUTHOR]

Insufficient dietary vitamin intake can lead to severe health conditions in humans. Improving the vitamin E (VE) content of food crops such as rice through breeding is an economical and effective means to alleviate this problem. In this study, Homogentisate phytyltransferase (HPT) and γ-tocopherol methyltransferase (γ-TMT), two genes derived from sunflower (Helianthus annuus L., a high VE species), were introduced into an elite rice (Oryza sativa L.) cultivar "Ningjing 7" for biofortification. We verified the successful expression of the two genes in multiple transformation events. High-performance liquid chromatography revealed that transgenic plants expressing either HaHPT alone or HaHPT and HaTMT accumulate more VE compared with the wild type. We also revealed that the level of α-tocopherol, the form of VE with the highest biological activity, had increased to 2.33 times in transgenic HaTMT plants compared with the wild type. Transcriptome analysis revealed that the expression levels of some chlorophyll synthesis pathway genes related to VE precursor synthesis significantly increased during grain filling in transgenic rice grains. No difference in agronomic traits was observed between the transgenic plants and their wild type except for a slightly reduced plant height associated with the transgenic plants. These data demonstrate that the heterologous expression of HaHPT gene is effective in increasing the total VE content, while HaTMT plays an important role in the relative abundance of α-tocopherol in rice grains. This study demonstrates a promising strategy for breeding rice with elevated VE content via metabolic engineering. [ABSTRACT FROM AUTHOR]

Weedy sunflowers can cause severe yield losses and have recently been reported in several regions of Europe. We present the results of a survey of 24 grid cells 1 km2 in size on the distribution of weedy sunflowers in two different regions in Austria. Our results showed that weedy sunflowers (Helianthus annuus L.) occur in various crops (oil pumpkin, soybean, and maize). While most occurrences were small, a few fields were heavily infested (> 500 individuals) and weedy sunflowers reached cover values of up to 25%. The average number was 175 plants/km2 across all grid cells surveyed, with an average of 324 plants/km2 in the 13 infested grid cells and a maximum of approx. 1000 plants in the most heavily infested grid cell. The expression of recorded morphological traits (i.e., head number, height, and head diameter) varied considerably between populations of weedy sunflower, escaped sunflower, and cultivated sunflower. This study is the first to assess the infestation of weedy sunflowers in fields in Austria. We found evidence of the potentially substantial impact of weedy sunflowers on crop yields. Our findings highlight the need for further monitoring and controlling of weedy sunflowers in fields. [ABSTRACT FROM AUTHOR]

Virus-Induced Gene Silencing (VIGS) is a versatile tool in plant science, yet its application to non-model species like sunflower demands extensive optimization due to transformation challenges. In this study, we aimed to elucidate the factors that significantly affect the efficiency of Agrobacterium-VIGS in sunflowers. After testing a number of approaches, we concluded that the seed vacuum technique followed by 6 h of co-cultivation produced the most efficient VIGS results. Genotype-dependency analysis revealed varying infection percentages (62–91%) and silencing symptom spreading in different sunflower genotypes. Additionally, we explored the mobility of tobacco rattle virus (TRV) and phenotypic silencing manifestation (photo-bleaching) across different tissues and regions of VIGS-infected sunflower plants. We showed the presence of TRV is not necessarily limited to tissues with observable silencing events. Finally, time-lapse observation demonstrated a more active spreading of the photo-bleached spots in young tissues compared to mature ones. This study not only offers a robust VIGS protocol for sunflowers but also provides valuable insights into genotype-dependent responses and the dynamic nature of silencing events, shedding light on TRV mobility across different plant tissues. [ABSTRACT FROM AUTHOR]

Short tandem repeat (STR) variation is rarely explored as a contributor to adaptive evolution. An intriguing mechanism involving STRs suggests that STRs function as "tuning knobs" of adaptation whereby stepwise changes in STR allele length have stepwise effects on phenotypes. Previously, we tested the predictions of the "tuning knob" model at the gene expression level by conducting an RNA-Seq experiment on natural populations of common sunflower (Helianthus annuus L.) transecting a well-defined cline from Kansas to Oklahoma. We identified 479 STRs with significant allele length effects on gene expression (eSTRs). In this study, we expanded the range to populations further north and south of the focal populations and used a targeted approach to study the relationship between STR allele length and gene expression in five selected eSTRs. Seeds from 96 individuals from six natural populations of sunflower from Nebraska and Texas were grown in a common garden. The individuals were genotyped at the five eSTRs, and gene expression was quantified with qRT-PCR. Linear regression models identified that eSTR length in comp26672 was significantly correlated with gene expression. Further, the length of comp26672 eSTR was significantly correlated with latitude across the range from Nebraska to Texas. The eSTR locus comp26672 was located in the CHUP1 gene, a gene associated with chloroplast movement in response to light intensity, which suggests a potential adaptive role for the eSTR locus. Collectively, our results from this targeted study show a consistent relationship between allele length and gene expression in some eSTRs across a broad geographical range in sunflower and suggest that some eSTRs may contribute to adaptive traits in common sunflower. [ABSTRACT FROM AUTHOR]

Fluorescence photography was used to evaluate the effects of bentazon, an herbicide that inhibits electron transport in photosystem II, on sunflower, taken as a model plant. We measured chlorophyll fluorescence to visualize the penetration, distribution, and effect of the herbicide on the plant. Our results showed that bentazon penetrates the leaf within 10–16 min, reaching full depth within 40 min. Also, we show that the herbicide is distributed along the conducting tissues of the leaf. The presence of necrotic spots, as well as the size of increased-fluorescence areas, were positively correlated to the concentration of herbicide. These findings suggest that fluorescence imaging may be a useful tool for observing the absorption and distribution of photosystem II-inhibiting herbicides in plants as an alternative to radioactive labeling in some cases. [ABSTRACT FROM AUTHOR]

We present a reference genome for the federally endangered Gaviota tarplant, Deinandra increscens subsp. villosa (Madiinae, Asteraceae), an annual herb endemic to the Central California coast. Generating PacBio HiFi, Oxford Nanopore Technologies, and Dovetail Omni-C data, we assembled a haploid consensus genome of 1.67 Gb as 28.7 K scaffolds with a scaffold N50 of 74.9 Mb. We annotated repeat content in 74.8% of the genome. Long terminal repeats (LTRs) covered 44.0% of the genome with Copia families predominant at 22.9% followed by Gypsy at 14.2%. Both Gypsy and Copia elements were common in ancestral peaks of LTRs, and the most abundant element was a Gypsy element containing nested Copia/Angela sequence similarity, reflecting a complex evolutionary history of repeat activity. Gene annotation produced 33,257 genes and 68,942 transcripts, of which 99% were functionally annotated. BUSCO scores for the annotated proteins were 96.0% complete of which 77.6% was single copy and 18.4% duplicates. Whole genome duplication synonymous mutation rates of Gaviota tarplant and sunflower (Helianthus annuus) shared peaks that correspond to the last Asteraceae polyploidization event and subsequent divergence from a common ancestor at ∼27 MYA. Regions of high-density tandem genes were identified, pointing to potentially important loci of environmental adaptation in this species. [ABSTRACT FROM AUTHOR]

To maximize their fitness, plants have to adjust their allocation strategy according to their abiotic and biotic environments. Plants can use the ratio of red to far‐red light (R:FR) to sense neighbours, allowing them to modify their growth in response to aboveground competition.In this study, we used supplemental FR light to artificially lower the R:FR of the lower leaves of common sunflowers (Helianthus annuus) to examine how plants change their growth in response to the threat of neighbours. We combined this treatment with a nitrogen fertilization treatment to investigate how responses to neighbour‐detection interact with nitrogen limitation.Plants grown in low R:FR increased in height at the expense of root growth, resulting in nitrogen limitation that restricted leaf growth. However, we found that plants reduced their nitrogen investment into leaves in low R:FR. By weakening the nitrogen sink strength of these lower leaves before they experienced low photosynthetically active radiation, plants were able to preemptively allocate nitrogen to leaves higher in the canopy.Plants responded to the perception of neighbours by simultaneously diverting resources from root growth to stem elongation and from leaves threatened by neighbours to leaves that would pose a threat to neighbours. This whole‐plant response to neighbour‐detection enables plants to change their allocation in a way that simultaneously manages their limited nitrogen and prepares them for future light competition. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Drought stress poses a significant obstacle to agricultural productivity, particularly in the case of oilseed crops such as sunflower (Helianthus annuus L.). Selenium (Se) is a fundamental micronutrient that has been recognized for its ability to enhance plant resilience in the face of various environmental stresses. The FH-770 sunflower variety was cultivated in pots subjected to three stress levels (100% FC, 75% FC, and 50% FC) and four Se application rates (0 ppm, 30 ppm, 60 ppm, and 90 ppm). This research aimed to investigate the effect of exogenously applied Se on morpho-physiological and biochemical attributes of sunflower to improve the drought tolerance. Foliar Se application significantly lowered H2O2 (hydrogen peroxide; ROS) (20.89%) accumulation that markedly improved glycine betaine (GB) (74.46%) and total soluble protein (Pro) (68.63%), improved the accumulation of ascorbic acid (AA) (25.51%), total phenolics (TP) (39.34%), flavonoids (Flv) (73.16%), and anthocyanin (Ant) (83.73%), and improved the activity of antioxidant system superoxide dismutase (SOD) (157.63%), peroxidase (POD) (100.20%), and catalase (CAT) (49.87%), which ultimately improved sunflower growth by 36.65% during drought stress. Supplemental Se significantly increased shoot Se content (93.86%) and improved calcium (Ca2+), potassium (K+), and sodium (Na+) ions in roots by 36.16%, 42.68%, and 63.40%, respectively. Seleniumsupplements at lower concentrations (60 and 90 ppm) promoted the growth, development, and biochemical attributes of sunflowers in controlled and water-deficient circumstances. However, selenium treatment improved photosynthetic efficiency, plant growth, enzymatic activities, osmoregulation, biochemical characteristics, and nutrient balance. The mechanisms and molecular processes through which Se induces these modifications need further investigation to be properly identified. [ABSTRACT FROM AUTHOR]

The quality of river and borehole water fluctuates because of both agricultural and industrial pollutants. Surface runoff during the rainy seasons is high which promote increased turbidity levels in water sources, and this exerts pressure on the quality and usability of the water for domestic use. Unfortunately, most municipalities in developing countries are poor to afford conventional water treatment methods. This study assessed the use of natural coagulants extracted from sunflower seeds for turbidity treatment. Water samples were collected during summer, winter, and autumn from 10 randomly selected groundwater sources and three segments of the Mwerahari River in Buhera District, Zimbabwe. Results captured seasonal turbidity variations across the river segments and the boreholes. Summer season recorded the maximum average levels of turbidity (76 NTU) while autumn and winter recorded 38.7 NTU 36.7 NTU, respectively. Water turbidity levels were above the acceptable 5 NTU Standard Association of Zimbabwe and WHO. The maximum removal efficiency of turbidity was achieved at 80 min at the dose of 4 g/l. These results revealed that the removal efficiency of 95% with 4.6 NTU turbidity is a function of dose; removal efficiency increases as dose of coagulant increases. These results demonstrated that sunflower seed is an effective low-cost natural coagulant for turbidity water treatment. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.), a vital crop for global vegetable oil production, encounters sustainability challenges in its cultivation. This study assesses the effects of incorporating a winter cover crop (CC), Avena sativa (L.), on the subsequent growth of sunflower crops and the vitality of their rhizosphere microbial communities over a two-year period. It examines the impact of two methods for suppressing winter CC--chemical suppression using glyphosate and mechanical suppression via rolling--both with and without the addition of phosphorus (P) starter fertilizer. These approaches are evaluated in comparison to the regional best management practices for sunflower cultivation, which involve a preparatory chemical fallow period and the subsequent application of starter P fertilizer. The methodology utilized Illumina sequencing for the analysis of rhizosphere bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) amplicons. Findings indicate a significant improvement (9-37%) in sunflower growth parameters (plant height, stem diameter, head diameter, and head dry weight) when cultivated after glyphosate-suppressed winter CC compared to the chemical fallows. Conversely, rolling of winter CC generally negatively affected sunflower growth. Rhizosphere bacterial communities following chemical suppression of winter CC showed greater Pielou's evenness, indicating a uniform distribution of species. In general, this treatment had more detrimental effects on beneficial sunflower rhizosphere bacteria such as Hymenobacter and Pseudarthrobacter than rolling of the winter CC, suggesting that the overall effect on sunflower growth may be mitigated by the redundancy within the bacterial community. As for fungal diversity, measured by the Chao-1 index, it increased in sunflowers planted after winter CC and receiving P fertilization, underscoring nutrient management's role in microbial community structure. Significant positive correlations between fungal diversity and sunflower growth parameters at the reproductive stage were observed (r = 0.41-0.72; p < 0.05), highlighting the role of fungal communities in plant fitness. The study underscores the positive effects of winter CC inclusion and management for enhancing sunflower cultivation while promoting beneficial microbes in the crop's rhizosphere. We advocate for strategic winter CC species selection, optimization of mechanical suppression techniques, and tailored phosphorus fertilization of sunflower to foster sustainable agriculture. [ABSTRACT FROM AUTHOR]

Summary: Vascular systems are intimately related to the shape and spatial arrangement of the plant organs they support. We investigate the largely unexplored association between spiral phyllotaxis and the vascular system in Asteraceae flower heads.We imaged heads of eight species using synchrotron‐based X‐ray micro‐computed tomography and applied original virtual reality and haptic software to explore head vasculature in three dimensions. We then constructed a computational model to infer a plausible patterning mechanism.The vascular system in the head of the model plant Gerbera hybrida is qualitatively different from those of Bellis perennis and Helianthus annuus, characterized previously. Cirsium vulgare, Craspedia globosa, Echinacea purpurea, Echinops bannaticus, and Tanacetum vulgare represent variants of the Bellis and Helianthus systems. In each species, the layout of the main strands is stereotypical, but details vary. The observed vascular patterns can be generated by a common computational model with different parameter values.In spite of the observed differences of vascular systems in heads, they may be produced by a conserved mechanism. The diversity and irregularities of vasculature stand in contrast with the relative uniformity and regularity of phyllotactic patterns, confirming that phyllotaxis in heads is not driven by the vasculature. See also the Commentary on this article by Burian & Kierzkowski, 243: 10–13. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus) is an important oil crop, ranking behind soybean, peanut, and rapeseed in terms of planting area in China. Throughout its cultivation, sunflower is susceptible to various diseases that can significantly reduce its seed yield. Among them, Fusarium species pose a major threat to numerous crops. The accurate identification of Fusarium species responsible for specific diseases is crucial for developing effective control measures. In Inner Mongolia, sunflower disk rot (SDR) has been observed in various sunflower fields, with an average infection rate of approximately 8.50%. The infection rate can reach up to 11.67% in certain highly susceptible cultivars. Samples of diseased sunflower receptacles were collected from different locations, and Koch's postulates were employed to identify the causal agent. The results confirmed Fusarium verticillioides as the pathogen responsible for SDR. Fungicide toxicity tests were conducted, screening six fungicides for efficacy against F. verticillioides. Fludioxonil and Flutolanil were identified as the most effective, with EC50 values of 0.05 µg/mL (R = 0.9825) and 0.96 µg/mL (R = 0.9964), respectively. This is the first report of SDR caused by F. verticillioides, and it will alert sunflower researchers to include SDR in the disease list, so as to control sunflower diseases with integrated management strategies successfully. [ABSTRACT FROM AUTHOR]

The sunflower (Helianthus annuus L.) is one of the most essential oil crops in the world. Several component traits, including flowering time, plant height, stem diameter, seed weight, and kernel weight, determine sunflower seed and oil yield. Although the genetic mechanisms governing the variation of these yield-related traits have been studied using various approaches, genome-wide association studies (GWAS) have not been widely applied to sunflowers. In this study, a set of 342 sunflower accessions was evaluated in 2019 and 2020 using an incomplete randomized block design, and GWAS was conducted utilizing two complementary approaches: the mixed linear model (MLM) and the fixed and random model circulating probability unification (farmCPU) model by fitting 226,779 high-quality SNPs. As a result, GWAS identified a number of trait-associated SNPs. Those SNPs were located close to several genes that may serve as a basis for further molecular characterization and provide promising targets for sunflower yield improvement. [ABSTRACT FROM AUTHOR]

Purpose. To study the influence of steppe and forest-steppe climatic conditions on the yield, oil content in seeds and fatty acid composition of oil in new sunflower varieties of high oleic and oilseed use. Methods. The research was conducted in accordance with "Methods of qualification examination of plant varieties for their suitability for distribution in Ukraine (general part)" and "Methods of qualification examination of plant varieties for their suitability for distribution. Methods of determining quality indicators of plant production". The following methods were used in the research: laboratory, comparison, generalisation, mathematical statistics, analysis and synthesis to draw conclusions. Results. The fatty acid composition of the seeds of new varieties of sunflower (Helianthus annuus L.) of high oleic and oilseed use, grown in different soil and climatic conditions, was studied. According to the results of the analysis in the steppe zone, the variety 'LG50648' has the highest economic and value characteristics: oil content (51,0%), oleic acid (85.1%), yield (3.11 t/ha); varieties 'SULIANO' and 'MAS 908HOCP' - yield (3.40 and 3.91 t/ha) and oleic acid content (85.8 and 86.1%) regardless of the growing conditions. It was found that high oleic sunflower varieties 'MAS 908HOCP', 'LG50648', 'SULIANO' grown under steppe and forest-steppe conditions yielded higher quality oil. The maximum content of oleic acid in 2022-2023 was characteristic of the seeds of the varieties 'MAS 908HOCP' (86.1% in the steppe and 85.8% in the forest steppe) and 'SULIANO'. The hi ghest linoleic acid content was obtained in the seeds of the oilseed use varieties 'STK104' (62.9% in the steppe and 58.5% in the forest steppe) and 'STK103' (61.2% in the forest steppe). Among the high oleic varieties, the best results were obtained with 'LG50648' (5.7% in the steppe and 5.9% in the forest steppe). Conclusions. Oil content of sunflower varieties and fatty acid composition are determined by varietal characteristics of sunflower and environmental conditions. Modern sunflower varieties, which are included in the State Register of Plant Varieties of Ukraine, have high yield potential and can provide a large yield of vegetable oil per unit area. Agroclimatic conditions have different effects on the gross seed yield and oil quality in the conditions of the forest steppe and steppe of Ukraine. [ABSTRACT FROM AUTHOR]

Stress-associated proteins (SAPs) are known to play an important role in plant responses to abiotic stresses. This study systematically identified members of the sunflower SAP gene family using sunflower genome data. The genes of the sunflower SAP gene family were analyzed using bioinformatic methods, and gene expression was assessed through fluorescence quantification (qRT-PCR) under salt and drought stress. A comprehensive analysis was also performed on the number, structure, collinearity, and phylogeny of seven Compositae species and eight other plant SAP gene families. The sunflower genome was found to have 27 SAP genes, distributed across 14 chromosomes. The evolutionary analysis revealed that the SAP family genes could be divided into three subgroups. Notably, the annuus variety exhibited amplification of the SAP gene for Group 3. Among the Compositae species, C. morifolium demonstrated the highest number of collinearity gene pairs and the closest distance on the phylogenetic tree, suggesting relative conservation in the evolutionary process. An analysis of gene structure revealed that Group 1 exhibited the most complex gene structure, while the majority of HaSAP genes in Group 2 and Group 3 lacked introns. The promoter analysis revealed the presence of cis-acting elements related to ABA, indicating their involvement in stress responses. The expression analysis indicated the potential involvement of 10 genes (HaSAP1, HaSAP3, HaSAP8, HaSAP10, HaSAP15, HaSAP16, HaSAP21, HaSAP22, HaSAP23, and HaSAP26) in sunflower salt tolerance. The expression of these 10 genes were then examined under salt and drought stress using qRT-PCR, and the tissue-specific expression patterns of these 10 genes were also analyzed. HaSAP1, HaSAP21, and HaSAP23 exhibited consistent expression patterns under both salt and drought stress, indicating these genes play a role in both salt tolerance and drought resistance in sunflower. The findings of this study highlight the significant contribution of the SAP gene family to salt tolerance and drought resistance in sunflower. [ABSTRACT FROM AUTHOR]

The development of floral organs, crucial for the establishment of floral symmetry and morphology in higher plants, is regulated by MADS-box genes. In sunflower, the capitulum is comprised of ray and disc florets with various floral organs. In the sunflower long petal mutant (lpm), the abnormal disc (ray-like) floret possesses prolongated petals and degenerated stamens, resulting in a transformation from zygomorphic to actinomorphic symmetry. In this study, we investigated the effect of MADS-box genes on floral organs, particularly on petals, using WT and lpm plants as materials. Based on our RNA-seq data, 29 MADS-box candidate genes were identified, and their roles on floral organ development, especially in petals, were explored, by analyzing the expression levels in various tissues in WT and lpm plants through RNA-sequencing and qPCR. The results suggested that HaMADS3, HaMADS7, and HaMADS8 could regulate petal development in sunflower. High levels of HaMADS3 that relieved the inhibition of cell proliferation, together with low levels of HaMADS7 and HaMADS8, promoted petal prolongation and maintained the morphology of ray florets. In contrast, low levels of HaMADS3 and high levels of HaMADS7 and HaMADS8 repressed petal extension and maintained the morphology of disc florets. Their coordination may contribute to the differentiation of disc and ray florets in sunflower and maintain the balance between attracting pollinators and producing offspring. Meanwhile, Pearson correlation analysis between petal length and expression levels of MADS-box genes further indicated their involvement in petal prolongation. Additionally, the analysis of cis-acting elements indicated that these three MADS-box genes may regulate petal development and floral symmetry establishment by regulating the expression activity of HaCYC2c. Our findings can provide some new understanding of the molecular regulatory network of petal development and floral morphology formation, as well as the differentiation of disc and ray florets in sunflower. [ABSTRACT FROM AUTHOR]

Introduction: Arsenate, a metalloid, acting as an analog to phosphate, has a tendency to accumulate more readily in plant species, leading to adverse effects. Methods: In the current study, sunflower seedlings were exposed to 25, 50 and 100 ppm of the arsenic. Results: Likewise, a notable reduction (p<0.05) was observed in the relative growth rate (RGR) by 4-folds and net assimilation rate (NAR) by 75% of Helianthus annuus when subjected to arsenic (As) stress. Nevertheless, the presence of Staphylococcus arlettae, a plant growth-promoting rhizobacterium with As tolerance, yielded an escalation in the growth of H. annuus within Ascontaminated media. S. arlettae facilitated the conversion of As into a form accessible to plants, thereby, increasing its uptake and subsequent accumulation in plant tissues. S. arlettae encouraged the enzymatic antioxidant systems (Superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX) and catalase (CAT)) and non-enzymatic antioxidants (flavonoids, phenolics, and glutathione) in H. annuus seedlings following substantial As accumulation. The strain also induced the host plant to produce osmolytes like proline and sugars, mitigating water loss and maintaining cellular osmotic balance under As-induced stress. S. arlettae rectified imbalances in lignin content, reduced high malonaldehyde (MDA) levels, and minimized electrolyte leakage, thus counteracting the toxic impacts of the metal. Conclusion: The strain exhibited the capability to concurrently encourage plant growth and remediate Ascontaminated growth media through 2-folds rate of biotransformation and bio-mobilization. [ABSTRACT FROM AUTHOR]

Drought is a major agricultural challenge that is expected to worsen with climate change. A better understanding of drought responses has the potential to inform efforts to breed more tolerant plants. We assessed leaf trait variation and covariation in cultivated sunflower (Helianthus annuus L.) in response to water limitation. Plants were grown under four levels of water availability and assessed for environmentally induced plasticity in leaf stomatal and vein traits as well as biomass (performance indicator), mass fractions, leaf area, leaf mass per area, and chlorophyll content. Overall, biomass declined in response to stress; these changes were accompanied by responses in leaf-level traits including decreased leaf area and stomatal size, and increased stomatal and vein density. The magnitude of trait responses increased with stress severity and relative plasticity of smaller-scale leaf anatomical traits was less than that of larger-scale traits related to construction and growth. Across treatments, where phenotypic plasticity was observed, stomatal density was negatively correlated with stomatal size and positively correlated with minor vein density, but the correlations did not hold up within treatments. Four leaf traits previously shown to reflect major axes of variation in a large sunflower diversity panel under well-watered conditions (i.e. stomatal density, stomatal pore length, vein density, and leaf mass per area) predicted a surprisingly large amount of the variation in biomass across treatments, but trait associations with biomass differed within treatments. Additionally, the importance of these traits in predicting variation in biomass is mediated, at least in part, through leaf size. Our results demonstrate the importance of leaf anatomical traits in mediating drought responses in sunflower, and highlight the role that phenotypic plasticity and multi-trait phenotypes can play in predicting productivity under complex abiotic stresses like drought. [ABSTRACT FROM AUTHOR]

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Drought stress poses a significant threat to agricultural productivity, especially in areas susceptible to water scarcity. Sunflower (Helianthus annuus L.) is a widely cultivated oilseed crop with considerable potential globally. Jasmonic acid, a plant growth regulator, plays a crucial role in alleviating the adverse impacts of drought stress on the morphological, biochemical, and physiological characteristics of crops. Experimental detail includes sunflower varieties (Armani Gold, KQS-HSF-1, Parsun, and ESFH-3391), four drought stress levels (0, 25%, 50%, and 75% drought stress), and three levels (0, 40ppm, 80ppm) of jasmonic acid. The 0% drought stress and 0ppm jasmonic acid were considered as control treatments. The experimental design was a completely randomized design with three replicates. Drought stress significantly reduced the growth in all varieties. However, the exogenous application of jasmonic acid at concentrations of 40ppm and 80ppm enhanced growth parameters, shoot and root length (1.93%, 19%), shoot and root fresh weight (18.5%, 25%), chlorophyll content (36%), photosynthetic rate (22%), transpiration rate (40%), WUE (20%), MDA (6.5%), Phenolics (19%), hydrogen peroxide (7%) proline (28%) and glycine betaine (15–30%) under water-stressed conditions, which was closely linked to the increase in stomatal activity stimulated by jasmonic acid. Furthermore, JA 80 ppm was found to be the most appropriate dose to reduce the effect of water stress in all sunflower varieties. It was concluded that the foliar application of JA has the potential to enhance drought tolerance by improving the morphological, biochemical, and physiological of sunflower. [ABSTRACT FROM AUTHOR]

The present investigation was performed to evaluate the effects of various synthetic antioxidants (vitamin A, vitamin E, β-carotene, and BHT) on the oxidation of sunflower oil subjected to accelerated thermal storage at 60 °C for three months (12 weeks). The performance of the antioxidants studied was evaluated using several quality parameters: the free fatty acid value (FFA), primary oxidation (via the peroxide value (PV) and K232 value), secondary oxidation products (via the anisidine value (p-AV) and K270 value), and the total oxidation value (TOTOX). The fatty acid composition (FAC), oxidizability value (COX), iodine value (IV), and pigment content (chlorophyll and carotenoid) were also evaluated. The results revealed that the control sample of sunflower oil exhibited higher susceptibility to oxidative deterioration. Antioxidants at 200 ppm were more effective in preserving the oxidative stability of sunflower oil subjected to accelerated storage compared to the control oil. The smallest increases in all stability parameter indexes were recorded for antioxidant-supplemented sunflower oil. However, the IV and chlorophyll and carotenoid contents were reduced. At 200 ppm, vitamin E and β-carotene showed the greatest stability in sunflower oil, while their combination with vitamin A at 100 ppm of each showed the lowest stability. In addition, synthetic antioxidants provided greater protection against the degradation of polyunsaturated fatty acids (PUFAs). The highest level of PUFA degradation was recorded in the control oil, followed by the oil containing vitamin A. In conclusion, adding synthetic antioxidants to sunflower oil improves its stability during storage. However, some authors associated these molecules with a health risk due to carcinogenic effects as these molecules have been listed as "Generally Recognized As Safe" (GRAS). [ABSTRACT FROM AUTHOR]

Resistance of agricultural crops to herbicides is an important topic that concerns many researchers. One of the most popular groups of herbicides is the imidazolinone group. Resistant forms of crops such as wheat (Triticum aestivum L.), sunflower (Helianthus annuus L.), corn (Zea mays L.), rice (Oryza sativa L.) and oilseed rape (Brassica napus L.) have been developed to this group of herbicides. All crops resistant to this group of herbicides have the commercial name Clearfield®. In this review, the information concerning oilseed rape resistance to the imidazolinone group of herbicides is collected and summarized; it will be useful for breeders and researchers engaged in this direction. This review touches upon the topic of mechanisms of oilseed rape resistance to imidazolinones. Mutation variants known to date, which provide resistance to this group of herbicides, are described, and known molecular markers of them are presented. Approaches to the selection of oilseed rape for resistance to the imidazolinone group of herbicides are mentioned. Various methods of utilizing imidazolinone resistance to improve the purity of hybrid seeds are also considered. [ABSTRACT FROM AUTHOR]

Microorganisms with multiple ecological functions can be a useful biotechnological resource in integrated pest- and disease-management programs. This work aimed to investigate the potential endophytic and virulent effects of a strain of Purpureocillium lilacinum on organic cultivation in Brazil. Specifically, the strain's ability to establish itself as an endophyte in common bean, soybean, and sunflower plants when inoculated via seed was evaluated. Furthermore, its antifungal activity against phytopathogens and its pathogenicity and virulence against insects of the order Lepidoptera, Coleoptera, and Hemiptera were evaluated. Furthermore, the strain was evaluated for its biochemical and physiological characteristics. For virulence bioassays, the experiments were conducted under a factorial scheme (2 × 3), with the following factors: (a) fungal inoculation and control without inoculum and (b) types of inocula (blastospores, aerial conidia, and metabolites). The treatments were sprayed on insect species at different stages of development. In summary, it was found that the SBF054 strain endophytically colonized the common bean, with partial recovery from the root tissues of soybean and sunflower plants, 30 days after inoculation; suppressed 86% of Rhizoctonia solani mycelial growth in an in vitro assay; and controlled eggs, nymphs, and Euschistus heros adults. These multifunctional abilities are mainly attributed to the strain's mechanisms of producing metabolites, such as organic acids, soluble nutrients, and hydrolytic enzymes. [ABSTRACT FROM AUTHOR]

Yeast is one of the important symbiotic flora in the insect gut. However, little is known about the gut yeast in Helicoverpa armigera (Lepidoptera: Noctuidae) under various dietary conditions. The composition and function of the intestinal yeast community also remain unclear. In this research, we explored the composition of yeast microorganisms in H. armigera larvae under different feeding environments, including apple, pear, tomato, artificial diet (laboratory feeding), Urtica fissa, Helianthus annuus, and Zinnia elegans (wild environment) using high-throughput sequencing. Results showed that a total of 43 yeast OTU readings were obtained, comprising 33 yeast genera and 42 yeast species. The yeast genera with a total content of more than 5% were Hanseniaspora (36.27%), Moesziomyces (21.47%), Trichosporon (16.20%), Wickerhamomyces (12.96%) and Pichia (6.38%). Hanseniaspora was predominant when fed indoors with fruits, whereas Moesziomyces was only detected in the wild group (Urtica fissa, Helianthus annuus, Zinnia elegans) and the artificial diet group. After transferring the larvae from artificial diet to apple, pear and tomato, the composition of intestinal yeast community changed, mainly reflected in the increased relative abundance of Hanseniaspora and the decreased abundance of Trichosporon. Simultaneously, the results of a diversity index indicated that the intestinal yeast microbial diversity of H. armigera fed on wild plants was higher than that of indoor artificial feeding. PCoA and PERMANOVA analysis concluded that there were significant differences in the gut yeast composition of H. armigera larvae on different diets. Our results confirmed that gut yeast communities of H. armigera can be influenced by host diets and may play an important role in host adaptation. [ABSTRACT FROM AUTHOR]

An extremely important oil crop in the world, Helianthus annuus L. is one of the world's most significant members of the Asteraceae family. The rate and extent of seed germination and agronomic features are consistently affecting by temperature (T) and changes in water potential (ψ). A broad hydrothermal time model with T and ψ components could explain sunflower responses over suboptimal T and ψ. A lab experiment was performed using the HTT model to discover both T and ψ and their interactive effects on sunflower germination and also to figure out the cardinal Ts values. The sunflower seeds were germinated at temperatures (15 °C, 20 °C, 25 °C and 30 °C); each Ts had five constant ψs of 0, 0.3, 0.6, 0.9, and 1.2 MPa via PEG 6000 as osmotic stress inducer. The results revealed that highest germination index was found in seed grown at 20 °C in distilled water (0 MPa) and the lowest at 30 °C with osmotic stress of (− 1.2 MPa). The highest value of germination rate index was found in seed grown at 20 °C in distilled water (0 MPa) and the lowest at 15 °C with an osmotic stress of (− 1.2 MPa). In conclusion, water potential, temperature, and their interactions have a considerable impact on seed germination rate, and other metrics (GI, SVI-I, GRI, GE, SVI-II, and MGT). Seeds sown at 20 °C with zero water potential showed high germination metrics such as GE, GP, GRI, and T50%. The maximum value to TTsub noted at 30 °C in − 0.9 MPa osmotic stress and the minimum value was calculated at 15 °C in − 1.2 MPa osmotic stress. The result of TTsupra recorded highest at 15 °C in controlled group (0 MPa). Moreover, θH was highest at 30 °C in controlled condition (0 MPa) and minimum value was observed at 20 °C under − 1.2 MPa osmotic stress. The value of θHTT were maximum at 30 °C in controlled group (0 MPa) and minimum value was recorded at 15 °C under − 1.2 MPa osmotic potential. The base, optimum and ceiling temperatures for sunflower germination metrics in this experiment were noted 6.8, 20 and 30 °C respectively. [ABSTRACT FROM AUTHOR]

The reason for this examination is today's wide usage of chlorophyll a fluorescence (ChlF) among researchers worldwide to measure photosynthetic efficiency. Although the instructions of the ChlF measuring device clearly emphasize the need for methodology adjustments, depending on the specific plant species, many researchers use the usual 30 min of dark adaptation before measurement. Namely, before any ChlF measurement, it is necessary to determine the specific duration of the leaf adaptation to the conditions of darkness of each plant tissue. Because of the numerous uses of the ChlF measurements, we decided to conduct this research to determine whether the appearance of the curves and parameter values depend on the time of sunflower leaf tissue adaptation to dark conditions. Therefore, this research aimed to examine the optimal adaptation time of sunflower tissue to dark conditions to obtain timely precise measurements and credible appearance of ChlF transient curves as well as accurate parameter values. The research was carried out on the sunflower hybrid Luka with 0, 15, 30, 45, 60, 75 and 90 min of dark adaptation in the vegetative, budding and flowering stages in the field conditions. According to the analyzed transient curves and parameters, it was determined that sunflower leaves should be kept in dark conditions for at least 15 min before the measurement of ChlF, which leads to the complete oxidation of PSII and the electron transport chain prior to a saturating pulse of light. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) is a widely cultivated, fast-growing crop known for its seeds and oil, with substantial ecological and economic importance globally. However, it faces challenges from leaf diseases caused by Alternaria species, which threaten its yield. Three small-spored Alternaria species were isolated from leaf spot and blight symptoms on sunflower in Myanmar. All the species were determined based on morphological characterization and a multi-locus phylogenetic assessment of seven genes, including the internal transcribed spacer of rDNA region (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), RNA polymerase second largest subunit (RPB2), translation elongation factor 1-α (TEF1), Alternaria major allergen gene (Alt a 1), endopolygalacturonase gene (EndoPG), and an anonymous gene region (OPA10-2). The results introduced two new Alternaria species, A. myanmarensis sp. nov. and A. yamethinensis sp. nov., and a known species of A. burnsii, firstly reported from sunflower. [ABSTRACT FROM AUTHOR]

MYBs constitute the second largest transcription factor (TF) superfamily in flowering plants with substantial structural and functional diversity, which have been brought into focus because they affect flower colors by regulating anthocyanin biosynthesis. Up to now, the genomic data of several Chrysanthemum species have been released, which provides us with abundant genomic resources for revealing the evolution of the MYB gene family in Chrysanthemum species. In the present study, comparative analyses of the MYB gene family in six representative species, including C. lavandulifolium, C. seticuspe, C. ×morifolium, Helianthus annuus, Lactuca sativa, and Arabidopsis thaliana, were performed. A total of 1104 MYBs, which were classified into four subfamilies and 35 lineages, were identified in the three Chrysanthemum species (C. lavandulifolium, C. seticuspe, and C. ×morifolium). We found that whole-genome duplication and tandem duplication are the main duplication mechanisms that drove the occurrence of duplicates in CmMYBs (particularly in the R2R3-MYB subfamily) during the evolution of the cultivated chrysanthemums. Sequence structure and selective pressure analyses of the MYB gene family revealed that some of R2R3-MYBs were subjected to positive selection, which are mostly located on the distal telomere segments of the chromosomes and contain motifs 7 and 8. In addition, the gene expression analysis of CmMYBs in different organs and at various capitulum developmental stages of C. ×morifolium indicated that CmMYBS2, CmMYB96, and CmMYB109 might be the negative regulators for anthocyanin biosynthesis. Our results provide the phylogenetic context for research on the genetic and functional evolution of the MYB gene family in Chrysanthemum species and deepen our understanding of the regulatory mechanism of MYB TFs on the flower color of C. ×morifolium. [ABSTRACT FROM AUTHOR]

Angiosperms and bryophytes, though distantly related plant groups, have many similar ecological and economic implications, including medicinal value. Therefore, this study aimed to analyse the phenolic and flavonoids composition and antioxidant and antimicrobial activities of Helianthus annuus L. (Angiosperms-Asteraceae) and another plant, a moss (Bryophyta), Hyophila involuta (Hook.) Jaeg., aerial parts (leaves), prepared in four different extracts (methanol, chloroform, distilled water, and petroleum ether). Phytochemical screening was conducted using standard methods of precipitation and colouration reactions. The Folin-Ciocalteu method was employed to determine the total phenol content, while the Aluminium Chloride Colorimetric method was used for flavonoid content determination. The antioxidant activity was measured through two methods: DPPH and NOSA scavenging activity. The phytochemical screening detected the presence and absence of fixed oils and fats, flavonoids, saponins, terpenoids, tannins, polyphenols, carbohydrates, and glycosides in both plants. The antibacterial and antifungal activity of both plants' methanolic extracts was examined against bacterial and fungal pathogens, i.e., Escherichia coli and Bacillus subtilis and fungal strains, i.e., Fusarium oxysporum and Aspergillus niger. The results were compared to a regular antibiotic disc and negative control that served as a methanol solvent. The methanolic extract of H. annuus has higher total phenol and flavonoid content, as well as antioxidant and antimicrobial activity, than H. involuta. Based on these data, it can be concluded that, while H. annuus is more effective than H. involuta, both distantly related plant species have similar phytochemical profiles and should be included equally in future herbal compositions. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) is an important, substantial global oil crop with robust resilience to drought and salt stresses. The TGA (TGACG motif-binding factor) transcription factors, belonging to the basic region leucine zipper (bZIP) family, have been implicated in orchestrating multiple biological processes. Despite their functional significance, a comprehensive investigation of the TGA family's abiotic stress tolerance in sunflowers remains elusive. In the present study, we identified 14 TGA proteins in the sunflower genome, which were unequally distributed across 17 chromosomes. Employing phylogenetic analysis encompassing 149 TGA members among 13 distinct species, we revealed the evolutionary conservation of TGA proteins across the plant kingdom. Collinearity analysis suggested that both HaTGA01 and HaTGA03 were generated due to HaTGA08 gene duplication. Notably, qRT-PCR analysis demonstrated that HaTGA04, HaTGA05, and HaTGA14 genes were remarkably upregulated under ABA, MeJA, and salt treatments, whereas HaTGA03, HaTGA06, and HaTGA07 were significantly repressed. This study contributes valuable perspectives on the potential roles of the HaTGA gene family under various stress conditions in sunflowers, thereby enhancing our understanding of TGA gene family dynamics and function within this agriculturally significant species. [ABSTRACT FROM AUTHOR]

The quantity and quality of sunflower oil are key factors for the crushing industry. This research presents a comprehensive analysis of the oil quality parameters of seven foreign sunflower hybrids grown in Morocco. Conducted over two consecutive years (2018 and 2019), the study focuses on key traits, including oil content, acidity index, peroxide index, refractive index, color index, total phenolic content, total flavonoid content, and antioxidant activity. Significant variations in most parameters, including color properties, were observed between the two years and among the seven varieties, indicating the influence of genetic and environmental factors. This highlights the importance of understanding the genetic potential of sunflower hybrids and the impact of environmental variables on oil quality. More favorable weather conditions in 2019, compared to 2018, contributed to better oil quality in all the varieties investigated. Overall, four homogeneous groups of hybrid varieties were identified based on oil content and other biochemical parameters. Some of these hybrids, like 'Niagara', had moderate oil content but high polyphenol content, flavonoid content and antioxidant activity, as well as a lower peroxide index, making them potential sources of natural antioxidant compounds as well as dietary supplements. Overall, this research provides sunflower breeders with valuable insights into the development of new high-performing hybrids with enhanced oil quality that could be used to produce functional foods with health benefits. These findings have implications for the use of seed oils from those hybrids in various industries and underscore the importance of further and more in-depth research on sunflower oil quality in the context of climate change. [ABSTRACT FROM AUTHOR]

Background: Arsenic (As) is a highly toxic and carcinogenic pollutant commonly found in soil and water, posing significant risks to human health and plant growth. Objective: The objectives of this study to evaluate morphological, biochemical, and physiological markers, as well as ion homeostasis, to alleviate the toxic effects of As in sunflowers through the exogenous application of salicylic acid (SA), γ-aminobutyric acid (GABA), and their combination. Methods: A pot experiment was conducted using two sunflower genotypes, FH-779 and FH-773, subjected to As stress (60 mg kg−1) to evaluate the effects of SA at 100 mg L−1, GABA at 200 mg L−1, and their combination on growth and related physiological and biochemical attributes under As stress. Results: The study revealed that As toxicity had a detrimental effect on various growth parameters, chlorophyll pigments, relative water content, total proteins, and nutrient uptake in sunflower plants. It also led to increased oxidative stress, as indicated by higher levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2), along with As accumulation in the roots and leaves. However, the application of SA and GABA protected against As-induced damage by enhancing the enzymatic antioxidant defense system. This was achieved through the activation of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities, as well as an increase in osmolytes. They also improved nutrient acquisition and plant growth under As toxicity. Conclusions: We investigated the regulatory roles of SA and GABA in mitigating arsenic-induced phytotoxic effects on sunflower. Our results revealed a significant interaction between SA and GABA in regulating growth, photosynthesis, metabolites, antioxidant defense systems, and nutrient uptake in sunflower under As stress. These findings provide valuable insights into plant defense mechanisms and strategies to enhance stress tolerance in contaminated environments. In the future, SA and GABA could be valuable tools for managing stress in other important crops facing abiotic stress conditions. [ABSTRACT FROM AUTHOR]

This study investigates the impact of soaking, germination, and roasting under various conditions on the phenolic content, antioxidant activities, and fatty acid profile of sunflower seeds of striped and black oil seed varieties. Ferulic acid emerged as the predominant phenolic acid across all samples. The study highlights the influence of different treatments and processing conditions on the levels of phenolic acids and flavonoids. Results revealed that soaking striped seeds for 24 h and roasting black oil seeds for 6 min exhibited the highest total phenolic content (TPC) and total flavonoid content (TFC). Antioxidant activities varied, with striped seeds soaked for 24 h demonstrating the highest ferric-reducing antioxidant power (FRAP) values, while black oil seeds roasted for 6 min exhibited superior 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activity. Oleic acid and linoleic acid were identified as major fatty acids in all processed samples, with striped seeds germinated for 24 h and black oil seeds germinated for 48 h displaying the highest concentrations. Soaking led to a reduction in both unsaturated and saturated fatty acids in both varieties. Roasting further influenced fatty acid concentrations, with a significant increase in striped seeds after 5 and 6 h of roasting, followed by a gradual decrease. Our findings suggest that incorporating appropriate processing methods, such as soaking striped seeds for 24 h and roasting black oil seeds for 6 min, enhances the potential health benefits of sunflower seeds. [ABSTRACT FROM AUTHOR]

Cultivated crops are generally expected to have less abiotic stress tolerance than their wild relatives. However, this assumption is not well supported by empirical literature and may depend on the type of stress and how it is imposed, as well as the measure of tolerance being used. Here, we investigated whether wild and cultivated accessions of Helianthus annuus differed in stress tolerance assessed as proportional decline in biomass due to drought and whether wild and cultivated accessions differed in trait responses to drought and trait associations with tolerance. In a greenhouse study, H. annuus accessions in the two domestication classes (eight cultivated and eight wild accessions) received two treatments: a well‐watered control and a moderate drought implemented as a dry down followed by maintenance at a predetermined soil moisture level with automated irrigation. Treatments were imposed at the seedling stage, and plants were harvested after 2 weeks of treatment. The proportional biomass decline in response to drought was 24% for cultivated H. annuus accessions but was not significant for the wild accessions. Thus, using the metric of proportional biomass decline, the cultivated accessions had less drought tolerance. Among accessions, there was no tradeoff between drought tolerance and vigor assessed as biomass in the control treatment. In a multivariate analysis, wild and cultivated accessions did not differ from each other or in response to drought for a subset of morphological, physiological, and allocational traits. Analyzed individually, traits varied in response to drought in wild and/or cultivated accessions, including declines in specific leaf area, leaf theoretical maximum stomatal conductance (gsmax), and stomatal pore length, but there was no treatment response for stomatal density, succulence, or the ability to osmotically adjust. Focusing on traits associations with tolerance, plasticity in gsmax was the most interesting because its association with tolerance differed by domestication class (although the effects were relatively weak) and thus might contribute to lower tolerance of cultivated sunflower. Our H. annuus results support the expectation that stress tolerance is lower in crops than wild relatives under some conditions. However, determining the key traits that underpin differences in moderate drought tolerance between wild and cultivated H. annuus remains elusive. [ABSTRACT FROM AUTHOR]

Background: Drought severely limits sunflower production especially at the seedling stage. To investigate the response mechanism of sunflowers to drought stress, we utilized two genotypes of sunflower materials with different drought resistances as test materials. The physiological responses were investigated under well-watered (0 h) and drought-stressed conditions (24 h, 48 h, and 72 h). Results: ANOVA revealed the greatest differences in physiological indices between 72 h of drought stress and 0 h of drought stress. Transcriptome analysis was performed after 72 h of drought stress. At 0 h, there were 7482 and 5627 differentially expressed genes (DEGs) in the leaves of K55 and K58, respectively, and 2150 and 2527 DEGs in the roots of K55 and K58, respectively. A total of 870 transcription factors (TFs) were identified among theDEGs, among which the high-abundance TF families included AP2/ERF, MYB, bHLH,and WRKY. Five modules were screened using weighted gene coexpressionnetwork analysis (WGCNA), three and two of which were positively and negatively, respectively, related to physiological traits. KEGG analysis revealedthat under drought stress, "photosynthesis", "carotenoid biosynthesis", "starch and sucrose metabolism", "ribosome", "carotenoid biosynthesis", "starch and sucrose metabolism", "protein phosphorylation" and "phytohormone signaling" are six important metabolic pathways involved in the response of sunflower to drought stress. Cytoscape software was used to visualize the three key modules, and the hub genes were screened. Finally, a total of 99 important candidate genes that may be associated with the drought response in sunflower plants were obtained, and the homology of these genes was compared with that in Arabidopsis thaliana. Conclusions: Taken together, our findings could lead to a better understanding of drought tolerance in sunflowers and facilitate the selection of drought-tolerant sunflower varieties. [ABSTRACT FROM AUTHOR]

Plant protein phosphatase 2C (PP2C) plays vital roles in responding to various stresses, stimulating growth factors, phytohormones, and metabolic activities in many important plant species. However, the PP2C gene family has not been investigated in the economically valuable plant species sunflower (Helianthus annuus L.). This study used comprehensive bioinformatics tools to identify and characterize the PP2C gene family members in the sunflower genome (H. annuus r1.2). Additionally, we analyzed the expression profiles of these genes using RNA-seq data under four different stress conditions in both leaf and root tissues. A total of 121 PP2C genes were identified in the sunflower genome distributed unevenly across the 17 chromosomes, all containing the Type-2C phosphatase domain. HanPP2C genes are divided into 15 subgroups (A-L) based on phylogenetic tree analysis. Analyses of conserved domains, gene structures, and motifs revealed higher structural and functional similarities within various subgroups. Gene duplication and collinearity analysis showed that among the 53 HanPP2C gene pairs, 48 demonstrated segmental duplications under strong purifying selection pressure, with only five gene pairs showing tandem duplications. The abundant segmental duplication was observed compared to tandem duplication, which was the major factor underlying the dispersion of the PP2C gene family in sunflowers. Most HanPP2C proteins were localized in the nucleus, cytoplasm, and chloroplast. Among the 121 HanPP2C genes, we identified 71 miRNAs targeting 86 HanPP2C genes involved in plant developmental processes and response to abiotic stresses. By analyzing cis-elements, we identified 63 cis-regulatory elements in the promoter regions of HanPP2C genes associated with light responsiveness, tissue-specificity, phytohormone, and stress responses. Based on RNA-seq data from two sunflower tissues (leaf and root), 47 HanPP2C genes exhibited varying expression levels in leaf tissue, while 49 HanPP2C genes showed differential expression patterns in root tissue across all stress conditions. Transcriptome profiling revealed that nine HanPP2C genes (HanPP2C12, HanPP2C36, HanPP2C38, HanPP2C47, HanPP2C48, HanPP2C53, HanPP2C54, HanPP2C59, and HanPP2C73) exhibited higher expression in leaf tissue, and five HanPP2C genes (HanPP2C13, HanPP2C47, HanPP2C48, HanPP2C54, and HanPP2C95) showed enhanced expression in root tissue in response to the four stress treatments, compared to the control conditions. These results suggest that these HanPP2C genes may be potential candidates for conferring tolerance to multiple stresses and further detailed characterization to elucidate their functions. From these candidates, 3D structures were predicted for six HanPP2C proteins (HanPP2C47, HanPP2C48, HanPP2C53, HanPP2C54, HanPP2C59, and HanPP2C73), which provided satisfactory models. Our findings provide valuable insights into the PP2C gene family in the sunflower genome, which could play a crucial role in responding to various stresses. This information can be exploited in sunflower breeding programs to develop improved cultivars with increased abiotic stress tolerance. [ABSTRACT FROM AUTHOR]

Safflower is a multipurpose crop with several uses that can offer benefits to rainfed cereal-based cropping systems due to its tolerance to cold, drought, salinity, and its reduced need for agricultural inputs. Safflower requires good weed control for optimum yields because it is a very poor competitor with weeds, especially at the early growth stage, but registered pre-emergence herbicides are not available. This research investigated the effects of several pre-emergence herbicides on weed control and the yield of safflower in central Italy, through two field experiments in 2019 and 2020. Aclonifen, metazachlor, s-metolachlor, propyzamide, and metribuzin were applied as pre-emergence herbicides. The main weeds were the following: Papaver rhoeas L., Conyza canadensis (L.) Cronq., and Ammi majus L. in experiment 1, and wild sunflower (Helianthus annuus L.) in experiment 2. Metazachlor and metribuzin gave the highest phytotoxicity on safflower in both experiments, with values ranging from 48% to 75% and from 30% to 75% (in a scale of 0–100%), respectively, and seem to be not advisable as pre-emergence herbicides. Aclonifen, s-metolachlor, and propyzamide can be considered selective and safe to the safflower, showing the lowest values of phytotoxicity that ranged from 0 to 10%. Metazachlor and s-metolachlor gave the highest total weed control with values of 92% and 97%, respectively. [ABSTRACT FROM AUTHOR]