Search

Leaf vein, an essential part of leaf architecture, plays significant roles in shaping the proper leaf size. To date, the molecular mechanisms governing leaf development including leaf venation patterning remains poorly understood in birch. Here, we performed the genome-wide identification of homeodomain-like (HD-like) superfamily genes using phylogenetic analysis and revealed the functional role of a potential HD-like gene in leaf growth and development using transgenic technology and transcriptomic sequencing. A total of 267 HD-like genes were identified based on Arabidopsis HD-containing transcription factors, which were members of KNOTTED1-like homeobox (KNOX) family, BELL1-like homeobox (BLH) family, Zinc finger-HD (ZHD) family, HD-leucine zipper (HD-Zip) family, Golden2, ARR-B, Psr1 (GARP) family, WUSCHEL-related homeobox (WOX) family, and Myeloblastosis (MYB) and MYB-like family. Further, 41 HD-like genes showing co-expression with marker genes related to leaf vascular tissues exhibited differential expression during primary vein development. Among them, a potential HD-like gene (BpPHD4) of GARP family served as a negative factor in governing leaf size and venation patterning. Compared to non-transgenic plants, BpPHD4 repression transgenic plants showed increased leaf length, leaf width, leaf area, leaf thickness, spongy tissue thickness, stomata number, epidermal cell size, primary vein length, the distance between the secondary veins, and primary vein diameter, which was opposite to those of BpPHD4 overexpression transgenic plants. Meanwhile, reduced expression levels of BpPHD4 could remarkably promote phloem tissue development. Transcriptome analysis of BpPHD4 overexpression transgenic plants showed two candidate genes (Bpev01.c0518.g0018 and Bpev01.c2797.g0002) probably regulated by BpPHD4. To conclude, our findings contribute to a better understanding of HD-like superfamily genes and unravel the role of a potential HD-like gene in genetically controlling leaf size and venation patterning in birch, which provides clues to genetic improvement of woody plants with diverse geometric and topological properties of leaf vascular network. [ABSTRACT FROM AUTHOR]

Exploring the relationship between leaf and xylem growth and nitrogen (N) deposition on tree growth helps us better understand how N deposition affects tree growth, but relevant studies are still limited. We tested if leaf and xylem growth and their relationship were affected by N deposition across multiple stages of leaf development. We studied two dominant tree species (Castanopsis chinensis and Schima superba) in a subtropical forest in South China, monitoring their leaf and xylem growth traits under canopy N addition of 0 (CK) and 50 kg N ha−1 year−1 (CAN) and compared these traits and their relationships across different treatments, periods, and species. We found that CAN significantly increased C. chinensis's leaf carbon (C) content, while the same treatment reduced leaf C content in S. superba. Specific leaf area (SLA), specific leaf weight (SLW), leaf N content, and C:N ratio showed more variation between species and within species across developmental stages than in response to different N addition treatments. Nitrogen addition also significantly increased the xylem width in both species, but the weekly xylem increment before July was notably higher in S. superba than in C. chinensis. Moreover, the leaf C content during early leaf development (ELD) following N addition was significantly and negatively correlated with the start date of xylogenesis in C. chinensis but had no significant effect on the onset of xylogenesis in S. superba. Additionally, regardless of species, SLA in ELD was negatively correlated with xylem width at the end of the early growing season (EW) under CK. However, this relationship became insignificant under CAN, suggesting that N addition alleviated the trade-off between SLA in ELD and EW. These results demonstrated that the relationship between leaf and xylem growth is influenced by both the leaf developmental stage and N availability. Traditional analyses of the leaf–xylem relationship, based solely on mature leaf traits, might oversimplify the effects of N deposition on tree growth. [ABSTRACT FROM AUTHOR]

Background: Disanthus cercidifolius var. longipes is an ancient relic plant unique to China. However, the typical shade-loving plant is largely exposed to the sun, which poses a major challenge to its conservation. Methods: This study explored dynamic changes in primary and secondary metabolites in D. cercidifolius leaves at different stages of development, combining metabolomics and transcriptome analysis to discuss the differentially accumulated metabolites (DAMs) and differentially expressed genes (DEGs). Results: The DAMs and DEGs were enriched in pathways related to photosynthesis, carbon (C) metabolism, anthocyanin synthesis, plant hormone signal transduction, and flavonoid synthesis. At the initial stage of leaf development, many primary metabolites were synthesized in the leaves. Before leaf maturity, many primary metabolites were converted into secondary metabolites. Combined transcriptome and metabolome analysis showed that the metabolites and genes related to anthocyanin synthesis and flavonoid metabolism were upregulated. In contrast, the genes related to C metabolism and C fixation were downregulated. After leaf maturity, photosynthetic capacity increased, total flavonoid content peaked (implying the strongest photoprotection capacity), and the transformation of anthocyanins and flavonoids was weakened. Conclusions: Light intensity indirectly affects the accumulation of the primary and secondary metabolism of D. cercidifolius. With the enhancement of photoprotection, the photosynthetic energy capacity decreases. It is, therefore, inferable that D. cercidifolius has shading properties and achieves a stable nutrient supply during growth and development through these strategies. Thus, D. cercidifolius protection requires a shaded environment. [ABSTRACT FROM AUTHOR]

The polyketide antibiotic 2,4-diacetylphloroglucinol (DAPG) is a phenolic secondary metabolite produced by Pseudomonas spp. that serves as a biocontrol agent. DAPG is known to inhibit root growth and seed germination in plants. However, the effects of DAPG on leaf growth have not been elucidated yet. In this study, we found that applying DAPG at concentration above 30 µM suppresses the development of Arabidopsis leaves. Using an integrated proteomic analysis approach, we investigated the physio-molecular responses of Arabidopsis leaves under 10–100 µM DAPG treatment. Two-dimensional electrophoresis (2-DE)-based proteomic analysis identified 46 differentially expressed spots with at least a twofold change, corresponding to 37 proteins involved in stress and defense, metabolism, photosynthesis, and carbohydrate metabolism processes. Furthermore, we found that the expressions of stress and defense-related proteins were upregulated in response to DAPG, while those of photosynthesis-related proteins were downregulated. Additionally, RT-PCR result showed that the identified DAPG-responsive proteins in the proteomic analysis were similarly regulated at the transcriptional level. Collectively, our findings provide insights into the molecular mechanism of the response to DAPG in Arabidopsis leaves. [ABSTRACT FROM AUTHOR]

To investigate the dynamics of stomata, transpiration, and photosynthesis under varying light intensities and CO2 conditions during leaf development, the light response and CO2 response of stomatal conductance (gsw), transpiration rate (Tr), and net photosynthetic rate (Pn) were observed for rice leaves at different days after leaf emergence (DAE). The results showed that (1) as photosynthetically active radiation (PAR) increased, leaf gsw, Tr, and Pn initially increased rapidly and linearly, followed by a more gradual rise to maximum values, and then either stabilized or showed a declining trend. The maximum gsw, Tr, and Pn were smaller and occurred earlier for old leaves than for young leaves. The gsw, Tr, and Pn all exhibited a linear decreasing trend with increasing DAE, and the rate of decrease slowed down with the reduction in PAR; (2) as the CO2 concentration (Ca) increased, gsw and Tr decreased gradually to a stable minimum value, while Pn increased linearly and slowly up to the maximum and then kept stable or decreased. The gsw, Tr, and Pn values initially kept high and then decreased with the increase of DAE. These results contribute to understanding the dynamics in gsw, Tr, and Pn during rice leaf growth and their response to varied light and CO2 concentration conditions and provide mechanistic support to estimate dynamic evapotranspiration and net ecosystem productivity at field-scale and a larger scale in paddy field ecosystems through the upscaling of leaf-level stomatal conductance, transpiration, and photosynthesis. [ABSTRACT FROM AUTHOR]

Foliar development involves successive phases of cell proliferation and expansion that determine the final leaf size, and is characterized by an early burst of reactive oxygen species generated in the photosynthetic electron transport chain (PETC). Introduction of the alternative PETC acceptor flavodoxin in tobacco chloroplasts led to a reduction in leaf size associated to lower cell expansion, without affecting cell number per leaf. Proteomic analysis showed that the biogenesis of the PETC proceeded stepwise in wild-type leaves, with accumulation of light-harvesting proteins preceding that of electron transport components, which might explain the increased energy and electron transfer to oxygen and reactive oxygen species build-up at this stage. Flavodoxin expression did not affect biogenesis of the PETC but prevented hydroperoxide formation through its function as electron sink. Mature leaves from flavodoxin-expressing plants were shown to contain higher levels of transcripts encoding components of the proteasome, a key negative modulator of organ size. Proteome profiling revealed that this differential accumulation was initiated during expansion and led to increased proteasomal activity, whereas a proteasome inhibitor reverted the flavodoxin-dependent size phenotype. Cells expressing plastid-targeted flavodoxin displayed lower endoreduplication, also associated to decreased organ size. These results provide novel insights into the regulation of leaf growth by chloroplast-generated redox signals, and highlight the potential of alternative electron shuttles to investigate the link(s) between photosynthesis and plant development. [ABSTRACT FROM AUTHOR]

The leaf is a determinate organ with a final size under genetic control. Numerous factors that regulate the final leaf size have been identified in Arabidopsis thaliana ; although most of these factors play their roles during the growth of leaf primordia, much less is known about leaf initiation and its effects on the final leaf size. In this study, we characterized oligocellula6-D (oli6-D), a semidominant mutant of A. thaliana with smaller leaves than the wild type (WT) due to its reduced leaf cell numbers. A time-course analysis showed that oli6-D had approximately 50% fewer leaf cells even immediately after leaf initiation; this difference was maintained throughout leaf development. Next-generation sequencing showed that oli6-D had chromosomal duplications involving 2-kb and 3-Mb regions of chromosomes 2 and 4, respectively. Several duplicated genes examined had approximately 2-fold higher expression levels, and at least one gene acquired a new intron/exon structure due to a chromosome fusion event. oli6-D showed reduced auxin responses in leaf primordia, primary roots and embryos, as well as reduced apical dominance and partial auxin-resistant root growth. CRISPR-associated protein-9-mediated genome editing enabled the removal of a 3-Mb duplicated segment, the largest targeted deletion in plants thus far. As a result, oli6-D restored the WT leaf phenotypes, demonstrating that oli6-D is a gain-of-function mutant. Our results suggest a new regulatory point of leaf size determination that functions at a very early stage of leaf development and is negatively regulated by one or more genes located in the duplicated chromosomal segments. [ABSTRACT FROM AUTHOR]

This study examines the growth patterns, leaf morpho-anatomical traits and physiological characteristics of three ornamental taxa of Alocasia: A. melo, A reginae and Alocasia × morfontanensis 'Bambino'. Using optical and scanning electron microscopy, the research obtained anatomical details of the leaves. Alocasia × morfontanensis 'Bambino' exhibited the highest leaf growth rate among the taxa studied, showing significant leaf number increases from the 8th to the 12th week after planting. Alocasia melo produced 2–3 new basal shoots after 20 weeks, whereas the other two taxa did not produce any. Alocasia melo displayed the greatest relative water content and leaf thickness, while A. reginae showed the highest chlorophyll stability. This study also revealed variations in the adaxial and abaxial leaf color, stomatal width, epidermal thickness, and elemental composition among the taxa involved, with A. melo containing rhodium and high levels of calcium on their leaf surface. These findings contribute to the understanding of the Alocasia leaf morpho-anatomy and growth, which is useful for optimizing Alocasia cultivation and production across diverse ecosystems. [ABSTRACT FROM AUTHOR]

[Objective] Using Chrysanthemum morifolium HETAI, a characteristic medicinal and edible plant in Zhaoqing, Guangdong, as the material, to explore the growth characteristics and nutritional changes of leaves and inflorescences. [Method] The growth of leaves and floral organs from Chrysanthemum morifolium was measured in the field, and corresponding colorimetric methods were used to explore the content changes of effective components. [Result] The Chrysanthemum morifolium HETAI developed from young leaves to mature leaves for about 168 days, with significant morphological changes during the leaf development process. The mature leaves were oval shaped, feathered with shallow or deep cracks, and the leaf edges were round serrated with notches. The growth cycle of flower organs was about 55 days, and it lasted for about 20 days from the initial flowering period to the full-bloom period. The tongue shaped and tubular flower clusters were fully developed; the flower diameter could reach 4.67-4.89 cm. During the development of flower organs, the content of soluble proteins generally showed a downward trend, but the content of total flavonoids and soluble sugars continued to increase, both contents maintain high levels during the development stage of 3140 days. Combined with the growth characteristics of leaves and inflorescences, the initial flowering period and early peak flowering period (31-40 days) were the suitable harvest time for this variety of chrysanthemum. [Conclusion] This study provides a basis for the cultivation standards of advantageous varieties in the characteristic agriculture (Nanyao) science and technology park of Gaoyao District, Guangdong Province [ABSTRACT FROM AUTHOR]

How tissue-level information encoded by fields of regulatory gene activity is translated into the patterns of cell polarity and growth that generate the diverse shapes of different species remains poorly understood. Here, we investigate this problem in the case of leaf shape differences between Arabidopsis thaliana, which has simple leaves, and its relative Cardamine hirsuta that has complex leaves divided into leaflets. We show that patterned expression of the transcription factor CUP-SHAPED COTYLEDON1 in C. hirsuta (ChCUC1) is a key determinant of leaf shape differences between the two species. Through inducible genetic perturbations, time-lapse imaging of growth, and computational modeling, we find that ChCUC1 provides instructive input into auxin-based leaf margin patterning. This input arises via transcriptional regulation of multiple auxin homeostasis components, including direct activation of WAG kinases that are known to regulate the polarity of PIN-FORMED auxin transporters. Thus, we have uncovered a mechanism that bridges biological scales by linking spatially distributed and species-specific transcription factor expression to cell-level polarity and growth, to shape diverse leaf forms. [ABSTRACT FROM AUTHOR]

Aluminum (Al) toxicity in acidic soils can significantly reduce peanut yield. The physiological response of peanut leaves to Al poisoning stress still has not been fully explored. This research examined the influences of Al toxicity on peanut leaves by observing the leaf phenotype, scanning the leaf area and perimeter, and by measuring photosynthetic pigment content, physiological response indices, leaf hormone levels, and mineral element accumulation. Fluorescence quantitative RT–PCR (qPCR) was utilized to determine the relative transcript level of specific genes. The results indicated that Al toxicity hindered peanut leaf development, reducing their biomass, surface area, and perimeter, although the decrease in photosynthetic pigment content was minimal. Al toxicity notably affected the activity of antioxidative enzymes, proline content, and MDA (malondialdehyde) levels in the leaves. Additionally, Al poisoning resulted in the increased accumulation of iron (Fe), potassium (K), and Al in peanut leaves but reduced the levels of calcium (Ca), manganese (Mn), copper (Cu), zinc (Zn), and magnesium (Mg). There were significant changes in the content of hormones and the expression level of genes connected with hormones in peanut leaves. High Al concentrations may activate cellular defense mechanisms, enhancing antioxidative activity to mitigate excess reactive oxygen species (ROS) and affecting hormone-related gene expression, which may impede leaf biomass and development. This research aimed to elucidate the physiological response mechanisms of peanut leaves to Al poisoning stress, providing insights for breeding new varieties resistant to Al poisoning. [ABSTRACT FROM AUTHOR]

Summary Leaf thickness, the leaf growth in the third dimension as quantified by the distance between the adaxial and abaxial surface, is an indispensable aspect of leaf development. The fitness of a plant is strongly influenced by leaf thickness via modulation of major physiological processes, including photosynthesis and water use efficiency. The cellular basis of leaf thickness by alterations in either cell size or the number of cell layers is envisaged using Arabidopsis leaf thickness mutants, such as angustifolia (an) and rotundifolia (rot). Environmental factors coordinate with endogenous signaling mechanisms to exhibit leaf thickness plasticity. Plants growing in different ecological and environmental regimes show different leaf thickness attributes. However, genetic and molecular understandings of leaf thickness regulation remain largely limited. In this review, we highlight how cellular growth is transposed to fine‐tune the leaf thickness via the integration of potential cues and molecular players. We further discuss the physiological significance of leaf thickness plasticity to the environmental cues that might serve as ecological adaptation enabling the plants to withstand future climatic conditions. Taken together, we seek to bridge the genetics and molecular biology of leaf thickness to its physiological significance so that leaf thickness can be systemically targeted in crop improvement programs. [ABSTRACT FROM AUTHOR]

Knowledge of the function of growth-regulating factors (GRFs) in sugarcane (Saccharum officinarum and S. spontaneum) growth and development could assist breeders in selecting desirable plant architectures. However, limited information about GRFs is available in Saccharum due to their polyploidy. In this study, 22 GRFs were identified in the two species and their conserved domains, gene structures, chromosome location, and synteny were characterized. GRF7 expression varied among tissues and responded to diurnal rhythm. SsGRF7-YFPwas localized preferentially in the nucleus and appears to act as a transcriptional cofactor. SsGRF7positively regulated the size and lengthof rice leaves, possibly by regulating cell size and plant hormones. Of seven potential transcription factors binding to the SsGRF7 promoter in S. spontaneum, four showed positive expression patterns, and two showed negative expression patterns relative to SsGRF7. [ABSTRACT FROM AUTHOR]

C4 photosynthesis outperforms C3 photosynthesis in natural ecosystems by maintaining a high photosynthetic rate and affording higher water-use and nitrogen-use efficiencies. C4 plants can survive in environments with poor living conditions, such as high temperatures and arid regions, and will be crucial to ecological and agricultural security in the face of global climate change in the future. However, the genetic architecture of C4 photosynthesis remains largely unclear, especially the genetic regulation of C4 Kranz anatomy. Haloxylon ammodendron is an important afforestation tree species and a valuable C4 wood plant in the desert region. The unique characteristic of H. ammodendron is that, during the seedling stage, it utilizes C3 photosynthesis, while in mature assimilating shoots (maAS), it switches to the C4 pathway. This makes an exceptional opportunity for studying the development of the C4 Kranz anatomy and metabolic pathways within individual plants (identical genome). To provide broader insight into the regulation of Kranz anatomy and non-Kranz leaves of the C4 plant H. ammodendron , carbon isotope values, anatomical sections and transcriptome analyses were used to better understand the molecular and cellular processes related to the development of C4 Kranz anatomy. This study revealed that H. ammodendron conducts C3 in the cotyledon before it switches to C4 in AS. However, the switching requires a developmental process. Stable carbon isotope discrimination measurements on three different developmental stages showed that young AS have a C3-like δ13C even though C4 Kranz anatomy is found, which is inconsistent with the anatomical findings. A C4-like δ13C can be measured in AS until they are mature. The expression analysis of C4 key genes also showed that the maAS exhibited higher expression than the young AS. In addition, many genes that may be related to the development of Kranz anatomy were screened. Comparison of gene expression patterns with respect to anatomy during leaf ontogeny provided insight into the genetic features of Kranz anatomy. This study helps with our understanding of the development of Kranz anatomy and provides future directions for studies on key C4 regulatory genes. [ABSTRACT FROM AUTHOR]

Background and aims: Hakea prostrata (Proteaceae) is a highly phosphorus-use-efficient plant native to southwest Australia. It maintains a high photosynthetic rate at low leaf phosphorus (P) and exhibits delayed leaf greening, a convergent adaptation that increases nutrient-use efficiency. This study aimed to provide broad physiological and gene expression profiles across leaf development, uncovering pathways leading from young leaves as nutrient sinks to mature leaves as low-nutrient, energy-transducing sources. Methods: To explore gene expression underlying delayed greening, we analysed a de novo transcriptome for H. prostrata across five stages of leaf development. Photosynthesis and respiration rates, and foliar pigment, P and nitrogen (N) concentrations were determined, including the division of P into five biochemical fractions. Key results: Transcripts encoding functions associated with leaf structure generally decreased in abundance across leaf development, concomitant with decreases in foliar concentrations of 85% for anthocyanins, 90% for P and 70% for N. The expression of genes associated with photosynthetic function increased during or after leaf expansion, in parallel with increases in photosynthetic pigments and activity, much later in leaf development than in species that do not have delayed greening. As leaves developed, transcript abundance for cytosolic and mitochondrial ribosomal proteins generally declined, whilst transcripts for chloroplast ribosomal proteins increased. Conclusions: There was a much longer temporal separation of leaf cell growth from chloroplast development in H. prostrata than is found in species that lack delayed greening. Transcriptome-guided analysis of leaf development in H. prostrata provided insight into delayed greening as a nutrient-saving strategy in severely phosphorus-impoverished landscapes. [ABSTRACT FROM AUTHOR]

There are limited studies on the cytology of bamboo leaf development from primordium to maturity. This study delves into the leaf morphological characteristics and growth patterns of Sasaella kogasensis 'Aureostriatus' and provides a three-dimensional anatomical analysis of cell division, expansion, and degradation. Leaves on the same branch develop bottom-up, while individual leaves develop the other way around. Like bamboo shoots and culms, the leaves follow a "slow–fast–slow" growth pattern, with longitudinal growth being predominant during their development. The growth zones of individual leaves included division, elongation, and maturation zones based on the distribution of growth space. By measuring 13,303 epidermal long cells and 3293 mesophyll cells in longitudinal sections of rapidly elongating leaves, we observed that in the rapid elongation phase (S4–S5), the division zone was located in the 1–2 cm segment at the bottom of the leaf blade and maintained a constant size, continuously providing new cells for leaf elongation, whereas in the late rapid elongation phase (S6), when the length of the leaf blade was approaching that of a mature leaf, its cells at the bottom of the blade no longer divided and were replaced by the ability to elongate. Furthermore, to gain an insight into the dynamic changes in the growth of the S. kogasensis 'Aureostriatus' leaves in the lateral and periclinal directions, the width and thickness of 1459 epidermal and 2719 mesophyll cells were counted in the mid-cross section of leaves at different developmental stages. The results showed that during the early stages of development (S1–S3), young leaves maintained vigorous division in the lateral direction, while periplasmic division gradually expanded from the bottom to the top of the leaf blade and the number of cell layers stabilized at S4. The meristematic tissues on both sides of the leaf were still able to divide at S4 but the frequency of the division gradually decreased, while cell division and expansion occurred simultaneously between the veins. At S6, the cells at the leaf margins and between the veins were completely differentiated and the width of the leaf blade no longer expanded. These findings revealed changes in cell growth anisotropically during the leaf development of S. kogasensis 'Aureostriatus' and demonstrated that leaf elongation was closely related to the longitudinal expansion of epidermal cells and proliferative growth of mesophyll cells, whereas the cell division of meristematic tissues and expansion of post-divisional cells contributed to the increases in blade width and thickness. The presented framework will facilitate a further exploration of the molecular regulatory mechanisms of leaf development in S. kogasensis 'Aureostriatus' and provide relevant information for developmental and taxonomic studies of bamboo plants. [ABSTRACT FROM AUTHOR]

Environmental prejudices progressively lead to the ban of dwarfing molecules in agriculture, and alternatives are urgently required. Mechanical stimulation (MS) is a promising, eco-friendly, and economical technique, but some responses to mechanical stimulation vary from one plant species to another. Additionally, as more frequent and violent wind episodes are forecasted under global climate change, knowledge of plant responses to stimuli mimicking wind sways is decisive for agriculture. However, little is known about plant mechanosensitive responses after long-term, recurrent MS. Here, the effects of 3-week, recurrent, symmetrical bendings (1 or 12 per day) in Hydrangea macrophylla stems are examined. Bendings repressed internode elongation and leaf area development, whereas the diametrical growth of the basal internode is increased. Responses were dose-dependent, and no desensitization was observed during the 3 weeks of treatment. MS was almost as efficient as daminozide for plant dwarfing, and it improved stem robustness. Histological and molecular responses to MS were spatially monitored and were concordant with ongoing primary or secondary growth in the internodes. Our molecular data provide the first knowledge on the molecular paths controlled by mechanical loads in Hydrangea and revealed for the first time the involvement of XYP1 in thigmomorphogenetic responses. MS still had a transcriptional impact 48 h after the last bending session, promoting the expression of XYP1, FLA11, and CAD1 while repressing the expression of EXP3 and XTH33 homologs in accordance with xylogenesis, cell wall thickening, and lignin deposition in the xylem of basal internodes. In upper elongating internodes, repression of XYP1, CAD1, SAMS1, and CDC23 homologs is correlated with ongoing primary, even though stunted, growth. For producers, our findings highlight the potential of MS as a sustainable and economical option for controlling plant compactness in Hydrangea and show valuable reinforcement of stem strength. [ABSTRACT FROM AUTHOR]

The peanut is an important worldwide cash‐crop for edible oil and protein. However, the kinetic mechanisms that determine gene expression and chromatin accessibility during leaf development in peanut represented allotetraploid leguminous crops are poorly understood at single‐cell resolution. Here, a single‐nucleus atlas of peanut leaves is developed by simultaneously profiling the transcriptome and chromatin accessibility in the same individual‐cell using fluorescence‐activated sorted single‐nuclei. In total, 5930 cells with 50 890 expressed genes are classified into 18 cell‐clusters, and 5315 chromatin fragments are enriched with 26 083 target genes in the chromatin accessible landscape. The developmental trajectory analysis reveals the involvement of the ethylene‐AP2 module in leaf cell differentiation, and cell‐cycle analysis demonstrated that genome replication featured in distinct cell‐types with circadian rhythms transcription factors (TFs). Furthermore, dual‐omics illustrates that the fatty acid pathway modulates epidermal‐guard cells differentiation and providescritical TFs interaction networks for understanding mesophyll development, and the cytokinin module (LHY/LOG) that regulates vascular growth. Additionally, an AT‐hook protein AhAHL11 is identified that promotes leaf area expansion by modulating the auxin content increase. In summary, the simultaneous profiling of transcription and chromatin accessibility landscapes using snRNA/ATAC‐seq provides novel biological insights into the dynamic processes of peanut leaf cell development at the cellular level. [ABSTRACT FROM AUTHOR]

Ensuring the technical and technological possibility of regularly obtaining fresh, high-quality plant production in Antarctic stations is an urgent task of our time. This work is devoted to studying the growth and development of leaf vegetable crops and the main quality indicators of their edible parts when grown in the phytotechnical complex greenhouses at the "Vostok" Antarctic station and at the agrobiopolygon of the Agrophysical Research Institute (AFI). The plants, belonging to 13 varieties of 9 types of leaf vegetable crops (arugula, garden cress, cabbage, mustard, leaf radish, leaf lettuce, amaranth, dill, parsley leaf), were studied during five growing seasons at the "Vostok" station and at the AFI agrobiopolygon under controlled conditions (control). The experimental data obtained demonstrate the high productivity of the phytotechnical complex for most of the investigated crops per unit of useful area, with lower costs of electricity and water consumption per unit of production compared with a number of greenhouses at foreign Antarctic stations and greenhouse complexes with controlled conditions located on other continents. Lettuce crops were the most adapted to the growing conditions at the Antarctic station "Vostok". They did not differ in their evaluated characteristics from the control. All other investigated crops, while not differing in their development rate and quality, had statistically significant (16–61%) decreases in their yield per 1 m2 per year. This may demonstrate the difference in the "genotype–environment" interaction in plants grown at the Antarctic station and AFI agrobiopolygon, probably due to the different barometric pressure and partial pressure of oxygen at the two locations. The positive psychological effects of the greenhouses were identified along with nutritional and other qualities of the plants. [ABSTRACT FROM AUTHOR]

Invasive Japanese knotweed is one of Poland's most aggressive and difficult-to-control species. New methods of control are of utmost importance. This study aimed to analyze young knotweed offshoots' regeneration and physiological condition after treatment of their rhizomes with microwaves of high frequency. The fresh rhizomes were microwaved in the laboratory once for different times (from 5 to 60 s, interval 5 s). Next, in the greenhouse, the growth of offshoots and their biochemical state (spectrophotometry of leaves) were recorded in three measurement series. It was shown that the microwave treatment for 35 s directly destroys knotweed rhizomes of a diameter of 1–3 cm, so it does not produce new offsprings. The treatment times from 5–25 s delay offspring regeneration and growth and development of leaves. The leaves initiate the mechanisms of protection against microwave stress in offshoots grown from the rhizomes exposed to microwaves for 10 s (increase in the anthocyanin index) and the 5 or 20 s treatments (higher values of the photochemical reflectance index). Based on the effective dose (ED50) analysis, the threshold of harmful effects of microwaves on the growth and development of Reynoutria japonica rhizomes was assumed to be 17–19 s. [ABSTRACT FROM AUTHOR]

Background and Aims Plasticity of leaf growth and photosynthesis is an important strategy of plants to adapt to shading stress; however, their strategy of leaf development to achieve a simultaneous increase in leaf area and photosynthesis under shading remains unknown. Methods In the present study, a pot experiment was conducted using three rapeseed genotypes of Huayouza 50 (HYZ50), Zhongshuang 11 (ZS11) and Huayouza 62 (HYZ62), and the responses of plant growth, leaf morphoanatomical traits, cell wall composition and photosynthesis to shading were investigated. Key Results Shading significantly increased leaf area per plant (LA plant) in all genotypes, but the increase in HYZ62 was greater than that in HYZ50 and ZS11. The greater increment of LA plant in HYZ62 was related to the larger decrease in leaf mass per area (LMA) and leaf density (LD), which were in turn related to less densely packed mesophyll cells and thinner cell walls (T cw). Moreover, shading significantly increased photosynthesis in HYZ62 but significantly decreased it in HYZ50. The enhanced photosynthesis in HYZ62 was related to increased mesophyll conductance (g m) due primarily to thinner cell walls. Conclusions The data presented indicate that the different plasticity of mesophyll cell density, cell wall thickness and cell wall composition in response to shading can dramatically affect leaf growth and photosynthesis. [ABSTRACT FROM AUTHOR]

Summary: Plants interact with arbuscular mycorrhizal fungi (AMF) and in doing so, change transcript levels of many miRNAs and their targets. However, the identity of an Argonaute (AGO) that modulates this interaction remains unknown, including in Nicotiana attenuata.We examined how the silencing of NaAGO1/2/4/7/and 10 by RNAi influenced plant‐competitive ability under low‐P conditions when they interact with AMF. Furthermore, the roles of seven miRNAs, predicted to regulate signaling and phosphate homeostasis, were evaluated by transient overexpression.Only NaAGO7 silencing by RNAi (irAGO7) significantly reduced the competitive ability under P‐limited conditions, without changes in leaf or root development, or juvenile‐to‐adult phase transitions. In plants growing competitively in the glasshouse, irAGO7 roots were over‐colonized with AMF, but they accumulated significantly less phosphate and the expression of their AMF‐specific transporters was deregulated. Furthermore, the AMF‐induced miRNA levels were inversely regulated with the abundance of their target transcripts. miRNA overexpression consistently decreased plant fitness, with four of seven‐tested miRNAs reducing mycorrhization rates, and two increasing mycorrhization rates. Overexpression of Na‐miR473 and Na‐miRNA‐PN59 downregulated targets in GA, ethylene, and fatty acid metabolism pathways.We infer that AGO7 optimizes competitive ability and colonization by regulating miRNA levels and signaling pathways during a plant's interaction with AMF. [ABSTRACT FROM AUTHOR]

Secondary metabolites in Cyclocarya paliurus (Batalin) Iljinsk. leaves are beneficial for human health. The synthesis and accumulation of secondary metabolites form a complex process that is influenced by the trade-off between primary and secondary metabolism and by the biosynthetic pathways themselves. In this study, we explored the relationship between secondary metabolite accumulation and the activity of metabolic networks in leaves of C. paliurus. Leaves at three different growth stages were subjected to transcriptomic and non-targeted metabolomic analyses. The results revealed that nitrogen assimilation increased and carbon assimilation decreased as leaves matured, and the patterns of secondary metabolite accumulation and gene expression differed among the leaves at different growth stages. Mature green leaves had higher nitrogen assimilation and lower carbon assimilation, which were correlated with variations in secondary metabolite accumulation. As a major source of carbon and nitrogen, glutamine accumulated in the mature green leaves of C. paliurus. The accumulation of glutamine inhibited phenylalanine biosynthesis by modulating the pentose phosphate pathway but promoted acetyl-CoA biosynthesis through the tricarboxylic acid cycle. These changes led to decreased flavonoid contents and increased triterpenoid contents in mature leaves. These metabolomic and transcriptomic data reveal the differential expression of metabolic regulatory networks during three stages of leaf development and highlight the trade-off between primary and secondary metabolism. Our results provide a comprehensive picture of the metabolic pathways that are active in the leaves of C. paliurus at different growth stages. [ABSTRACT FROM AUTHOR]

The establishment of crop growth models enables the simulation of the impacts of environmental changes on crop growth, providing theoretical guidance for exploring the relationship between environmental factors and crop growth. The model used the growth cycle (GC) as the simulation time step and was built upon four submodels: topology, photosynthesis, biomass allocation, and geometric morphology. It was quantitatively utilized the concept of effective accumulated temperature (EAT) and parameters such as sink and expansion rate were used to explain the allometric growth relationships among different organs. The R2 values for the geometric morphological parameters such as leaf length, leaf width, leaf area, and internode volume ranged from 0.78 to 0.94, while the F-values for the regression equations ranged from 1533.53 to 13949.51. The R2 values for simulating leaf, internode, and earhead biomass were 0.62-0.94, 0.74-0.97, and 0.98, respectively, with RMSE values ranging from 0.02 to 0.13 g for leaf biomass, 0.03 to 0.13 g for internode biomass, and 1.71 g for earhead biomass. The results indicated that the model exhibited good performance and reliability in simulating the growth and development of leaves, internodes, and earheads. This provides a solid foundation for the development of a millet model with functional-structural feedback. [ABSTRACT FROM AUTHOR]

The Flowering locus T (FT) gene encodes the florigen protein, which primarily regulates the flowering time in plants. Recent studies have shown that FT genes also significantly affect plant growth and development. The FT gene overexpression in plants promotes flowering and suppresses leaf and stem development. This study aimed to conduct a transcriptome analysis to investigate the multiple effects of Jatropha curcas L. homolog (JcFT) overexpression on leaf growth in tobacco plants. The findings revealed that JcFT overexpression affected various biological processes during leaf development, including plant hormone levels and signal transduction, lipid oxidation metabolism, terpenoid metabolism, and the jasmonic-acid-mediated signaling pathway. These results suggested that the effects of FT overexpression in plants were complex and multifaceted, and the combination of these factors might contribute to a reduction in the leaf size. This study comprehensively analyzed the effects of JcFT on leaf development at the transcriptome level and provided new insights into the function of FT and its homologous genes. [ABSTRACT FROM AUTHOR]

Although the temporary presence of ribonucleotides in DNA is normal, their persistence represents a form of DNA damage. Here, we assess such damage and damage defense to DNA in plastids and mitochondria of maize. Shoot development proceeds from meristematic, non-pigmented cells containing proplastids and promitochondria at the leaf base to non-dividing green cells in the leaf blade containing mature organelles. The organellar DNAs (orgDNAs) become fragmented during this transition. Previously, orgDNA damage and damage defense of two types, oxidative and glycation, was described in maize, and now a third type, ribonucleotide damage, is reported. We hypothesized that ribonucleotide damage changes during leaf development and could contribute to the demise of orgDNAs. The levels of ribonucleotides and R-loops in orgDNAs and of RNase H proteins in organelles were measured throughout leaf development and in leaves grown in light and dark conditions. The data reveal that ribonucleotide damage to orgDNAs increased by about 2- to 5-fold during normal maize development from basal meristem to green leaf and when leaves were grown in normal light conditions compared to in the dark. During this developmental transition, the levels of the major agent of defense, RNase H, declined. The decline in organellar genome integrity during maize development may be attributed to oxidative, glycation, and ribonucleotide damages that are not repaired. [ABSTRACT FROM AUTHOR]

The leaf is the main site of photosynthesis and is an important component in shaping the ideal rice plant architecture. Research on leaf morphology and development will lay the foundation for high-yield rice breeding. In this study, we isolated and identified a novel curling leaf mutant, designated curling leaf 1 (cl1). The cl1 mutant exhibited an inward curling phenotype because of the defective development of sclerenchymatous cells on the abaxial side. Meanwhile, the cl1 mutant showed significant reductions in grain yield and thousand-grain weight due to abnormal leaf development. Through map-based cloning, we identified the CL1 gene, which encodes a MYB transcription factor that is highly expressed in leaves. Subcellular localization studies confirmed its typical nuclear localization. Transcriptome analysis revealed a significant differential expression of the genes involved in photosynthesis, leaf morphology, yield formation, and hormone metabolism in the cl1 mutant. Yeast two-hybrid assays demonstrated that CL1 interacts with alpha-tubulin protein SRS5 and AP2/ERF protein MFS. These findings provide theoretical foundations for further elucidating the mechanisms of CL1 in regulating leaf morphology and offer genetic resources for practical applications in high-yield rice breeding. [ABSTRACT FROM AUTHOR]

C3 and C4 grasses directly and indirectly provide the vast majority of calories to the human diet, yet our understanding of the molecular mechanisms driving photosynthetic productivity in grasses is largely unexplored. Ground meristem cells divide to form mesophyll or vascular initial cells early in leaf development in C3 and C4 grasses. Here we define a genetic circuit composed of SHORT ROOT (SHR), INDETERMINATE DOMAIN (IDD), and PIN-FORMED (PIN) family members that specifies vascular identify and ground cell proliferation in leaves of both C3 and C4 grasses. Ectopic expression and loss-of-function mutant studies of SHR paralogs in the C3 plant Oryza sativa (rice) and the C4 plant Setaria viridis (green millet) revealed the roles of these genes in both minor vein formation and ground cell differentiation. Genetic and in vitro studies further suggested that SHR regulates this process through its interactions with IDD12 and 13. We also revealed direct interactions of these IDD proteins with a putative regulatory element within the auxin transporter gene PIN5c. Collectively, these findings indicate that a SHR–IDD regulatory circuit mediates auxin transport by negatively regulating PIN expression to modulate minor vein patterning in the grasses. A SHORT ROOT–INTERMEDIATE DOMAIN regulatory circuit modulates auxin transport by negatively regulating PIN-FORMED expression to regulate minor vein patterning in grasses. [ABSTRACT FROM AUTHOR]

Plants contain three NADPH‐thioredoxin reductases (NTR) located in the cytosol/mitochondria (NTRA/B) and the plastid (NTRC) with important metabolic functions. However, mutants deficient in all NTRs remained to be investigated. Here, we generated and characterised the triple Arabidopsis ntrabc mutant alongside with ntrc single and ntrab double mutants under different environmental conditions. Both ntrc and ntrabc mutants showed reduced growth and substantial metabolic alterations, especially in sink leaves and under high CO2 (HC), as compared to the wild type. However, ntrabc showed higher effective quantum yield of PSII under both constant and fluctuating light conditions, altered redox states of NADH/NAD+ and glutathione (GSH/GSSG) and lower potential quantum yield of PSII in sink leaves in ambient but not high CO2 concentrations, as compared to ntrc, suggesting a functional interaction between chloroplastic and extra‐chloroplastic NTRs in photosynthesis regulation depending on leaf development and environmental conditions. Our results unveil a previously unknown role of the NTR system in regulating sink leaf metabolism and plant acclimation to HC, while it is not affecting full plant development, indicating that the lack of the NTR system can be compensated, at least to some extent, by other redox mechanisms. Summary Statement: We unveil that NTRC is crucial for sink leaf metabolism and plant acclimation to high CO2. Although Arabidopsis plants lacking all NADPH‐thioredoxin reductases (NTRs) have severely reduced growth, they produced viable seeds, indicating that NTRs are not essential for plant development and compensated by other redox mechanisms. [ABSTRACT FROM AUTHOR]

Plants contain three NADPH‐thioredoxin reductases (NTR) located in the cytosol/mitochondria (NTRA/B) and the plastid (NTRC) with important metabolic functions. However, mutants deficient in all NTRs remained to be investigated. Here, we generated and characterised the triple Arabidopsis ntrabc mutant alongside with ntrc single and ntrab double mutants under different environmental conditions. Both ntrc and ntrabc mutants showed reduced growth and substantial metabolic alterations, especially in sink leaves and under high CO2 (HC), as compared to the wild type. However, ntrabc showed higher effective quantum yield of PSII under both constant and fluctuating light conditions, altered redox states of NADH/NAD+ and glutathione (GSH/GSSG) and lower potential quantum yield of PSII in sink leaves in ambient but not high CO2 concentrations, as compared to ntrc, suggesting a functional interaction between chloroplastic and extra‐chloroplastic NTRs in photosynthesis regulation depending on leaf development and environmental conditions. Our results unveil a previously unknown role of the NTR system in regulating sink leaf metabolism and plant acclimation to HC, while it is not affecting full plant development, indicating that the lack of the NTR system can be compensated, at least to some extent, by other redox mechanisms. Summary Statement: We unveil that NTRC is crucial for sink leaf metabolism and plant acclimation to high CO2. Although Arabidopsis plants lacking all NADPH‐thioredoxin reductases (NTRs) have severely reduced growth, they produced viable seeds, indicating that NTRs are not essential for plant development and compensated by other redox mechanisms. [ABSTRACT FROM AUTHOR]

TIFYs are plant-specific transcription factors that contain the TIFY structural domain and play an important role in plant leaf growth and development. However, the role played by TIFY in E. ferox (Euryale ferox Salisb.) leaf development has not been investigated. In this study, 23 TIFY genes were identified in E. ferox. Phylogenetic analyses of the TIFY genes showed clustering into three groups (JAZ, ZIM, and PPD). The TIFY domain was shown to be conserved. JAZ was mainly expanded via wholegenome triplication (WGT) in E. ferox. Based on analyses of the TIFY genes in nine species, we found that JAZ has a closer relationship with PPD, in addition to appearing the most recently and expanding most rapidly, leading to the rapid expansion of TIFYs in Nymphaeaceae. In addition, their different evolution types were discovered. Different gene expressions showed the distinct and corresponsive expression patterns of the EfTIFYs in different stages of tissue and leaf development. Finally, The qPCR analysis revealed that the expression of EfTIFY7.2 and EfTIFY10.1 showed an upward trend and high expression throughout leaf development. Further co-expression analysis indicated that EfTIFY7.2 might be more important for the development of E. ferox leaves. This information will be valuable when exploring the molecular mechanisms of EfTIFYs in plants. [ABSTRACT FROM AUTHOR]

The endosomal sorting complex required for transport (ESCRT) is highly conserved in eukaryotic cells and plays an essential role in the biogenesis of multivesicular bodies and cargo degradation to the plant vacuole or lysosomes. Although ESCRT components affect a variety of plant growth and development processes, their impact on leaf development is rarely reported. Here, we found that OsSNF7.2, an ESCRT‐III component, controls leaf rolling in rice (Oryza sativa). The Ossnf7.2 mutant rolled leaf 17 (rl17) has adaxially rolled leaves due to the decreased number and size of the bulliform cells. OsSNF7.2 is expressed ubiquitously in all tissues, and its protein is localized in the endosomal compartments. OsSNF7.2 homologs, including OsSNF7, OsSNF7.3, and OsSNF7.4, can physically interact with OsSNF7.2, but their single mutation did not result in leaf rolling. Other ESCRT complex subunits, namely OsVPS20, OsVPS24, and OsBRO1, also interact with OsSNF7.2. Further assays revealed that OsSNF7.2 interacts with OsYUC8 and aids its vacuolar degradation. Both Osyuc8 and rl17 Osyuc8 showed rolled leaves, indicating that OsYUC8 and OsSNF7.2 function in the same pathway, conferring leaf development. This study reveals a new biological function for the ESCRT‐III components, and provides new insights into the molecular mechanisms underlying leaf rolling. [ABSTRACT FROM AUTHOR]

Phalaenopsis orchids are highly economical ornamental potted plants. Controlling their production schedule requires information on the leaf development characteristics of the orchids. Phalaenopsis leaves affect the plant's photosynthesis, respiration, and transpiration. The leaf growth conditions can serve as a development index for greenhouse management. The use of the growth characteristics of Phalaenopsis leaves as the basis for greenhouse cultivation and management needs to be studied. The allometry of Phalaenopsis leaves is worth studying. The goal of this research was to investigate the allometry of Phalaenopsis leaves and develop prediction models of the total leaf area. Then, these total leaf area models were developed and validated. In this study, five Phalaenopsis varieties (amabilis, Sin-Yuan beauty, Ruey Lish beauty, Ishin KHM1095, and Sogo F1091) were selected. Each sample had five mature leaves. The lengths, widths, and areas of the sequential leaves were measured, and then the length ratios, width ratios, and area ratios were calculated. The top and bottom models were used to calculate the total leaf areas. The results indicate that no significant differences could be found in the length ratios, width ratios, and area ratios of the sequential leaves from the same variety. However, significant differences were found in these leaf characteristics between different varieties. The observation of leaf growth characteristics can be used to provide useful information for Phalaenopsis management. Comparing the predictive criteria of the two models, the top model had a better predictive ability than the bottom model. From a practical viewpoint, measuring the top leaf area is easier than measuring the bottom leaf area in a greenhouse operation. Comparing the effects of the sample numbers on the predictive ability of the model, the sample number of 30 was sufficient to ensure the accuracy of the total leaf area measurements. We provide an easy and accurate method to measure the total leaf area of Phalaenopsis. The calculated values of total leaf areas can be incorporated into decision models for smart management. [ABSTRACT FROM AUTHOR]

Abelmoschus manihot L. (A. manihot) has received more and more attention due to its potential edible and medicinal value. It shows higher yield and related fine agronomic traits suitable for disadvantaged areas and low-input planting. However, a systemic description of the phenological growth stages of A. manihot, an alternative, multipurpose crop of worldwide interest, does not exist. This study aims to detail the phenological growth stages of A. manihot based on the BBCH scale. Nine principal growth stages were described from seed germination to senescence, along with 69 secondary growth stages, including germination, leaf development, formation of side shoots, primary stem elongation, inflorescence emergence, flowering, fruit development, maturation of fruit and seed, and senescence. However, the morphology and structure of A. manihot become complex with growth, and some growth stages, like inflorescence development, flowering, fruit development, and fruit maturation, overlap totally or partially with each other. Thus, the three-digit scale is considered necessary for a complementary description of these growth stages and illustrations for clarification. Moreover, the unique morphology and structure features of the pistil, stamen, and ovary and the development process of fruits and seeds were described in detail at different stages. The basic and extended BBCH scales will add new information on defining and identifying A. manihot phenological growth stages. They will help farmers efficiently schedule and manage A. manihot cultivation and improve knowledge dissemination among growers and researchers. [ABSTRACT FROM AUTHOR]

Plant growth and development are correlated with many aspects, including phytohormones, which have specific functions. However, the mechanism underlying the process has not been well elucidated. Gibberellins (GAs) play fundamental roles in almost every aspect of plant growth and development, including cell elongation, leaf expansion, leaf senescence, seed germination, and leafy head formation. The central genes involved in GA biosynthesis include GA20 oxidase genes (GA20oxs), GA3oxs, and GA2oxs, which correlate with bioactive GAs. The GA content and GA biosynthesis genes are affected by light, carbon availability, stresses, phytohormone crosstalk, and transcription factors (TFs) as well. However, GA is the main hormone associated with BR, ABA, SA, JA, cytokinin, and auxin, regulating a wide range of growth and developmental processes. DELLA proteins act as plant growth suppressors by inhibiting the elongation and proliferation of cells. GAs induce DELLA repressor protein degradation during the GA biosynthesis process to control several critical developmental processes by interacting with F-box, PIFS, ROS, SCLl3, and other proteins. Bioactive GA levels are inversely related to DELLA proteins, and a lack of DELLA function consequently activates GA responses. In this review, we summarized the diverse roles of GAs in plant development stages, with a focus on GA biosynthesis and signal transduction, to develop new insight and an understanding of the mechanisms underlying plant development. [ABSTRACT FROM AUTHOR]

Adaptability of the Swiss chard to the tropical climate opens opportunity to grow this leafy vegetable all year around. Colorful petiole and leaf blade of this vegetable have attracted urban community to grow them. Objectives of this research were to study the morphological and growth characteristics of the Swiss chard, especially leaf growth rate, time to reach full size, and non-destructive measurement of the leaf area. The Swiss chards used were red, pink, and yellow petiole cultivars. The plants were cultivated using the floating culture system. Relative leaf elongation and widening rates were higher at early leaf development, i.e. soon after the leaf blade was unfolded. Then, the rates were gradually declined and completely halted at about 12 days. In this study, combination of the zero-intercept linear model and the length × width (LW) as predictor were accurate for estimation leaf area (LA) of the red (R² =0.981), pink (R² =0.975), and yellow (R² =0.980) petiole cultivars. The non-destructive measurement on selected morphological and/or weight traits should be useful for continuously monitoring of leaf growth, predicting yield at any time during plant growth, and determining the time to harvest. [ABSTRACT FROM AUTHOR]

Leaves comprise one of the most important organs for plant growth and development. Although there have been some reports on leaf development and the establishment of leaf polarity, their regulatory mechanisms are not very clear. In this study, we isolated a NAC (NAM, ATAF, and CUC) transcription factor (TF), i.e., IbNAC43, from Ipomoea trifida, which is a wild ancestor of sweet potato. This TF was highly expressed in the leaves and encoded a nuclear localization protein. The overexpression of IbNAC43 caused leaf curling and inhibited the growth and development of transgenic sweet potato plants. The chlorophyll content and photosynthetic rate in transgenic sweet potato plants were significantly lower than those in wild-type (WT) plants. Scanning electron microscopy (SEM) and paraffin sections showed that the ratio of cells in the upper and lower epidermis of the transgenic plant leaves was unbalanced; moreover, the abaxial epidermal cells were irregular and uneven in transgenic plants. In addition, the xylem of transgenic plants was more developed than that of WT plants, while their lignin and cellulose contents were significantly higher than those of WT. Quantitative real-time PCR (qRT-PCR) analysis showed that the overexpression of IbNAC43 upregulated the genes involved in leaf polarity development and lignin biosynthesis in transgenic plants. Moreover, it was found that IbNAC43 could directly activate the expression of the leaf adaxial polarity-related genes IbREV and IbAS1 by binding to their promoters. These results indicate that IbNAC43 might play a critical role in plant growth by affecting the establishment of leaf adaxial polarity. This study provides new insights regarding leaf development. [ABSTRACT FROM AUTHOR]

Polyploidization results in significant changes in the morphology and physiology of plants, with increased growth rate and genetic gains as the number of chromosomes increases. In this study, the leaf functional traits, photosynthetic characteristics, leaf cell structure and transcriptome of Camellia sinensis were analyzed. The results showed that triploid tea had a significant growth advantage over diploid tea, the leaf area was 59.81% larger, and the photosynthetic capacity was greater. The morphological structure of triploid leaves was significantly different, the xylem of the veins was more developed, the cell gap between the palisade tissue and the sponge tissue was larger and the stomata of the triploid leaves were also larger. Transcriptome sequencing analysis revealed that in triploid tea, the changes in leaf morphology and physiological characteristics were affected by the expression of certain key regulatory genes. We identified a large number of genes that may play important roles in leaf development, especially genes involved in photosynthesis, cell division, hormone synthesis and stomata development. This research will enhance our understanding of the molecular mechanism underlying tea and stomata development and provide a basis for molecular breeding of high-quality and high-yield tea varieties. [ABSTRACT FROM AUTHOR]

SUMMARY: Natural antisense long non‐coding RNAs (lncNATs) are involved in the regulation of gene expression in plants, modulating different relevant developmental processes and responses to various stimuli. We have identified and characterized two lncNATs (NAT1UGT73C6 and NAT2UGT73C6, collectively NATsUGT73C6) from Arabidopsis thaliana that are transcribed from a gene fully overlapping UGT73C6, a member of the UGT73C subfamily of genes encoding UDP‐glycosyltransferases (UGTs). Expression of both NATsUGT73C6 is developmentally controlled and occurs independently of the transcription of UGT73C6 in cis. Downregulation of NATsUGT73C6 levels through artificial microRNAs results in a reduction of the rosette area, while constitutive overexpression of NAT1UGT73C6 or NAT2UGT73C6 leads to the opposite phenotype, an increase in rosette size. This activity of NATsUGT73C6 relies on its RNA sequence and, although modulation of UGT73C6 in cis cannot be excluded, the observed phenotypes are not a consequence of the regulation of UGT73C6 in trans. The NATsUGT73C6 levels were shown to affect cell proliferation and thus individual leaf size. Consistent with this concept, our data suggest that the NATsUGT73C6 influence the expression levels of key transcription factors involved in regulating leaf growth by modulating cell proliferation. These findings thus reveal an additional regulatory layer on the process of leaf growth. In this work, we characterized at the molecular level two long non‐coding RNAs (NATsUGT73C6) that are transcribed in the opposite direction to UGT73C6, a gene encoding a glucosyltransferase involved in brassinosteroid homeostasis in A. thaliana. Our results indicate that NATsUGT73C6 expression influences leaf growth by acting in trans and by modulating the levels of transcription factors that are involved in the regulation of cell proliferation. Significance Statement: In this work we characterized at the molecular level two long non‐coding RNAs (NATsUGT73C6) that are transcribed in the opposite direction to UGT73C6, a gene encoding a glucosyltransferase involved in brassinosteroid homeostasis in Arabidopsis thaliana. Our results indicate that NATsUGT73C6 expression influences leaf growth by acting in trans and by modulating the levels of transcription factors that are involved in the regulation of cell proliferation. [ABSTRACT FROM AUTHOR]

Callose, mainly deposited at the cell plate and in the newly formed cell wall at a very low level, is critical for cell activity and growth in plants. The genetic control and function of callose synthases, responsible for the synthesis of callose, are largely unknown in maize. In this study, we cloned a maize callose synthase, SLM1 (Seedling Lethal Mutant1) encoding for a GLUCAN SYNTHASE-LIKE (GSL) gene, from a seedling lethal mutant. Three different point mutations confirmed the key role of SLM1 to maintain maize normal growth. SLM1 was specifically expressed in immature leaf vascular with an enrichment in phloem of developing vasculature. Consistently, slm1 had severe defects in vasculature and leaf development, and terminated growth about 2 weeks after germination. Thus, SLM1 is a key gene to maintain normal growth by controlling leaf vascular development and cell activities. Loss of SLM1 function interrupted severely the important signaling pathways in which cell cyclin and histone related genes are involved. Our study reveals the critical function of a maize GSL gene and also its downstream signaling to maintain a normal growth of maize. [ABSTRACT FROM AUTHOR]

In Metrodorea nigra, a Rutaceae species with rhythmic growth, the shoot apex in the dormant stage is enclosed by modified stipules. The young organs are fully covered with peltate secretory trichomes, and these structures remain immersed in a hyaline exudate within a hood‐shaped structure. Our study focused on the morpho‐functional characterization of the peltate trichomes and cytological events associated with secretion.Shoot apices were collected during both dormant and active stages and processed for anatomical, cytochemical and ultrastructural studies.Trichomes initiate secretion early on, remain active throughout leaf development, but collapse as the leaves expand; at which time secretory cavities start differentiation in the mesophyll and secretion increases as the leaf reaches full expansion. The subcellular apparatus of the trichome head cells is consistent with hydrophilic and lipophilic secretion. Secretion involves two vesicle types: the smaller vesicles are PATAg‐positive (periodic acid/thiocarbohydrazide/silver proteinate) for carbohydrates and the larger ones are PATAg‐negative. In the first phase of secretory activity, the vesicles containing polysaccharides discharge their contents through exocytosis with the secretion accumulating beneath the cuticle, which detaches from the cell wall. Later, a massive discharge of lipophilic substances (lipids and terpenes/phenols) results in their accumulation between the wall and cuticle. Release of the secretions occurs throughout the cuticular microchannels.Continued protection of the leaves throughout shoot development is ensured by replacement of the collapsed secretory trichomes by oil‐secreting cavities. Our findings provide new perspectives for understanding secretion regulation in shoot apices of woody species with rhythmic growth. [ABSTRACT FROM AUTHOR]

Life evolved in the presence of reactive oxygen species (ROS) which resulted in an early integration of ROS signals and properties for cellular physiology. Originally ROS were viewed merely as metabolic by-products, but now they are viewed as conserved regulators of physiological and developmental processes throughout all kingdoms of life. Plants monitor constantly the fluctuating environmental conditions in which they grow, for which ROS signaling is essential. However, in recent years it has become clear that plants also use ROS homeostasis to guide their development. Here, an overview is presented for the role of ROS gradients and homeostasis in the development of leaves from the shoot apical meristem based mainly on the model plant species Arabidopsis thaliana. Furthermore, this chapter summarizes current knowledge on the involvement of different ROS species and molecular components in the regulation of leaf development. Although our current understanding of how plants employ ROS to guide their development is far from complete, it is clear that ROS is utilized during many developmental phases of leaf growth. [ABSTRACT FROM AUTHOR]

Leaves and flowers are crucial for the growth and development of higher plants. In this study we identified a mutant with narrow leaflets and early flowering (nlef) in an ethyl methanesulfonate-mutagenized population of woodland strawberry (Fragaria vesca) and aimed to identify the candidate gene. Genetic analysis revealed that a single recessive gene, nlef, controlled the mutant phenotype. We found that FvH4_1g25470, which encodes a putative DNA polymerase α with a polymerase and histidinol phosphatase domain (PHP), might be the candidate gene, using bulked segregant analysis with whole-genome sequencing, molecular markers, and cloning analyses. A splice donor site mutation (C to T) at the 5′ end of the second intron led to an erroneous splice event that reduced the expression level of the full-length transcript of FvePHP in mutant plants. FvePHP was localized in the nucleus and was highly expressed in leaves. Silencing of FvePHP using the virus-induced gene silencing method resulted in partial developmental defects in strawberry leaves. Overexpression of the FvePHP gene can largely restore the mutant phenotype. The expression levels of FveSEP1, FveSEP3, FveAP1, FveFUL, and FveFT were higher in the mutants than those in 'Yellow Wonder' plants, probably contributing to the early flowering phenotype in mutant plants. Our results indicate that mutation in FvePHP is associated with multiple developmental pathways. These results aid in understanding the role of DNA polymerase in strawberry development. [ABSTRACT FROM AUTHOR]

Mulberry leaf shape is an important agronomic trait indicating yield, growth, development, and habitat variation. China was the earliest country in the world to grow mulberry for sericulture, and it is also one of the great contributions of the Chinese nation to human civilization. ATAC‐seq (Assay for Transposase Accessible Chromatin using sequencing) is a recently developed technique for genome‐wide analysis of chromatin accessibility. The samples used for ATAC sequencing in this study were divided into two groups of whole leaves (CK‐1 and CK‐2) and lobed leaves (HL‐1 and HL‐2), with two replicates in each group. The related motif analysis, differential expression motif screening, and functional annotation of mulberry leaf shape differences were performed by raw letter analysis to finally obtain the transcription factors (TFs) that lead to the production of heteromorphic leaves. These transcription factors are common in plants, especially the TCP family, shown to be associated with leaf development and growth in other woody plants and are a potential transcription factor responsible for leaf shape differences in mulberry. Dissecting the regulatory mechanisms of leaf shape of different forms of mulberry leaves by ATAC‐seq is an important way to protect mulberry germplasm resources and improve mulberry yield. It is conducive to cultivating mulberry varieties with high resistance to adversity, promoting the sustainable development of sericulture, and protecting and improving the ecological environment. [ABSTRACT FROM AUTHOR]

SUMMARY: Ammonium (NH4+)‐based fertilization efficiently mitigates the adverse effects of nitrogen fertilization on the environment. However, high concentrations of soil NH4+ provoke growth inhibition, partly caused by the reduction of cell enlargement and associated with modifications of cell composition, such as an increase of sugars and a decrease in organic acids. Cell expansion depends largely on the osmotic‐driven enlargement of the vacuole. However, the involvement of subcellular compartmentation in the adaptation of plants to ammonium nutrition has received little attention, until now. To investigate this, tomato (Solanum lycopersicum) plants were cultivated under nitrate and ammonium nutrition and the fourth leaf was harvested at seven developmental stages. The vacuolar expansion was monitored and metabolites and inorganic ion contents, together with intracellular pH, were determined. A data‐constrained model was constructed to estimate subcellular concentrations of major metabolites and ions. It was first validated at the three latter developmental stages by comparison with subcellular concentrations obtained experimentally using non‐aqueous fractionation. Then, the model was used to estimate the subcellular concentrations at the seven developmental stages and the net vacuolar uptake of solutes along the developmental series. Our results showed ammonium nutrition provokes an acidification of the vacuole and a reduction in the flux of solutes into the vacuoles. Overall, analysis of the subcellular compartmentation reveals a mechanism behind leaf growth inhibition under ammonium stress linked to the higher energy cost of vacuole expansion, as a result of alterations in pH, the inhibition of glycolysis routes and the depletion of organic acids. Significance Statement: Ammonium nutrition provoked tomato growth inhibition, partly caused by the reduction of cell enlargement. Combining in vivo pH measurement, non‐aqueous fractionation and mathematical modeling, we report that the decrease in vacuolar pH and organic acid concentrations incurred an increase in the energy cost of solute accumulation in the vacuole, and thus limited cell growth under ammonium nutrition. [ABSTRACT FROM AUTHOR]

Cyclins are involved in cell division and proliferation by activating enzymes required for the cell cycle progression. Our genome-wide analysis identified 76 cyclin genes in Brassica rapa, which were divided into nine different types (A-, B-, C-, D-, H-, L-, P-, T-, and SDS-type). Cyclin genes were unevenly scattered on all chromosomes, with a maximum of 10 on A08 and a minimum of 2 on A04. The gene structure and conserved motif analysis showed that the cyclins which belonged to the same type or subgroup have a comparable intron/exon pattern or motif. A total of 14 collinear gene pairs suggested that the B. rapa cyclin genes experienced a mass of segmental duplication. The Ka/Ks analysis revealed that the Brcyclin gene family has undergone an extensive purifying pressure. By analyzing the cis-elements in the promoters, we identified 11 cis-elements and five of them are related to the hormone response. We observed 48 potential miRNAs targeting 44 Brcyclin genes, which highlighted the involvement of miRNAs in the regulation of cyclin genes. An association analysis between the leaf size and SNPs in mutants and a transcriptome analysis of two Chinese cabbage-cabbage translocation lines also showed that the Brcyclin gene family was involved in the development of the leaves. The functional characterization of the B. rapa cyclin gene family will provide the foundation for future physiological and genetic studies in the regulation of leaf growth. [ABSTRACT FROM AUTHOR]

AINTEGUMENTA-LIKE (AIL) transcription factors are widely studied and play crucial roles in plant growth and development. However, the functions of the AIL family in legume species are largely unknown. In this study, 11 MtAIL genes were identified in the model legume Medicago truncatula, of which four of them are MtANTs. In situ analysis showed that MtANT1 was highly expressed in the shoot apical meristem (SAM) and leaf primordium. Characterization of mtant1 mtant2 mtant3 mtant4 quadruple mutants and MtANT1-overexpressing plants revealed that MtANTs were not only necessary but also sufficient for the regulation of leaf size, and indicated that they mainly function in the regulation of cell proliferation during secondary morphogenesis of leaves in M. truncatula. This study systematically analyzed the MtAIL family at the genome-wide level and revealed the functions of MtANTs in leaf growth. Thus, these genes may provide a potential application for promoting the biomass of legume forages. [ABSTRACT FROM AUTHOR]

Leaf size is a crucial trait in eggplant breeding, as it influences photosynthesis, plant biomass and management. However, little is known about the molecular mechanism regulating leaf size in eggplant. This study reports a small leaf mutant (slf) generated with the mutagen ethyl methane sulfonate (EMS). The slf mutant showed restricted cell proliferation and an increased content of auxin. Transcriptome analysis revealed that several genes involved in auxin signaling are upregulated in slf. Exogenous application of auxinole, an auxin antagonist of TIR1/AFB receptors, repressed the expression of these genes and restored leaf growth of slf, suggesting that the small leaf size of slf is likely associated with auxin signaling. This study provides essential clues to unveil the molecular mechanism of leaf size regulation in eggplant. [ABSTRACT FROM AUTHOR]

Plant polyploidization changes its leaf morphology and leaf development patterns. Understanding changes in leaf morphology and development patterns is a prerequisite and key to studying leaf development in polyploid plants. In this study, we quantified and analyzed the differences in leaf morphology, leaf growth polarity, and leaf size between diploid and tetraploid birches (Betula pendula subsp. pendula), and preliminarily investigated genes involved in leaf growth and development in birch. The results showed significant changes in leaf morphology in tetraploid birches, especially the basal part of the leaf. In addition, the proximal growth rate of tetraploid leaves was altered. The changed proximal growth rate did not affect the growth polarity pattern of tetraploid leaves. The leaf area of tetraploid was significantly larger than that of diploid birch. The difference in leaf size was mainly due to differences in their growth rates in the middle and late stages of leaf development. Increased cell expansion capacity was the major reason for the enormous leaves of tetraploid birch; however, cell proliferation did not contribute to the larger tetraploid leaf. The gene expression of ATHB12 was associated with cell size and leaf area, and may be a critical gene affecting the leaf size in diploid and tetraploid birches. The results will provide valuable insights into plant polyploid leaf development and a theoretical basis for later investigations into the molecular mechanisms underlying the gigantism of tetraploid birch leaves. [ABSTRACT FROM AUTHOR]

• The leaf surfaces of C. apiculatum possess peltate glandular and non-glandular trichomes. • Trichome development begins early but may occur throughout leaf growth. • Both trichome densities decreased with leaf maturation. • Histochemistry revealed a number of medicinally beneficial phytocompounds. Combretum apiculatum Sond. subsp. apiculatum is an important plant used in the traditional medicinal treatment of many diseases including gastrointestinal disorders, conjunctivitis, aches and leprosy. The plant's medicinal properties are putatively associated with secondary metabolites present in trichomes found on the leaf surfaces. This study aimed to investigate the distribution and morphology of the glandular trichomes of C. apiculatum at various stages of leaf development (emergent, young and mature) using stereo-, compound-light- and scanning electron microscopy, as well as to determine the leaf phytochemical constituents and to correlate the plant's medicinal properties at the cellular level by histochemical analyses. The microscopical studies revealed multicellular subsessile/sessile peltate, glandular trichomes and unicellular to multicellular non-glandular trichomes at all leaf developmental stages. Emergent leaves consisted of dense distributions of trichomes located in epidermal depressions, suggesting emergence during the early stages of leaf development. Trichome density decreased with leaf maturation, potentially attributable to the leaf expansion theory. Histochemical analyses on the leaves and trichomes detected alkaloids, phenolic compounds, lignin, terpenoids, resin acids, pectins, mucilage, carboxylated and hydroxylated polysaccharides, polyphenols, total lipids, total proteins and nucleic acids, indicating cell viability. These compounds possess medicinal properties, thereby providing supporting evidence for the plant's traditional medical use. [ABSTRACT FROM AUTHOR]