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Excessive aluminum ions (Al3+) in acidic soil can have a toxic effect on watermelons, restricting plant growth and reducing yield and quality. In this study, we found that exogenous application of nitric oxide (NO) could increase the photochemical efficiency of watermelon leaves under aluminum stress by promoting closure of leaf stomata, reducing malondialdehyde and superoxide anion in leaves, and increasing POD and CAT activity. These findings showed that the exogenous application of NO improved the ability of watermelon to withstand aluminum stress. To further reveal the mitigation mechanism of NO on watermelons under aluminum stress, the differences following different types of treatments—normal growth, Al, and Al + NO—were shown using de novo sequencing of transcriptomes. In total, 511 differentially expressed genes (DEGs) were identified between the Al + NO and Al treatment groups. Significantly enriched biological processes included nitrogen metabolism, phenylpropane metabolism, and photosynthesis. We selected 23 genes related to antioxidant enzymes and phenylpropane metabolism for qRT-PCR validation. The results showed that after exogenous application of NO, the expression of genes encoding POD and CAT increased, consistent with the results of the physiological indicators. The expression patterns of genes involved in phenylpropanoid metabolism were consistent with the transcriptome expression abundance. These results indicate that aluminum stress was involved in the inhibition of the photosynthetic pathway, and NO could activate the antioxidant enzyme defense system and phenylpropane metabolism to protect cells and scavenge reactive oxygen species. This study improves our current understanding by comprehensively analyzing the molecular mechanisms underlying NO-induced aluminum stress alleviation in watermelons. [ABSTRACT FROM AUTHOR]

This study evaluated the salt tolerance in 40 celery germplasm resources to clarify the different salt tolerances of celery germplasm. A gradient treatment with different concentrations of NaCl solutions (100, 200, and 300 mmol·L−1) was used to simulate salt stress. After 15 days of salt treatment, 14 indicators related to plant growth, physiology, and biochemistry were determined. The results showed that different celery varieties responded differently to salt stress. Notably, there were significant variations in below-ground dry weight, root–crown ratio, antioxidant enzyme activity, and soluble protein content among the accessions under salt stress. Principal component analysis was used to identify important indices for evaluating salt tolerance, including plant height, spread, content of soluble protein, and so on. A comprehensive evaluation was conducted utilizing the salt damage index, principal component analysis, affiliation function analysis, and cluster analysis. The 40 celery germplasms were classified into five highly salt-tolerant, seven salt-tolerant, fifteen moderately salt-tolerant, nine salt-sensitive, and four highly salt-sensitive germplasms. SHHXQ, MXKQ, XBQC, XQ, and TGCXBQ were highly salt-tolerant germplasms, and BFMSGQ, HNXQ, ZQ, and MGXQW were highly salt-sensitive germplasms. The results of this study provide a reference for the variety of celery cultivation in saline areas and lay a foundation for the selection and breeding of salt-tolerant varieties of celery. [ABSTRACT FROM AUTHOR]

The genus Apium, belonging to the family Apiaceae, comprises roughly 20 species. Only two species, Apium graveolens and Apium leptophyllum, are available in China and are both rich in nutrients and have favorable medicinal properties. However, the lack of genomic data has severely constrained the study of genetics and evolution in Apium plants. In this study, Illumina NovaSeq 6000 and Nanopore sequencing platforms were employed to identify the mitochondrial genomes of A. graveolens and A. leptophyllum. The complete lengths of the mitochondrial genomes of A. graveolens and A. leptophyllum were 263,017 bp and 260,164 bp, respectively, and contained 39 and 36 protein-coding genes, five and six rRNA genes, and 19 and 20 tRNA genes. Consistent with most angiosperms, both A. graveolens and A. leptophyllum showed a preference for codons encoding leucine (Leu). In the mitochondrial genome of A. graveolens, 335 SSRs were detected, which is higher than the 196 SSRs found in the mitochondrial genome of A. leptophyllum. Studies have shown that the most common RNA editing type is C-to-U, but, in our study, both A. graveolens and A. leptophyllum exhibited the U-C editing type. Furthermore, the transfer of the mitochondrial genomes of A. graveolens and A. leptophyllum into the chloroplast genomes revealed homologous sequences, accounting for 8.14% and 4.89% of the mitochondrial genome, respectively. Lastly, in comparing the mitochondrial genomes of 29 species, it was found that A. graveolens, A. leptophyllum, and Daucus carota form a sister group with a support rate of 100%. Overall, this investigation furnishes extensive insights into the mitochondrial genomes of A. graveolens and A. leptophyllum, thereby enhancing comprehension of the traits and evolutionary patterns within the Apium genus. Additionally, it offers supplementary data for evolutionary and comparative genomic analyses of other species within the Apiaceae family. [ABSTRACT FROM AUTHOR]

The plant mitochondria play a crucial role in various cellular energy synthesis and conversion processes and are essential for plant growth. Watercress (Oenanthe javanica) is a fast-growing vegetable with strong adaptability and wide cultivation range, and it possesses high nutritional value. In our study, we assembled the O. javanica mitochondrial genome using the Illumina and Nanopore sequencing platforms. The results revealed that the mitochondrial genome map of watercress has a circular structure of 384,074 bp, containing 28 tRNA genes, 3 rRNA genes, and 34 protein-coding genes. A total of 87 SSR (simple sequence repeat) loci were detected, with 99% composed of palindrome repeats and forward repeats, while no complementary repeats were identified. Codon preference analysis indicated that watercress prefers to use codons encoding leucine, isoleucine, and serine with a preference for A/U-ending codons. Phylogenetic analysis showed that watercress is closely related to species of Bupleurum, Apium, Angelica, and Daucus, with the closest evolutionary relationship observed with Saposhnikovia divaricata and Apium graveolens. This study provides a valuable resource for the study of the evolution and molecular breeding of watercress. [ABSTRACT FROM AUTHOR]

Asparagus belongs to the Liliaceae family and has important economic and pharmacological value. Lignin plays a crucial role in cell wall structural integrity, stem strength, water transport, mechanical support and plant resistance to pathogens. In this study, various biological methods were used to study the mechanism of shading on the asparagus lignin accumulation pathway. The physiological results showed that shading significantly reduced stem diameter and cell wall lignin content. Microstructure observation showed that shading reduced the number of vascular bundles and xylem area, resulting in decreased lignin content, and thus reducing the lignification of asparagus. Cinnamic acid, caffeic acid, ferulic acid and sinapyl alcohol are crucial intermediate metabolites in the process of lignin synthesis. Metabolomic profiling showed that shading significantly reduced the contents of cinnamic acid, caffeic acid, ferulic acid and sinapyl alcohol. Transcriptome profiling identified 37 differentially expressed genes related to lignin, including PAL, C4H, 4CL, CAD, CCR, POD, CCoAOMT, and F5H related enzyme activity regulation genes. The expression levels of POD, CCoAOMT, and CCR genes were significantly decreased under shading treatment, while the expression levels of CAD and F5H genes exhibited no significant difference with increased shading. The downregulation of POD, CCoAOMT genes and the decrease in CCR gene expression levels inhibited the activities of the corresponding enzymes under shading treatment, resulting in decreased downstream content of caffeic acid, ferulic acid, sinaperol, chlorogenic acid and coniferin. A significant decrease in upstream cinnamic acid content was observed with shading, which also led to decreased downstream metabolites and reduced asparagus lignin content. In this study, transcriptomic and metabolomic analysis revealed the key regulatory genes and metabolites of asparagus lignin under shading treatment. This study provides a reference for further understanding the mechanism of lignin biosynthesis and the interaction of related genes. [ABSTRACT FROM AUTHOR]

This study sequenced and assembled the chloroplast (cp) genome of Brasenia schreberi cv. 'Mahu Chuncai', a novel variety of B. schreberi rich in nutrients with distinctive characteristics, unlike other varieties in China. The cpDNA genome of 'Mahu Chuncai' has a typical quadripartite structure, with a full length of 158,973 bp, including 88 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The phylogenetic analysis revealed that all species can be divided into three main clades. Results from inverted repeats (IR) boundary analysis revealed substantial differences between Brasenia and Cabomba species. The cpDNA genome of B. schreberi identified was strongly related to Brasenia species but appeared to be a distant relative of Cabomba aquatica more than other species in Cabombaceae. In contrast with the species from Cabombaceae, 'Mahu Chuncai' was a close relative of B. schreberi MN315507.1, which was a distant relative of C. aquatica MG720559.1. Furthermore, we found four potential molecular markers, i.e., ycf1 in the IR region, psbT in the LSC region, and ndhF and rps15 in the SSC region. Collectively, our findings confirm the phylogenetic evolution and cultivation origin of B. schreberi. We identified genetic characteristics and nucleotide diversity hotspots, which provides a theoretical basis for additional research on variety identification, germplasm resources, and molecular breeding of the precious vegetable. [ABSTRACT FROM AUTHOR]

Nasturtium officinale is a cadmium (Cd) accumulator plant, but its phytoremediation capacity is low compared to other hyperaccumulators. To improve the phytoremediation capacity, the seedlings of N. officinale was grown in Cd-contaminated paddy soils, and the effects of diethyl aminoethyl hexanoate (DA-6) on N. officinale growth and Cd accumulation were studied. DA-6 increased the shoot biomass of N. officinale, and had a quadratic polynomial regression relationship with root and shoot biomass. DA-6 had no significant effects on chlorophyll a, chlorophyll b, and carotenoid contents, increased peroxidase, superoxide dismutase, and catalase activities, and decreased the soluble protein content. DA-6 also increased the Cd content and Cd extraction of N. officinale to some extent, and had a quadratic polynomial regression relationship with the root Cd content, shoot Cd content, root Cd extraction, and shoot Cd extraction. Significant correlations were found among plant biomass, chlorophyll content, Cd content, Cd extraction, and antioxidant enzyme activity. Furthermore, soluble protein content and soil exchangeable Cd was significantly correlated with plant Cd content and Cd extraction. Therefore, DA-6 can promote N. officinale growth and improve its phytoremediation capacity for Cd-contaminated paddy soils, with a recommend optimum dose of 20 mg/L. [ABSTRACT FROM AUTHOR]

To assess the effects of brassinolide (BR) on the growth and phytoremediation ability of cadmium (Cd) accumulator plants, different BR concentrations were applied to emerged accumulator plant Nasturtium officinale growing in Cd-contaminated soil. Brassinolide application increased the biomass, photosynthetic pigment content, and antioxidant enzyme activity of N. officinale. When N. officinale was treated with 1.5 mg L−1 of BR, the highest shoot biomass was obtained, recording an increase of 26.06%, compared to the control. In addition, BR treatment decreased the Cd contents in the shoots of N. officinale, and the BR concentrations of 0.5, 1.0, 1.5, and 2.0 mg L−1 decreased the Cd content in shoots by 10.49%, 12.11%, 20.13%, and 17.23%, respectively, compared to the control. Brassinolide treatment also slightly inhibited the transportation of Cd from the roots to shoots. The findings revealed that BR had no significant effects on the Cd extraction amounts by stems, leaves, and shoots of N. officinale. However, BR promoted the growth of N. officinale and inhibited the Cd uptakes in the above-ground part of N. officinale. Thus, N. officinale could be used as a wild vegetable in the Cd-contaminated soil, although not suitable for phytoextraction as an accumulator plant. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three BoaAOP2s were isolated and edited using CRISPR/Cas9 system in Chinese kale. • The boaaop2 mutants of T1 generations were obtained in Chinese kale. • The content of glucoraphanin was increased and gluconapin was decreased in mutants. • Expression of upstream genes of glucosinolate biosynthesis were decreased in mutants. • BoaAOP2.1 is an effective gene for the alkenylation of aliphatic glucosinolates. Glucoraphanin (GRA) is an aliphatic glucosinolate (GSL), and its hydrolysis product has powerful anticancer activity. ALKENYL HYDROXALKYL PRODUCING 2 (AOP2) gene, encodes a 2-oxoglutarate-dependent dioxygenase, which can catalyze GRA to form gluconapin (GNA). However, GRA only present in trace amounts in Chinese kale. To increase the content of GRA in Chinese kale, three copies of BoaAOP2 were isolated and edited using CRISPR/Cas9 system. The content of GRA was 11.71- to 41.29-fold (0.082–0.289 μmol g−1 FW) higher in T1 generation of boaaop2 mutants than in wild-type plants, and this was accompanied by an increase in the GRA/GNA ratio and reductions in the content of GNA and total aliphatic GSLs. BoaAOP2.1 is an effective gene for the alkenylation of aliphatic GSLs in Chinese kale. Overall, targeted editing of CRISPR/Cas9-mediated BoaAOP2s altered aliphatic GSL side-chain metabolic flux and enhanced the GRA content in Chinese kale, suggesting that metabolic engineering of BoaAOP2s has huge potential in improving nutritional quality of Chinese kale. [ABSTRACT FROM AUTHOR]

• The appearance and nutritional quality of leaf mustard cultivars varied greatly. • Most phytochemicals content and antioxidant capacity decreased by fermentation. • The odor of Guizhou suancai was correlated with gluconapin. • The taste of Guizhou suancai was correlated with sinigrin. The flavor of Guizhou suancai fermented by the emerging varieties Zhuchang–2 (ZC–2) and Zhuchang Red (ZC Red) is superior to that of ZC–1, a typical local variety of leaf mustard in Guizhou Province, China. Here, changes in phytochemical qualities during the fermentation of three Guizhou suancai were characterized to identify the causes underlying differences in flavor. The content of pigments, antioxidants, gluconapin, gluconasturtiin, and total isothiocyanates, and antioxidant capacity were highest in fresh ZC Red. The content of sinigrin, indolic glucosinolates, and total glucosinolate breakdown products was highest in fresh ZC–2. The content of phytochemicals, with the exception of carotenoids, was significantly decreased after fermentation. Odor was correlated with gluconapin, while taste was correlated with sinigrin. These findings provide detailed insights into the sensory and phytochemical properties of three Guizhou suancai that could facilitate the selection of raw material varieties. [ABSTRACT FROM AUTHOR]

• Mustard sprouts are rich in health-promoting compounds and antioxidant activities. • Root mustard contained optimum levels of antioxidants and antioxidant activities. • Stem mustard and half of root mustard have higher glucosinolates content. • The level of glucosinolates determine different flavors and application of mustard. • S1, L4, and R11 can be used as functional cultivars or future hybrid breeding. Mustard has nutritional benefits to human health and come in diverse flavors, while the edible sprouts have a short cycle, high nutrition, and hygienic characteristics. This study was designed to investigate the differences in chlorophyll, carotenoids, ascorbic acid, phenolic compounds, antioxidant activities, and glucosinolates in the sprouts of three mustard types (root, stem, and leaf mustards) from a core collection of 41 cultivars. The content of chlorophyll and carotenoids was only slightly different among the three types. Root mustard cultivars had considerable phenolic compound content (17.31 mg g −1) and antioxidant activities. In addition, twelve glucosinolates were identified in the mustard sprout cultivars, and the stem mustard and nearly half of the root mustard had the highest averages (140.38 μmol g −1 and 159.98 μmol g −1, respectively), while the lowest average was detected in leaf mustard (78.00 μmol g −1). Root mustard sprouts are suitable for pickling and processing, stem mustard sprouts contribute to mustard-flavored condiments, and leaf mustard sprouts are widely used for fresh eating or making mild mustard condiments based on the glucosinolates content. S1, L4, and R11 would be useful as functional cultivars or elite crossbreeding germplasms due to their excellent carotenoids, antioxidant activity, and glucosinolates traits, respectively. In conclusion, mustard sprouts were assigned nutritional characteristics and can be diversely popularized and utilized for their edible value. [ABSTRACT FROM AUTHOR]

Wasabi (Eutrema japonicum) is a vegetable of Brassicaceae family, currently cultivated in East Asia. It is rich in nutritional and has a spicy flavour. It is regarded as a rare condiment worldwide. Its genetic profile for yield improvement and the development of E. japonicum germplasm resources remains unknown. Cognizant of this, this study sequenced and assembled the chloroplast (cp) genome of E. japonicum to enrich our genomic information of wasabi and further understand genetic relationships within the Eutrema species. The structural characteristics, phylogeny, and evolutionary relationship of cp genomes among other Brassicaceae plants were analyzed and compared to those of Eutrema species. The cp genome of E. japonicum has 153,851 bp with a typical quadripartite structure, including 37 tRNA genes, 8 rRNA genes, and 87 protein-coding genes. It contains 290 simple sequence repeats and prefers to end their codons with an A or T, which is the same as other Brassicaceae species. Moreover, the cp genomes of the Eutrema species had a high degree of collinearity and conservation during the evolution process. Nucleotide diversity analysis revealed that genes in the IR regions had higher Pi values than those in LSC (Large single copy) and SSC (Small single copy) regions, making them potential molecular markers for wasabi diversity studies. The analysis of genetic distance between Eutrema plants and other Brassicacea plants showed that intraspecies variation was found to be low, while large differences were found between genera and species. Phylogenetic analysis based on 29 cp genomes revealed the existence of a close relationship amongst the Eutrema species. Overall, this study provides baseline information for cp genome-based molecular breeding and genetic transformation studies of Eutrema plants. [ABSTRACT FROM AUTHOR]