Melatonin, a pleiotropic small molecule, is employed in horticultural crops to delay senescence and preserve postharvest quality. In this study, 100 µM melatonin treatment delayed a decline in the color difference index h* and a*, maintaining the content of chlorophyll and carotenoids, thereby delaying the yellowing and senescence of Chinese kale. Transcriptome analysis unequivocally validates melatonin’s efficacy in delaying leaf senescence in postharvest Chinese kale stored at 20 °C. Following a three-day storage period, the melatonin treatment group exhibited 1637 differentially expressed genes (DEGs) compared to the control group. DEG analysis elucidated that melatonin-induced antisenescence primarily governs phenylpropanoid biosynthesis, lipid metabolism, plant signal transduction, and calcium signal transduction. Melatonin treatment up-regulated core enzyme genes associated with general phenylpropanoid biosynthesis, flavonoid biosynthesis, and the α-linolenic acid biosynthesis pathway. It influenced the redirection of lignin metabolic flux, suppressed jasmonic acid and abscisic acid signal transduction, and concurrently stimulated auxin signal transduction. Additionally, melatonin treatment down-regulated RBOH expression and up-regulated genes encoding CaM, thereby influencing calcium signal transduction. This study underscores melatonin as a promising approach for delaying leaf senescence and provides insights into the mechanism of melatonin-mediated antisenescence in postharvest Chinese kale.

Chinese kale sprouts have garnered attention owing to its rich health -promoting compounds. This study aimed to investigate the effects of different light qualities (white, blue, and red light) and melatonin (100 mu mol L -1 ), both individually and in combination, on the growth and accumulation of health -promoting compounds in Chinese kale sprouts. Red light positively influenced sprout growth (compared with white light, plant height and fresh weight increased by 16.67 % and 4.87 %, respectively), and the red light + melatonin treatment further enhanced growth (compared with single red light, the plant height and fresh weight increased by 14.97 % and 12.29 %, respectively), while increasing glucosinolate accumulation through the up -regulation of glucosinolate biosynthetic genes ( UGT74B1 , CYP83B1 , SOT18 and IGMT1 ). Conversely, blue light inhibited sprout growth, elevated the expression levels of PAL , CHS , CHI , GGP , and PAX , improved antioxidant levels, and accelerated the accumulation of aliphatic glucosinolates, reducing indolic glucosinolates. The blue light + melatonin treatment promoted the accumulation of sprout biomass and anthocyanins (11.91 % and 13.33 % higher than that of single blue light). The study unveiled various pathways influencing plant growth, development, and secondary metabolite accumulation, including plant circadian rhythms, ascorbate and aldarate metabolism, phenylpropanoid biosynthesis, and glucosinolate biosynthesis.

Basella alba is a frequently consumed leafy vegetable. However, research on its nutritional components is limited. This study aimed to explore the variation in the nutritional components and antioxidant capacity of different cultivars and organs of Basella alba. Here, we primarily chose classical spectrophotometry and high-performance liquid chromatography (HPLC) to characterize the variation in nutritional components and antioxidant capacity among different organs (inflorescences, green fruits, black fruits, leaves, and stems) of eight typical cultivars of Basella alba. The determination indices (and methods) included the total soluble sugar (anthrone colorimetry), total soluble protein (the Bradford method), total chlorophyll (the ethanol-extracting method), total carotenoids (the ethanol-extracting method), total ascorbic acid (the HPLC method), total proanthocyanidins (the p-dimethylaminocinnamaldehyde method), total flavonoids (AlCl3 colorimetry), total phenolics (the Folin method), and antioxidant capacity (the FRAP and ABTS methods). The results indicated that M5 and M6 exhibited advantages in their nutrient contents and antioxidant capacities. Additionally, the inflorescences demonstrated the highest total ascorbic acid and total phenolic contents, while the green and black fruits exhibited relatively high levels of total proanthocyanidins and antioxidant capacity. In a comparison between the green and black fruits, the green fruits showed higher levels of total chlorophyll (0.77-1.85 mg g(-1) DW), total proanthocyanidins (0.62-2.34 mg g(-1) DW), total phenolics (15.28-27.35 mg g(-1) DW), and ABTS (43.39-59.16%), while the black fruits exhibited higher levels of total soluble protein (65.45-89.48 mg g(-1) DW) and total soluble sugar (56.40-207.62 mg g(-1) DW) in most cultivars. Chlorophyll, carotenoids, and flavonoids were predominantly found in the leaves of most cultivars, whereas the total soluble sugar contents were highest in the stems of most cultivars. Overall, our findings underscore the significant influence of the cultivars on the nutritional composition of Basella alba. Moreover, we observed notable variations in the nutrient contents among the different organs of the eight cultivars, and proanthocyanidins may contribute significantly to the antioxidant activity of the fruits. On the whole, this study provides a theoretical basis for the genetic breeding of Basella alba and dietary nutrition and serves as a reference for the comprehensive utilization of this vegetable.

Purple leaf mustard has garnered attention owing to its abundant anthocyanin content. This study investigated the phenolic metabolome and transcriptome of purple variety ZC-Red and green variety ZC-2. Each of the two varieties had three biological replicates, and each replicate consisted of ten leaves from five plants. Phenolic metabolome was analyzed using an ultra-high performance liquid chromatography system and tandem mass spectrometry, and the transcriptome sequencing platform was the Illumina NovaSeq 6000 platform. The green variety ZC-2 was used as the control for differential analysis. All differential metabolites and genes were significant. Findings revealed the accumulation of anthocyanins in ZC-Red, whereas ZC-2 exhibited higher levels of phenolic acids and flavonoids, excluding anthocyanins. This could be attributed to the directional preference of the phenylpropanoid metabolic flow. Transcriptome analysis highlighted the pivotal roles of phenylpropanoid metabolism and photosynthesis in color formation. In ZC-Red, nearly all anthocyanin biosynthesis genes exhibited up-regulation, with multiple genes in late biosynthesis showing increases thousands of times greater than ZC-2. Conversely, the expression of genes associated with photosystem subunits and light-harvesting complexes was down-regulated. Key candidate transcription factors, including MYB113, TT8, WRKY44, and MYB30, were identified as regulators of anthocyanin and photosynthesis. Findings contribute valuable insights into the molecular mechanisms underlying anthocyanin accumulation. Core differential metabolites such as anthocyanins and phenolic acids are of great significance to the utilization of diversified functional compounds and targeted breeding of leaf mustard.

Starch nanoparticles (sNPs) are attractive for numerous applications due to their non-toxicity, environmentally friendly nature, readily available raw materials worldwide, and biodegradability. However, the heterogeneous nature of starch makes it a challenge to prepare homogeneous sNP. The lack of existing preparation methods for small-sized sNPs (ss-sNPs) with high quality has been limiting their practical applications. In this study, we have developed a new method by combining nanoprecipitation and successive centrifugation to generate ss-sNPs with well-defined properties from six different starch types. The method is simple, environmentally friendly, requires a relatively short processing time ( <4 h) and generated sizes smaller than 50 nm diameter. The products were thoroughly investigated, structurally, microscopically, and physically. The ss-sNPs products derived from all starch types demonstrated high stability in water (up to three weeks), meeting the requirements for practically any application. The formation of near monodisperse 10 nm diameter ss-sNPs was achieved using a high amylose (more linear) starch type as starting material. However, all ss-sNPs were mainly comprised of short-chained amylopectin. This general and efficient method for producing ss-sNPs offers significant opportunities for their application in various fields.

Tobacco (Nicotiana tabacum) is a globally cultivated crop, with its quality closely associated with the color and chemical composition of cured tobacco leaves. In this experiment, the effects of spraying exogenous 2, 4-epibrassinolide (EBR) and melatonin (MT) on the development of tobacco leaves at maturity stage and the quality after curing were investigated. Both EBR and MT treatments significantly enhanced the appearance quality of tobacco leaves at the stem-drying stage. Following preharvest applications, the sugar-to-alkali ratio and potassium content increased, while the contents of starch, total alkaloids, and proteins decreased. The levels of conventional chemical components were improved, enhancing the overall coordination of the tobacco. Transcriptome analysis revealed that EBR treatment down-regulated the chlorophyll biosynthetic genes hemA, MgPEC, and ChlD, while up-regulating the chlorophyll degradation genes CHL2, SGR, and PAOs. Similarly, MT treatment down-regulated the chlorophyll biosynthetic genes FC2 and MgPEC and up-regulated the degradation genes CHL2 and SGR, thus promoting chlorophyll degradation. Furthermore, in the downstream carotenoid biosynthetic pathway, both EBR and MT treatments regulated abscisic acid-related genes, with NCEDs being up-regulated and CYP707A1s down-regulated, thereby promoting the leaf ripening. Metabolomics analysis indicated that EBR treatment primarily regulated alkaloids, terpenoids, and flavonoids, while MT treatment mainly affected flavonoids. Both treatments also reduced the accumulation of the harmful substance aristolochic acid B. Comprehensive evaluations of appearance quality, physiological parameters, transcriptome, and metabolomics analyses demonstrated that exogenous spraying of EBR and MT treatments improved the maturity and quality of cured tobacco leaves, with EBR treatment exhibiting a greater effect than MT treatment.

Baby mustard is a characteristic vegetable of the Southwest China, and its quality, including appearance quality and nutritional quality, deteriorated during the postharvest senescence process. This study investigated the effects of individual and combined treatments with 2,4-epibrassinolide (EBR) and calcium chloride (CaCl2) on the visual quality and health-promoting compounds of baby mustard stored at room temperature. In terms of appearance, individual treatments with EBR and CaCl2 were more effective than the control and combined treatment in sensory evaluation and weight loss inhibition. All three exogenous treatments maintained the content of pigments, especially individual treatments. The total chlorophyll content was 1.6-, 1.6-, and 1.1-fold higher in EBR-, CaCl2-, and EBR + CaCl2-treated samples than in control samples at 4 days, respectively. In terms of nutritional quality, all three exogenous treatments delayed the decrease in glucosinolates and soluble protein content, with EBR treatment being the most effective in preserving the content of indolic glucosinolates. Additionally, three exogenous treatments effectively maintained antioxidant levels, thereby reducing hydrogen peroxide accumulation. Combined treatment inhibited brassinosteroid signaling, revealing a potential antagonistic relationship between EBR and CaCl2. The results suggest that the three exogenous treatments delayed senescence and preserved the postharvest quality of baby mustard. EBR treatment was the most effective in preserving pigments. This experiment provides potential technical and theoretical basis for the postharvest preservation of baby mustard.

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 glu-cosinolates were identified in the mustard sprout cultivars, and the stem mustard and nearly half of the root mustard had the highest averages (140.38 limol g -1 and 159.98 limol g -1, respectively), while the lowest average was detected in leaf mustard (78.00 limol 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.

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 dioxyge-nase, 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 & mu;mol 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.

The complete nucleotide sequences of both RNAs of oat golden stripe virus (OGSV) and a wheat-infecting furovirus isolate from France, previously thought to be soil-borne wheat mosaic virus (SBWMV), have been determined. Both viruses had a similar genomic organisation to SBWMV and Chinese wheat mosaic virus, the two other furoviruses previously sequenced but had <70% nucleotides identical to them. The French isolate has been named European wheat mosaic virus (EWMV). Phylogenetic analyses supported the recognition of these isolates as distinct viruses in the genus Furovirus. Analysis of the coat protein readthrough domain on RNA2 of all furoviruses strongly predicts two mutually compatible conserved transmembrane domains that may be significant for fungus transmission. The second of these regions is eliminated by a deletion in the isolate of OGSV studied. Leaky opal (UGA) stop codons occur on both RNAs of all four furoviruses characterised and, in common with most other leaky opal codons identified in plant viruses, they are followed by a CGG codon.

The ability of white, red, and blue irradiation to maintain sensory quality, health-promoting compounds, and antioxidant capacity, and regulate glucosinolate metabolism-related gene expression in post-harvest baby mustard was studied. Irradiation with 80 µmol m-2 s-1 extended the shelf life of post-harvest baby mustard. Irradiation delayed the increase in weight loss and the decrease in sensory parameter scores and the levels of ascorbic acid, total phenolics, glucosinolate, and antioxidant capacity during storage of baby mustard. Irradiation induced the expression of glucosinolate biosynthesis genes and inhibited glucosinolate degradation gene expression. The glucosinolate content and glucosinolate metabolism-related gene expression in post-harvest baby mustard were higher under white and red light irradiation compared with blue light irradiation. These findings indicate that irradiation (80 µmol m-2 s-1 ), especially of white and red light, is an effective technique for maintaining the sensory and nutritional qualities in post-harvest baby mustard stored at 20°C. PRACTICAL APPLICATION: This study was to evaluate the effect of white, red, and blue irradiation on the sensory quality, health-promoting compounds, antioxidant capacity, and glucosinolate metabolism-related gene expression of baby mustard during post-harvest storage, providing an effective and sustainable post-harvest method to extend shelf life and maintain the post-harvest quality of baby mustard under ambient temperature storage. Irradiation (80 µmol m-2 s-1 ), especially of white and red light, is an effective technique for maintaining the sensory and nutritional qualities in post-harvest baby mustard stored at 20°C.

Purple flowering stalks and green flowering stalks of Brassica campestris are widely cultivated in the middle and upper reaches of the Yangtze River. Here, concentrations of the main health-promoting compounds and antioxidant capacity levels were characterized in different parts (leaves, peel, flesh, and inflorescences) of purple and green flowering stalks. There were significant differences in the concentrations of health-promoting compounds between the two variants; the concentrations of pigments, especially anthocyanidins, and gluconapin, were significantly higher in purple flowering stalks than in green flowering stalks, and the progoitrin content was significantly higher in green flowering stalks than in purple flowering stalks. The leaves were judged to be the most nutritional edible part because they had the highest concentrations of pigments, ascorbic acid, proanthocyanidins, flavonoids, and total phenolics. Antioxidant capacity was also highest in the leaves, and it was positively correlated with the concentration of health-promoting compounds. Purple flowering stalks and green flowering stalks were found to be rich in health-promoting compounds, especially glucosinolates. Overall, our findings indicate that consumption of the leaves and peel would provide the most health benefits. Some suggestions are provided regarding the processing and utilization of these edible components.

Mustard is an edible vegetable in the genus Brassica with tender and clean sprouts and short growth cycles that has become a rich source of nutrients required by humans. Here, the effects of dark exposure duration and planting density on the health-promoting phytochemicals and the antioxidant capacity of mustard sprouts were evaluated. The content of soluble sugar, soluble protein, chlorophyll, and carotenoids and the antioxidant capacity of mustard were higher in the two-day dark treatment; the content of indolic glucosinolates was also more affected in the dark day experiment than in the planting density experiment. The soluble sugar, soluble protein, and aliphatic and total glucosinolate levels were higher when sprouts were grown at high densities (6–7 g per tray); however, no significant variation was observed in the content of chlorophyll and carotenoids and the antioxidant capacity. The results of this study show that the optimum cultivation regime for maximizing the concentrations of nutrients of mustard plants is a planting density of 6 g of seeds per tray and a two-day dark treatment.

Wasabi (Eutrema japonicum ), also known as Japanese horseradish, is a perennial herb widely used in Japanese cuisine for its special flavour. The health-promoting phytochemicals and antioxidant capacity of four organs (leaf, petiole, rhizome, and root) of two cultivars (Chuankui–1 and Chuankui–2) of wasabi from two producing areas, Leibo and Guangyuan in Sichuan Province, China, were investigated in this study. The results showed that leaves were rich in pigments, soluble protein, ascorbic acid, and total phenolics and had the highest antioxidant capacity. Soluble sugars were highest in the petioles and were 1.1- to 5-fold higher than those in the other three organs. Glucosinolates and glucosinolate breakdown products (GBPs) were the most abundant in rhizomes, and their maximum values were 271.61 mmol kg -1 DW and 249.78 mmol kg -1 DW, respectively. The rhizomes of Chuankui–1 in Leibo and the leaves of Chuankui–1 in Guangyuan were superior in terms of glucosinolates and GBPs. These findings provide new insights that will aid the use of wasabi cultivars; they also have implications for the environmental characteristics needed to obtain better quality wasabi products. In the future, metabolome and transcriptome can be used to analyze the potential mechanism of differences among typical varieties, origins and parts.

The effect of water and sucrose treatments on the sensory quality and content of health-promoting compounds in the lateral buds of baby mustard stored at 20 °C was investigated in this study. Although water treatment maintained the content of various nutrients, the decay of baby mustard was greater under water treatment. Sucrose treatment delayed the weight loss and the decline in sensory parameter scores, chlorophyll and sucrose content; slowed the decline in antioxidant capacity by maintaining the content of carotenoids and ascorbic acid; suppressed the increase in total phenolics; and maintained and even increased the content of several individual glucosinolates in the lateral buds of baby mustard. These findings indicate that sucrose application can maintain the sensory and nutritional qualities of the lateral buds of postharvest baby mustard.

The glucosinolates and glucosinolate breakdown products (GBPs) in the seeds of three types of mustard (root, stem, and leaf mustards) from a core collection of 50 cultivars were studied. Nine glucosinolates and ten GBPs were identified, with sinigrin and 2-propenyl isothiocyanate (SIN-ITC) being the dominant glucosinolate and GBP, respectively. Among the tested cultivars, the contents of total glucosinolates and GBPs ranged from 46.84 to 89.30 mu mol g(-1) FW and from 23.07 to 82.20 mu mol g(-1) FW, respectively. Leaf mustard had both the highest average levels of glucosinolates and GBPs (65.04 mu mol g(-1) FW and 55.97 mu mol g(-1) FW, respectively) and the greatest variation in total GBP content compared with root and stem mustards. L8 had the highest content of SIN-ITC (72.06 mu mol g(-1) FW). These findings indicate that mustard seeds, especially cultivar L8, can be good candidates for functional foods since they contain extremely high levels of SIN-ITC, a potent anti-carcinogenic isothiocyanate.

The effect of melatonin treatment on the visual quality and content of health-promoting compounds in baby mustard (Brassica juncea var. gemmifera) at 20°C was investigated in this study. Application of 100 μmol L–1 melatonin was the most effective in prolonging the shelf life of baby mustard among all of the concentrations tested (1, 50, 100, and 200 μmol L–1). The 100 μmol L–1 melatonin treatment also delayed the increase in weight loss and the decrease in sensory parameter scores; retarded the decline of chlorophyll content; slowed the decline in antioxidant capacity by maintaining the content of carotenoids and ascorbic acid, as well as increasing the levels of total phenolics; and increased the content of individual and total glucosinolates in the lateral buds of baby mustard. These findings indicate that melatonin treatment is effective for maintaining the sensory and nutritional qualities of postharvest baby mustard.

Drought stress is a key factor limiting the growth and tuber yield of potatoes (Solanum tuberosum L.). Brassinosteroids (BRs) have been shown to alleviate drought stress in several plant species; however, little is known about the physiological and molecular mechanisms by which BRs enhance drought resistance in potatoes. Here, we characterized changes in the physiology and transcriptome of the tetraploid potato variety ‘Xuanshu-2′ in response to drought stress after 24-epibrassinolide (EBR) pretreatment. The abscisic acid (ABA) content, photosynthetic capacity, and the activities of antioxidant enzymes were increased; the intercellular CO2 concentration, relative conductivity, reactive oxygen species, malondialdehyde, proline, and soluble sugar content were decreased after EBR pretreatment compared with plants under drought stress. Transcriptome analysis revealed 1330 differently expressed genes (DEGs) involved in the response to drought stress after EBR pretreatment. DEGs were enriched in plant hormone signal transduction, starch and sucrose metabolism, circadian rhythm, flavonoid biosynthesis, and carotenoid biosynthesis. DEGs associated with the BR signaling and biosynthesis pathways, as well as ABA metabolic pathways were identified. Our findings provide new insights into the mechanisms by which BRs enhance the drought resistance of potatoes.

Effect of packaging baby mustard into bags of different color under light exposure on its visual quality and the content of chlorophyll, carotenoids, and glucosinolates at 20°C was investigated. Packaging with seven color bags under light exposure prolonged the shelf life, especially green (GB), blue (BB), and transparent (TB) bags with holes, and their shelf life was 1.7, 1.6, and 1.6 times that of the control, respectively. The GB and BB treatments delayed the deterioration of the sensory quality in baby mustard during storage. The BB and TB treatments not only increased chlorophyll and carotenoids content in baby mustard during storage but also enhanced the accumulation of glucosinolates by inhibiting their degradation, especially the BB treatment. Overall, the results demonstrate that the BB treatment is a promising technique for maintaining the postharvest quality of baby mustard.

This study investigated the effects of blanching and subsequent long-term frozen storage on the retention of health-promoting compounds and antioxidant capacity in frozen lateral buds of baby mustard. Results showed that all glucosinolates were well preserved during frozen storage, and 72.48% of total glucosinolate content was retained in the unblanched treatment group after 8 months, as were chlorophylls, carotenoids, ascorbic acid, total phenolics, soluble sugars, soluble proteins, and antioxidant capacity. The loss of nutritional qualities mainly occurred in the 1st month of frozen storage, and nutritional qualities in the unblanched treatment group were significantly better than those in the blanched treatment group during frozen storage. Blanching before freezing reduced contents of high-content glucosinolates and ascorbic acid, as well as antioxidant capacity levels. Therefore, we recommend using long-term frozen storage to preserve the quality of baby mustard to achieve annual supply, and freezing without blanching.