Tomato fruit consumption is influenced by flavor and nutrient quality. In the present study, we investigate the impact of water saving irrigation (WSI) as a pre-harvest management on flavor and nutrient quality of tomato fruit. Our results demonstrate that WSI-treated tomato fruit exhibited improved sensory scores as assessed by a taste panel, accompanied by elevated levels of SlGLK2 expression, sugars, acids, and carotenoid contents compared to non-treated fruit. Notably, WSI treatment significantly enhanced the development of chloroplast and plastoglobulus in chromoplast, which served as carotenoid storage sites and upregulated the expression of carotenoid biosynthetic genes. Furthermore, integrated transcriptome and metabolome analysis revealed heightened expression of sugar and flavonoid metabolism pathways in WSI-treated tomato fruit. Remarkably, the master regulator SlMYB12 displayed a substantially increased expression due to WSI. These findings suggest that WSI is an effective and sustainable approach to enhance the pigments metabolism and storage capacity as well as the organoleptic characteristics and nutritional value of tomato fruit, offering a win-win solution for both water conservation and quality improvement in agro-food production.

番茄八氢番茄红素合成酶(SlPSY1)作为类胡萝卜素生物合成途径的关键限速酶,直接影响果实中类胡萝卜素的积累.为探究SlPSY1基因的转录调控机制,通过克隆SlPSY1基因启动子序列,构建pSlPSY1pro-AbAi诱饵载体,并将诱饵载体转化至酵母细胞中获得诱饵酵母菌株.利用番茄混合组织酵母杂交cDNA文库进行酵母单杂交筛库试验,筛选得到AP2/ERF家族转录因子SlJERF1和10个未知功能蛋白.后续克隆SlJERF1基因序列,构建pGADT7-SlJERF1重组载体,通过酵母单杂交点对点对SlJERF1进行分子验证,结果显示在金担子素(AbA)浓度为150 ng·mL-1的条件下,对照组酵母不能正常生长,而试验组酵母能正常生长,表明SlJERF1与SlPSY1基因启动子存在互作.这一结果为进一步拓展类胡萝卜素合成调控网络提供了重要的理论依据.

The plant hormone ethylene is essential for climacteric fruit ripening, although it is unclear how other phytohormones and their interactions with ethylene might affect fruit ripening. Here, we explored how brassinosteroids (BRs) regulate fruit ripening in tomato (Solanum lycopersicum) and how they interact with ethylene. Exogenous BR treatment and increased endogenous BR contents in tomato plants overexpressing the BR biosynthetic gene SlCYP90B3 promoted ethylene production and fruit ripening. Genetic analysis indicated that the BR signaling regulators Brassinazole-resistant1 (SlBZR1) and BRI1-EMS-suppressor1 (SlBES1) act redundantly in fruit softening. Knocking out SlBZR1 inhibited ripening through transcriptome reprogramming at the onset of ripening. Combined transcriptome deep sequencing and chromatin immunoprecipitation followed by sequencing identified 73 SlBZR1-repressed targets and 203 SlBZR1-induced targets involving major ripening-related genes, suggesting that SlBZR1 positively regulates tomato fruit ripening. SlBZR1 directly targeted several ethylene and carotenoid biosynthetic genes to contribute to the ethylene burst and carotenoid accumulation to ensure normal ripening and quality formation. Furthermore, knock-out of Brassinosteroid-insensitive2 (SlBIN2), a negative regulator of BR signaling upstream of SlBZR1, promoted fruit ripening and carotenoid accumulation. Taken together, our results highlight the role of SlBZR1 as a master regulator of tomato fruit ripening with potential for tomato quality improvement and carotenoid biofortification.

Plastids are a group of diverse organelles with conserved carotenoids synthesizing and sequestering functions in plants. They optimize the carotenoid composition and content in response to developmental transitions and environmental stimuli. In this review, we describe the turbulence and reforming of transcripts, proteins, and metabolic pathways for carotenoid metabolism and storage in various plastid types upon organogenesis and external influences, which have been studied using approaches including genomics, transcriptomics, proteomics, and metabonomics. Meanwhile, the coordination of plastid signaling and carotenoid metabolism including the effects of disturbed carotenoid biosynthesis on plastid morphology and function are also discussed. The “omics” insight extends our understanding of the interaction between plastids and carotenoids and provides significant implications for designing strategies for carotenoid-biofortified crops.

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.

Background: Tomato is one of the most important vegetables as well as a main dietary source of carotenoids. As a diverse kind of phytochemicals and main sources of natural pigments, carotenoids and carotenoid-derived vol-atile compounds are associated with the sensory, nutritional and flavor quality of tomato products. Scope and approach: The current review summarizes the biosynthetic and catabolic pathways of carotenoids, as well as carotenoid biofortification in tomato products throughout the whole agro-food chain, including breeding/selection for suitable tomato varieties, pre-harvest managements, harvesting, and postharvest handlings.Key findings and conclusions: We recommend the integrative and sustainable management of tomato industry along the whole agro-food chain to fight carotenoid deficiency worldwide starting from breeding/selection carotenoids-biofortified tomato cultivars either via classic hybrid, molecular mark assisted breeding, or genetic engineering and genome editing approach, followed by suitable cultivation methods such as deficit irrigation, control of environmental conditions in pre-harvest production period. Meanwhile, harvesting at the proper stage of maturity and appropriate postharvest handlings including chemical regulation, optimum storage conditions, and processing methods during postharvest period can also maximize carotenoid retention. Considering that both fresh and processed tomatoes serve as major dietary sources of carotenoid, effective carotenoid biofortification in tomato products along the whole agro-food chain is essential in providing consumers carotenoid-enriched tomato on the eve of a new era in food fortification, contributing to sustainable tomato industry as well as human nutrition and potential health benefits.

Chinese kale (Brassica oleracea var. alboglabra) is rich in carotenoids, and neoxanthin is one of the most important carotenoids in Chinese kale. In this study, the function of the neoxanthin synthase gene (BoaNXS) in Chinese kale was investigated. BoaNXS, which had a 699-bp coding sequence, was cloned from the white flower cultivar of Chinese kale and was expressed in all developmental stages and organs of Chinese kale; its expression was highest in young seeds. The subcellular localization indicated that BoaNXS was localized in the chloroplast. BoaNXS-overexpressed plants were obtained via Agrobacterium-mediated transient overexpression methodology, and the gene overexpression efficiencies ranged from 2.10- to 4.24-fold. The color in the leaves of BoaNXS-overexpressed plants changed from green to yellow-green; the content of total and individual carotenoids, such as neoxanthin, violaxanthin, and lutein, was significantly increased, and the expression levels of most carotenoid biosynthetic genes were notably increased. These findings indicated that BoaNXS is of vital importance in carotenoid biosynthesis in Chinese kale and could be used as a candidate gene for enriching the carotenoid accumulation and color of Chinese kale and other Brassica vegetables.

The effect of light exposure on sensory quality, health-promoting phytochemical contents, and antioxidant capacity in the lateral buds of baby mustard plants was investigated at ambient storage temperature (20 degrees C). The results showed that light exposure (36 imol m(-2 )S(-1)) during post-harvest storage significantly prolonged shelf life (more than 1.75-fold), delayed the weight loss and the decrease of firmness. Light treatments also enhanced chlorophyll and carotenoid contents, and retarded declines in contents of soluble sugars, ascorbic acid, flavonoids and glucosinolates, as well as antioxidant capacity. The quality of baby mustard plants receiving 24 h daily light treatment was superior to those in plants receiving 12 h treatment and constant darkness at 20 degrees C. These findings indicate that light exposure, especially 24 h treatment, is an effective method of prolonging shelf life and maintaining sensory and nutritional qualities in baby mustard plants stored at ambient temperature.

Carotenoids are organic pigments that play an important role in both plant coloration and human health; they are a critical subject in molecular breeding due to growing demand for natural molecules in both food and medicine. In this study, we focus upon characterizing BoaCRTISO , the carotenoid isomerase gene before the branch of the carotenoid biosynthetic pathway, which is expressed in all organs and developmental stages of Chinese kale, and BoaCRTISO, which is located in the chloroplast. The expression of BoaCRTISO is induced by strong light, red and blue combined light, and gibberellic acid treatment, but it is suppressed by darkness and abscisic acid treatment. We obtained BoaCRTISO -silenced plants via virus-induced gene silencing technology, and the silence efficiencies ranged from 52 to 77%. The expressions of most carotenoid and chlorophyll biosynthetic genes in BoaCRTISO -silenced plants were downregulated, and the contents of carotenoids and chlorophyll were reduced. Meanwhile, BoaCRTISO -silenced plants exhibited phenotypes of yellowing leaves and inhibited growth. This functional characterization of BoaCRTISO provides insight for the biosynthesis and regulation of carotenoid in Chinese kale.

以白花芥蓝‘四季粗条’为材料克隆了Boa DFR基因,Gen Bank登录号为MT472647,CDS序列长为1 158 bp,编码385个氨基酸,与甘蓝型油菜、甘蓝和白菜等具有高度同源性。Boa DFR表达水平在芥蓝不同发育时期、不同器官中存在显著差异,随植株发育总体呈现先下降后上升的趋势,在幼嫩种子中表达量最高。芥蓝原生质体的亚细胞定位结果显示Boa DFR定位在细胞核上。构建了农杆菌介导的芥蓝瞬时过表达体系,将Boa DFR转入白花芥蓝‘四季粗条’和黄花芥蓝‘福州黄花’中,发现Boa DFR在两种芥蓝中均高水平表达,转基因植株叶片颜色明显变紫,花青素苷显著积累,总含量最高达461.43μg·g-1 FW,而野生型和转空载体芥蓝叶片中几乎检测不到花青素苷。通过HPLC在转基因植株叶片中共检测到8种花青素苷,均为矢车菊花青素苷,其中矢车菊–3–阿魏酰–丙二酰–槐糖苷–5–葡萄糖苷占比最高。

The experiment used the ‘Sijicutiao’ mustard sterile seedlings as the material, firstly constructed the BoaZDS subcellular localization vector with the cloned BoaZDS gene, and extracted the plasmid, then separated the Chinese kale leaf protoplast by enzymatic hydrolysis. After purification, the BoaZDS gene was transiently transformed, and then the position of the BoaZDS gene was observed under a fluorescence microscope. The results showed that the BoaZDS gene was localized in the chloroplast, which was consistent with the predicted results of bioinformatics software. The results provide a basis for studying the function of the ZDS gene in Chinese kale.

The carotenoid isomerase gene (BoaCRTISO) of Chinese kale was targeted and edited using the CRISPR/Cas9 system in the present study. The results showed a high mutation rate (81.25%), and 13 crtiso mutants were obtained. Only two types of mutations, insertions and replacements, were found. Both the total and individual carotenoid and chlorophyll concentrations of the biallelic and homozygous mutants were reduced, and the total levels declined by 11.89-36.33%. The color of the biallelic and homozygous mutants changed from green to yellow, likely reflecting a reduction in the color-masking effect of chlorophyll on carotenoids. The expression levels of most carotenoid and chlorophyll biosynthesis-related genes, including CRTISO, were notably lower in the mutants than in the WT plants. In addition, the functional differences between members of this gene family were discussed. In summary, these findings indicate that CRISPR/Cas9 is a promising technique for the quality improvement of Chinese kale and other Brassica vegetables.

Neoxanthin synthase (NXS) is an important enzyme in carotenoid biosynthesis. Here, the BoaNXS gene was cloned from yellow flower Chinese kale, and preformed for bioinformatics analysis. The BoaNXS gene contains an open reading frame of 699 bp that encodes a 232 - amino acid protein with a calculated molecular mass of 25.52 kD and an isoelectric point (pI) of 9.6. Subcellular localization predicted that the BoaNXS was in the chloroplast. The functional domain of the BoaNXS protein contains DUF4281 Super family. Homology analysis indicates that the NXS protein is apparently conserved during plant evolution, and BoaNXS is most closely related to Brassica napus, and B. oleracea var. oleracea. The findings of the present study provide a theoretical basis for the elucidation of NXS gene function in Chinese kale.

Abstract Chinese kale variety ‘Sijicutiao’ was used as the plant material. Chinese kale seedlings were treated by different light qualities, light intensities and phytohormones, and the expression of ζ-carotene desaturase gene (BoaZDS) was analyzed. The results showed that red & blue light significantly promoted the expression of BoaZDS gene, peaked at 6 h and the expression level was 2.33 folds than that of the control. Blue light also induced the expression of BoaZDS gene in the late stage (72 h). Strong light had a significant effect on BoaZDS gene expression, peaked at 24 h and the expression level was 5.64 folds than that of the control, whereas weak light inhibited the BoaZDS gene expression. Abscisic acid and salicylic acid induced the expression of BoaZDS gene, and expression patterns were bimodal. Both methyl jasmonate and gibberellin acid inhibited the expression of the BoaZDS gene. The results provided a basis for further study on the regulation mechanism of BoaZDS gene.

Chinese kale (Brassica oleracea var. alboglabra) has high nutritional value. This study investigated the contents of glucosinolates, antioxidants (chlorophylls, carotenoids, vitamin C, and total phenolics), and antioxidant capacity in five organs from six varieties of Chinese kale. The highest concentrations of individual and total glucosinolates were in the roots and inflorescences, respectively. The highest levels of antioxidants and antioxidant capacity were in inflorescences and leaves. Plant organs played a predominant role in glucosinolate and antioxidant accumulation. Glucoiberin, glucoraphanin, and glucobrassicin, the main anticarcinogenic glucosinolates, could be enhanced simultaneously because of their high positive correlations. The relationship between glucosinolates and antioxidant capacity indicated that glucobrassicin might contribute to the total antioxidant capacity. These results provide useful information related to consumption, breeding of functional varieties, and use of the non-edible organs of Chinese kale.