Low light caused by industrial development and environment change has become a limitation in crop production. This condition inhibits the petiole anthocyanin synthesis and even its tastes in purple cai-tai (Brassicarapa L. var. purpurea); however, the molecular basis of the inhibitory effects by low light on anthocyanin synthesis in purple cai-tai petiole is less reported. In this study, we performed an integrated analysis of transcriptomes and metabolisms to decipher key genes and/or metabolites that responsible for low light acclimation in a purple cai-tai cultivar, XH1. Results shows that anthocyanin is obviously repressed by low light treatment, and consistently the structural genes related to the anthocyanin biosynthesis pathway is significantly enriched in the list of differentially expressed genes according to both GO and KEGG analysis. Furthermore, the amounts of some metabolites related to anthocyanin are dramatically decreased under low light treatment, such as cyanindin 3-O-glucoside chloride, cyanindin O-syringic acid, and cyanidin 3-O-rutinoside. In addition, we found that five transcription factors in TCP gene family especially BrTCP15 is substantially downregulated by low light treatments. The expression pattern of BrTCP15 in response to low light treatment was further confirmed by qPCR. This study reports the inhibitory effects of the anthocyanin biosynthesis pathway and BrTCP15 by low light treatments, and extends our knowledge on regulatory mechanism of the anthocyanin biosynthetic pathway in response to low light in B. rapa L.

Pea sprouts, considered a nutritious and environmentally sustainable vegetable with significant cultivation prospects and market potential, face growth challenges due to salt stress. However, the underlying mechanisms associated with this stress have not been fully elucidated. To address this knowledge gap, we conducted a hydroponic study applying various concentrations of NaCl salt stress to pea sprouts. Systematic analysis was performed on key parameters including germination, plant height, biomass, and enzyme activity of pea sprouts under salt treatment. Our aim was to unravel the underlying mechanisms associated with the impact of salt stress on the growth of pea sprouts. Results revealed that salt treatment significantly inhibited the germination process of pea sprouts’ seeds, leading to a notable decrease in plant height and sprout yield. Salt stress induced an increase in MDA content, a decrease in chlorophyll content, and elevated relative conductivity. However, a low concentration of salt treatment enhanced SOD activity, suggesting the activation of oxidative stress resistance mechanisms in pea sprouts. Moreover, salt treatment exhibited an inhibitory effect on soluble protein content while promoting soluble sugar content in pea sprouts. Additionally, low-concentration salt treatment increased the crude fiber content of pea sprouts, while high-concentration salt treatment inhibited it. In summary, this study indicates that salt stress could cause physiological damage to pea sprouts, but pea sprouts may employ metabolic strategies to adapt to the low concentration of salt stress. These findings contribute to a deeper understanding of the physiological responses of pea sprouts to salt stress and provide valuable insights for its implementation of salt-tolerant cultivation.

Background: The escalating global salinization poses a significant threat to agricultural productivity, necessitating a thorough understanding of plant responses to high salinity. Pea sprouts (Pisum sativum), a nutrient-rich crop increasingly cultivated in salinized regions, serve as an ideal model for such investigations due to their rapid growth cycle and documented sensitivity to ionic stress. Methods: In order to understand the response of pea sprouts in physiological regulation, redox-metabolic adjustments, and transcriptome reprogramming under salt stress, we investigated the effects of high salt concentrations on the ascorbic acid–glutathione cycle, endogenous hormone levels, metabolite profiles, and gene expression patterns in it. Results: Our findings reveal early-phase antioxidant/hormonal adjustments, mid-phase metabolic shifts, and late-phase transcriptomic reprogramming of pea sprouts under salt conditions. In addition, a biphasic response in the ascorbic acid cycle was found, with initial increases in enzyme activities followed by a decline, suggesting a temporary enhancement of antioxidant defenses. Hormonal profiling indicated a significant increase in abscisic acid (ABA) and jasmonic acid (JA), paralleled by a decrease in indole acetic acid (IAA) and dihydrozeatin (DZ), underscoring the role of hormonal regulation in stress adaptation. Metabolomic analysis uncovered salt-induced perturbations in sugars, amino acids, and organic acids, reflecting the metabolic reconfiguration necessary for osmotic adjustment and energy reallocation. Transcriptomic analysis identified 6219 differentially expressed genes (DEGs), with a focus on photosynthesis, hormone signaling, and stress-responsive pathways, providing insights into the molecular underpinnings of salt tolerance. Conclusions: This comprehensive study offers novel insights into the complex mechanisms employed by pea sprouts to combat salinity stress, contributing to the understanding of plant salt tolerance and potentially guiding the development of salt-resistant crop varieties.