Combined Transcriptomic and Metabolomic Analysis Reveals the Role of Phenylpropanoid Biosynthesis Pathway in the Salt Tolerance Process of Sophora alopecuroides

Abstract

Salt stress is the main abiotic stress that limits crop yield and agricultural development. Therefore, it is imperative to study the effects of salt stress on plants and the mechanisms through which plants respond to salt stress. In this study, we used transcriptomics and metabolomics to explore the effects of salt stress on Sophora alopecuroides. We found that salt stress incurred significant gene expression and metabolite changes at 0, 4, 24, 48, and 72 h. The integrated transcriptomic and metabolomic analysis revealed that the differentially expressed genes (DEGs) and differential metabolites (DMs) obtained in the phenylpropanoid biosynthesis pathway were significantly correlated under salt stress. Of these, 28 DEGs and seven DMs were involved in lignin synthesis and 23 DEGs and seven DMs were involved in flavonoid synthesis. Under salt stress, the expression of genes and metabolites related to lignin and flavonoid synthesis changed significantly. Lignin and flavonoids may participate in the removal of reactive oxygen species (ROS) in the root tissue of S. alopecuroides and reduced the damage caused under salt stress. Our research provides new ideas and genetic resources to study the mechanism of plant responses to salt stress and further improve the salt tolerance of plants.

Analysis of Phytohormone Signal Transduction in Sophora alopecuroides under Salt Stress

“…Meanwhile, SaTGA was initially upregulated under salt stress, but then downregulated, reaching its highest level at 4 h ( Figure 8 ). The expression of SaPAL , a key gene in SA biosynthesis, was upregulated at 4 h, 24 h, and 72 h under salt stress, but there was no significant ( p < 0.05) difference in its expression at 48 h compared with that of the control [ 4 ]. However, S. alopecuroides growth was stable for 48 h under salt stress, indicating that SA played a positive regulatory role in the response of S. alopecuroides to salt stress.…”

“…Tolerance of different crops to salt stress varies, indicating there may be different mechanism of action in response to salt stress [ 9 , 10 ]. Previous studies have shown that S. alopecuroides is able to maintain growth under high-salt stress, which suggests it has a high level of resistance [ 4 , 5 ]. In the current study, we further analyzed the role of phytohormone signal transduction pathways in the roots of S. alopecuroides under salt stress, which is of great significance in elucidating the mechanism involved in the response of S. alopecuroides to salt stress.…”

“…One promising factor is that plants have developed a series of abilities to resist salt stress during long-term evolution [ 3 ]. Differences in the environments of plants lead to differences in salt tolerance [ 3 , 4 ]. To successfully cultivate highly salt-tolerant crops, it is necessary to further explore the salt tolerance of highly resistant plants [ 4 ].…”

“…Differences in the environments of plants lead to differences in salt tolerance [ 3 , 4 ]. To successfully cultivate highly salt-tolerant crops, it is necessary to further explore the salt tolerance of highly resistant plants [ 4 ]. Sophora alopecuroides is a legume plant that can adapt to harsh natural environments and exhibits strong stress resistance [ 4 , 5 ].…”

“…To successfully cultivate highly salt-tolerant crops, it is necessary to further explore the salt tolerance of highly resistant plants [ 4 ]. Sophora alopecuroides is a legume plant that can adapt to harsh natural environments and exhibits strong stress resistance [ 4 , 5 ]. Currently, there are few studies on the effects of salt stress on S. alopecuroides and on the mechanism of its response to salt stress.…”