Abstract:
Soil salinity is an abiotic stress factor that limits global agricultural output. Common bean is an important protein source in developing countries, however sensitive to salinity. To understand the underlying mechanism of salt stress responses, transcrip tomics, metabolomics, and ionomics analyses were performed on both salt-tolerant and susceptible common bean genotypes under saline conditions. Transcriptomics revealed enhanced photosynthesis together with active carbon and amino acid metabolism in the tolerant genotype. Metabolomics revealed increased carbohydrate and amino acid metabolism in the tolerant genotype. Ion content comparison indicated that the tol erant genotype blocked the accumulation of Na+ in the leaves. The results of this omics study have demonstrated the differences in contrasting genotypes and provided information on the novel mechanisms salt tolerance to pinpoint genes with high po tential for functional analyses. Stress-related carbohydrate metabolism is a dynamic network and disruptions in this system can have negative effects on tolerance. Su crose phosphate synthase (SPS) enzymes operate in the sucrose synthesis pathway and have significant roles in sugar metabolism. This study has focused on the function of SPS homolog, pvSPS4, in the roots of salt-tolerant common bean under salt stress. Composite common bean plants with pvSPS4 knockdown roots exhibited sensitivity to salinity. Disturbed root carbohydrate and ion balance resulted in a reduction in photosynthesis together with osmoregulation and antioxidant capability. These results indicate that pvSPS4 is an important gene for carbohydrate balance regulation in the salt-stress response in the common bean root tissues.
