Transcriptomic and metabolomic analysis reveals the role of CoA in the salt tolerance of Zygophyllum spp

Abstract

AbstractBackgroundZygophyllumis an important medicinal plant, with notable properties such as resistance to salt, alkali, and drought, as well as tolerance of poor soils and shifting sand. However, the response mechanism ofZygophyllumspp. to abiotic stess were rarely studied.ResultsHere, we aimed to explore the salt-tolerance genes ofZygophyllumplants by transcriptomic and metabolic approaches. We choseZ. brachypterum,Z. obliquumandZ. fabagoto screen for salt tolerant and sensitive species. Cytological observation showed that both the stem and leaf ofZ. brachypterumwere significantly thicker than those ofZ. fabago.Then, we treated these three species with different concentrations of NaCl, and found thatZ. brachypterumexhibited the highest salt tolerance (ST), whileZ. fabagowas the most sensitive to salt (SS). With the increase of salt concentration, the CAT, SOD and POD activity, as well as proline and chlorophyll content in SS decreased significantly more than in ST. After salt treatment, the proportion of open stomata in ST decreased significantly more than in SS, although there was no significant difference in stomatal number between the two species. Transcriptomic analysis identified a total of 11 overlapping differentially expressed genes (DEGs) in the leaves and roots of the ST and SS species after salt stress. Two branched-chain-amino-acid aminotransferase (BCAT) genes among the 11 DEGs, which were significantly enriched in pantothenate and CoA biosynthesis, as well as the valine, leucine and isoleucine biosynthesis pathways, were confirmed to be significantly induced by salt stress through qRT-PCR. Furthermore, overlapping differentially abundant metabolites showed that the pantothenate and CoA biosynthesis pathways were significantly enriched after salt stress, which was consistent with the KEGG pathways enriched according to transcriptomics.ConclusionsIn our study, transcriptomic and metabolomic analysis revealed that BCAT genes may affect the pantothenate and CoA biosynthesis pathway to regulate the salt tolerance ofZygophyllumspecies, which may constitute a newly identified signaling pathway through which plants respond to salt stress.