RNA-seq analysis reveals the role of a small GTP-binding protein, Rab7, in regulating clathrin-mediated endocytosis and salinity-stress resistance in peanut

Abstract

Small GTP-binding proteins, Rab7, are known to be responsive to abiotic stresses in plants, but the molecular mechanism is poorly understood. To investigate how AhRab7 increases resistance to salinity stress in peanut, this study compared a transgenic genotype (S5) that overexpressed the AhRab7 gene and that had high salinity resistance with a non-transgenic genotype (S7) that had low salinity resistance. Digital gene expression (DGE) sequencing was performed with leaves of S5 and S7 before and after salinity-stress treatment. In total, 2697 differentially expressed genes (DEGs) were identified between S5 and S7, and KEGG enrichment analyses showed that the DEGs are involved pathways including endocytosis, lysosome, hormone signaling, phosphatidylinositol signaling, calcium, and others. Among them, 164 were differentially regulated after salinity-stress treatment. Of 164 DEGs, 110 were responsive to salinity stress in S5 and/or S7. The 110 DEGs included genes that encode the following kinds of transcription factors and proteins known to be involved in resistance to salinity stress: WRKY, NAC, MYM-type zinc finger, late embryogenesis abundant proteins, lipid transfer protein, 1-cys peroxiredoxin, aquaporin, oleosin, and others. AhRab7 gene might mediate signaling pathways including phosphatidylinositol, calcium, abscisic acid, etc., and then regulate the expression of transcription factors and downstream genes for ROS scavenging in peanut. The results of this study will be useful for further investigations of the mechanism underlying the role of the AhRab7 gene in resistance to salinity stress in peanut.