Cloning and Characterization of Two Novel Genes Related to Stress Responses from Peanut (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) is an economic crop cultivated in tropical and subtropical regions around the world. The objective of the study was to clone highly expressed genes from peanut seed and analyze their functions. Two full-length cDNA sequences were cloned by PCR according to ESTs in the GenBank database of developing peanut seed. They were a GSL (gibberellin stimulated-like proteins) gene encoding 267 bp ORF named AhGSL1, and a SNARE11 gene encoding a 675 bp ORF named AhSNARE11. Transgenic overexpressing lines of Arabidopsis were generated and preliminary analysis showed that these two genes were related to abiotic stress responses. In low temperature stress conditions, overexpression of AhGSL1 inhibited root growth of Arabidopsis seedlings in transgenic plants compared with wild type. The qRT-PCR analysis revealed that under low temperature treatment, expressions of some gibberellin-related genes in transgenic Arabidopsis were altered. Overexpression of AhSNARE11 enhanced sensitivity to ABA and salt stress in transgenic lines during the early post-germination growth stages. Overexpression of AhSNARE11 also conferred drought tolerance to transgenic Arabidopsis. The qRT-PCR analysis revealed that after drought treatment, the mRNA levels of RD22, ABF3, NCED3 and CYP707A3 in Arabidopsis were more up-regulated in one-week-old seedlings of transgenic lines compared with those in wild type, indicating that AhSNARE11 may involved in ABA biosynthesis and signaling.