부산대학교 도서관

Abiotic stresses induce various physiological changes, including growth inhibition, that result in stress tolerance in plants. ZPT2-related proteins with two Cys2/His2-type zinc-finger motifs and an ERF-associated amphiphilic repression (EAR) motif are thought to function as transcriptional repressor under various stress conditions. We analyzed the function of the two Arabidopsis ZPT2-related genes that were induced by osmotic stress and ABA: AZF1 and AZF2. The nuclear localization of these two proteins was constantly observed in the roots, and the accumulation of AZF2 was clearly detected in the nuclei of leaf cells under stress conditions. The overexpression of AZF1 and AZF2 caused severe damage to plant growth and viability. Transcriptome analyses of the transgenic plants demonstrated that AZF1 and AZF2 repressed various genes that were downregulated by osmotic stress and ABA treatment. Moreover, many auxin-related genes were commonly downregulated in the plants, and most of them were small auxin-up RNAs (SAURs). These results indicate that AZF1 and AZF2 function as transcriptional repressors that are involved in the inhibition of plant growth under abiotic stress conditions.