Characterization of cis-elements in hormonal stress-responsive genes in Oryza sativa

Abstract

Phytohormones play a key role in plant growth and development. The process of plant’s perception and response to abiotic and biotic stresses is controlled mainly by the phytohormones which act as an endogenous messenger in the regulation of the plant’s status. They can be activated by different signaling pathways in response to environmental stresses. Plants respond to environmental stress through interaction of transcription factors with a handful of cis-regulatory elements (CREs). Some examples of cis elements include abscisic acid-responsive element (ABRE), G-box (CACGTG) element, and W-box. In order to investigate the effects of different hormonal stresses which have a key role in response to biotic and abiotic stresses in rice, microarray data was used. Of the available data, 931 genes revealed significant differences in response to different hormonal stresses such as auxin, cytokinin, abcisic acid, ethylene, salicylic acid, and jasmonic acid. The present results showed that 388 genes were up-regulated, and 543 genes were down-regulated. Most of the genes were up-regulated in response to Indole-3-acetic acid (IAA) hormone. Genes Ontology analysis revealed that they respond to various hormones involved in auxin- responsive genes, auxin-activated signaling pathway and cellular responses to environmental stimuli. G-box had the highest number of cis elements involved in hormonal stress and was regulated by auxin signaling and various stresses. Dehydrin was the only gene up-regulated in response to the six hormones. This gene can be activated in response to abiotic and biotic stresses. As such, dehydrin gene can be used in crop breeding programs to increase tolerance to different environmental stresses in various plant species.