Homeobox genes as potential candidates for crop improvement under abiotic stress

Abstract

Understanding the molecular basis of plant responses to the major abiotic stresses such as drought and salinity is very important for the biotechnological application of stress adaptation for crop improvement. In this context, thousands of stress-responsive genes have been identified and a few of them have been functionally characterized. Some of them have been proposed as suitable targets for genetic engineering in order to impart stress tolerance in plants. Amidst numerous genes analyzed, transcription factors are considered to be very good targets for studying the molecular mechanisms of abiotic stress response as they singularly or in conjunction regulate the expression of many downstream target genes. Among the various transcription factor encoding genes, homeobox genes, which are well known to be involved in diverse aspects of development, have also recently been implicated in abiotic stress responses. Through various overexpression and mutant studies, the versatility of homeobox genes in plants has been revealed. There are evidences where these genes have been found to confer stress tolerance in plants. This review highlights the importance of homeobox genes in abiotic stress responses and their potential for engineering stress tolerance for crop improvement.