ABSTRACT
State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy and Yangling Branch of China Wheat Improvement Center, Northwest A&F University, Yangling 712100, Shaanxi, China.
* Corresponding author: sweining2002@yahoo.com
Abiotic factors such as drought, salinity, low and high temperature, nutrient defi ciency, and UV radiation greatly affect the growth and development of plants. It is estimated that > 50% of average annual yield loss of major crops is caused by abiotic stress (Arzani 2008). Plants are sessile and exposed to multiple stresses at different growth stages with series of metabolic, morphological, physiological and molecular changes (Wang et al. 2001). Plants perceive stress and show adaptive response to various abiotic and biotic stresses. Stress tolerance in plants is generally of very complex nature with multiple genes involved in regulatory networks. Such response to tolerate or resist abiotic stress involves many biochemical pathways mediated by genes which are in turn regulated by transcription factors. Transcription factors (TF) are protein complexes that bind to specifi c cis-acting promoter elements thereby activating or repressing the transcriptional rates of their target genes. These TFs are usually multigene families and individual members within a family often respond differently to various stress conditions. Alternatively, different stress responsive genes may share the same TFs and activate similar cellular responses like stomatal closure, accumulation of stress proteins and anti-oxidants (Bohnert et al. 2001). A range of transcription factors like ERF, NAC, DREB and WRKY are involved in abiotic stress response in plants.
