Temperature levels beyond an organism's optimal tolerance range are regarded as a major abiotic stress. Extreme high temperature disturbs cellular homeostasis and severely impairs plant growth and development. Worldwide, extensive agricultural losses are attributed to heat, often in combination with drought or other stresses. Thus, finding an effective strategy for protecting plant cells from damage caused by rapid and/or drastic changes in temperature is of particular importance for agricultural production.

Limited information is available regarding the exact function of specific WRKY transcription factors in plant responses to heat stress.

Prof. YU Diqiu of Xishuangbanna Tropical Botanical Garden (XTBG) and his colleagues analyzed the roles of WRKY25, WRKY26, and WRKY33, three types of group I WRKY proteins, in the regulation of resistance to heat stress by analyzing both potential upstream and downstream targets of these genes, and their loss-of-function and over-expression phenotypes.

The researchers suggest that these three regulators show partial redundancy in thermotolerance and regulate the cooperation between MBF1c (ethylene)-activated and Hsps-related signaling pathways that mediate responses to heat stress.

In addition, the results reveal that WRKY25, WRKY26, and WRKY33 positively regulate each other's expression during heat stress and play synergetic roles in thermotolerance in A. thaliana.

The study entitled “Arabidopsis thaliana WRKY25, WRKY26, and WRKY33 coordinate induction of plant thermotolerance” has been published in Planta: An International Journal of Plant Biology, 233(6):1237-1252. DOI:10.1007/s00425-011-1375-2

URL: http://www.springerlink.com/content/b1322lm181772q81/