Drought stress is one of the most severe environmental factors that greatly restrict plant distribution and crop production. The molecular mechanisms underlying plant tolerance to drought stress are still not fully understood because of the complex nature of the response to drought stress.

Prof. YU Diqiu and his lab of Xishuangbanna Tropical Botanical Garden (XTBG) and other independent groups have shown that WRKY factors play important positive or negative roles in abiotic stress responses in Arabidopsis. However, few studies were focused on their function in drought stress.

Prof. YU Diqiu and his team isolated an acquired drought tolerance (adt) mutant with improved drought tolerance from a pool of WRKY-associated T-DNA insertion mutants. Further analysis revealed that a T-DNA, localized in the putative promoter region of WRKY57, caused elevated WRKY57 expression in acquired drought tolerance.

Both acquired drought tolerancet and WRKY57 transgenic plants displayed characteristics related to drought tolerance with elevation of their abscisic acid (ABA) contents and up-regulation expressive levels of stress-response genes (RD29A, ABA3, and NCED3).

Overall, their results indicated that activated expression of WRKY57 confers the adaption of Arabidopsis to drought tolerance by elevation of ABA levels and positively regulating the expression of stress-responsive genes. Their results may reveal a mechanism that plants evolve to adapt to drought tolerance. Establishment of WRKY57 functions will enable improvement of plant drought tolerance through gene manipulation approaches.

 The study entitled “Activated Expression of WRKY57 Confers Drought Tolerance in Arabidopsis” has been published online in Molecular Plant, doi: 10.1093/mp/sss080