AUTHOR=Yang Jingli , Wang Hanzeng , Zhao Shicheng , Liu Xiao , Zhang Xin , Wu Weilin , Li Chenghao 

TITLE=Overexpression Levels of LbDREB6 Differentially Affect Growth, Drought, and Disease Tolerance in Poplar

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 11 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.528550

DOI=10.3389/fpls.2020.528550

ISSN=1664-462X

ABSTRACT=The application of drought stress regulating transcription factors (TFs) offers a credible way to improve drought tolerance in plants. However, many drought resistant TFs always showed unintended adverse effects on plant growth or others. Few studies have been conducted in trees to evaluate and overcome the pleiotropic effects of drought tolerance TFs. Here, we report the dose dependent effect of Limonium bicolor LbDREB6 gene on its overexpression in Populus ussurensis. High- and moderate-level overexpression of LbDREB6 significantly increased drought tolerance in a dose dependent manner. However, the OE18 plants showed stunted growth under normal conditions, but also they were more sensitive to Marssonina brunnea infection than WT and OE14 plants. While, OE14 showed normal growth, and the pathogen tolerance of them was not significantly different from WT. Many stress-responsive genes were up-regulated in OE18 and OE14 compared with WT, especially for OE18 plants. Meanwhile, more pathogen tolerance related genes were down-regulated in OE18 compared with OE14 and WT plants. We achieved improving drought tolerance by adjusting the increased levels of exogenous DREB genes to avoid the occurrence of growth reduction and reduced disease tolerance.