Arabidopsis E3 Ubiquitin Ligases PUB22 and PUB23 Negatively Regulate Drought Tolerance by Targeting ABA Receptor PYL9 for Degradation

International Journal of Molecular Sciences

Ming Li¹  Linlin Zhao²  Wenhui Zhang²  Xueyong Li³  Syed Adeel Zafar³  Jingjing Fang³  Jinfeng Zhao³  Ming Zhang³ 

[1] College of Agriculture, Northeast Agricultural University, Harbin 150030, China;College of Life Sciences, Liaocheng University, Liaocheng 252059, China;National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China;

关键词: ABA receptor;    cell-free degradation assay;    degradation;    drought tolerance;    protein extract;    U-box E3 Ubiquitin ligases;   

DOI  :  10.3390/ijms18091841

来源: DOAJ

【 摘 要 】

Drought causes osmotic stress and rapidly triggers abscisic acid (ABA) accumulation in plants. The roles of various ABA receptors in drought tolerance and molecular mechanisms regulating ABA receptor stability needs to be elucidated. Here, we report that Arabidopsis plants overexpressing PYL9, one of the 14 pyrabactin resistance (PYR)/pyrabactin resistance-like (PYL)/regulatory component of ABA receptors (RCAR) family ABA receptors, gained drought tolerance trait. Osmotic stress induced accumulation of the PYL9 protein, which was regulated by the 26S proteasome. PYL9 interacted with two highly homologous plant U-box E3 ubiquitin ligases PUB22 and PUB23. In the cell-free degradation assay, the degradation of GST-PYL9 was accelerated in protein extract from plants overexpressing PUB22 but slowed down in protein extract from the pub22 pub23 double mutant. The in vivo decay of Myc-PYL9 was significantly reduced in the pub22 pub23 double mutant as compared with the wild-type. Additionally, PUB22 also interacted with other ABA receptors such as PYL5, PYL7 and PYL8. Considering the improved drought tolerance in the pub22 pub23 double mutant in previous studies, our results suggest that PUB22 and PUB23 negatively regulate drought tolerance in part by facilitating ABA receptors degradation.

【 授权许可】

Unknown