RT Journal Article
SR Electronic
T1 Ubiquitin Ligase SmDDA1b of Eggplant (<em>Solanum melongena</em>) Enhances Bacterial Wilt Resistance via SmNAC Degradation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.12.03.471130
DO 10.1101/2021.12.03.471130
A1 Yixi Wang
A1 Shuangshuang Yan
A1 Bingwei Yu
A1 Yuwei Gan
A1 Jiangjun Lei
A1 Changming Chen
A1 Zhangsheng Zhu
A1 Zhengkun Qiu
A1 Bihao Cao
YR 2021
UL http://biorxiv.org/content/early/2021/12/03/2021.12.03.471130.abstract
AB Bacterial wilt (BW) is a soil-borne disease that severely impacts plant growth and productivity globally. Ubiquitination plays a crucial role in disease resistance. Our previous research indicated that NAC transcription factor SmNAC negatively regulates BW resistance in eggplant (Solanum melongena). However, whether the ubiquitin/26S proteasome system (UPS) participates in this regulation is unknown.This study used SmNAC as a bait to screen eggplant cDNA library and obtained SmDDA1b, an E3 ubiquitin ligase. Subcellular location and bimolecular fluorescence complementation assays revealed that SmDDA1b could interact with SmNAC in the nucleus. The in vivo and in vitro ubiquitination experiments indicated that SmDDA1b can degrade SmNAC through UPS. However, the discovery of negative regulation of SmDDA1b expression by SmNAC showed that there was a negative feedback loop between SmNAC and SmDDA1b in eggplant.The SmDDA1b-overexpressed lines showed a higher BW resistance associated with high expression levels of salicylic acid (SA)-related genes and SA content than the wild-type lines. However, SmDDA1b-silencing lines showed the opposite results, indicating that SmDDA1b is a positive regulatory gene for BW resistance.This study provides a candidate gene that can enhance BW resistance in eggplants. In addition, it provides insight into a mechanism that promotes plant disease resistance via the SmDDA1b-SmNAC-SA pathway.