J Integr Plant Biol. ›› 2024, Vol. 66 ›› Issue (2): 176-195.DOI: 10.1111/jipb.13612

• Abiotic Stress Responses • Previous Articles     Next Articles

IbNIEL-mediated degradation of IbNAC087 regulates jasmonic acid-dependent salt and drought tolerance in sweet potato

Xu Li1,2†, Zhen Wang1†, Sifan Sun1†, Zhuoru Dai1, Jun Zhang1,2, Wenbin Wang1, Kui Peng1, Wenhao Geng1,2, Shuanghong Xia1, Qingchang Liu1, Hong Zhai1, Shaopei Gao1, Ning Zhao1, Feng Tian3, Huan Zhang1,2* and Shaozhen He1,2*   

  1. 1. Key Laboratory of Sweet Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis & Utilization and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Agronomy & Biotechnology, China Agricultural University, Beijing 100193, China;
    2. Sanya Institute of China Agricultural University, Sanya 572025, China;
    3. State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Key Laboratory of Biology and Genetic Improvement of Maize, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China
    These authors contributed equally to this work.
    *Correspondences: Huan Zhang (zhanghuan1111@cau.edu.cn); Shaozhen He (sunnynba@cau.edu.cn, Prof. He is fully responsible for the distribution of all materials associated with this article)
  • Received:2023-08-12 Accepted:2024-01-08 Online:2024-01-31 Published:2024-02-01

Abstract: Sweet potato (Ipomoea batatas [L.] Lam.) is a crucial staple and bioenergy crop. Its abiotic stress tolerance holds significant importance in fully utilizing marginal lands. Transcriptional processes regulate abiotic stress responses, yet the molecular regulatory mechanisms in sweet potato remain unclear. In this study, a NAC (NAM, ATAF1/2, and CUC2) transcription factor, IbNAC087, was identified, which is commonly upregulated in salt- and drought-tolerant germplasms. Overexpression of IbNAC087 increased salt and drought tolerance by increasing jasmonic acid (JA) accumulation and activating reactive oxygen species (ROS) scavenging, whereas silencing this gene resulted in opposite phenotypes. JA-rich IbNAC087-OE (overexpression) plants exhibited more stomatal closure than wild-type (WT) and IbNAC087-Ri plants under NaCl, polyethylene glycol, and methyl jasmonate treatments. IbNAC087 functions as a nuclear transcriptional activator and directly activates the expression of the key JA biosynthesis-related genes lipoxygenase (IbLOX) and allene oxide synthase (IbAOS). Moreover, IbNAC087 physically interacted with a RING-type E3 ubiquitin ligase NAC087-INTERACTING E3 LIGASE (IbNIEL), negatively regulating salt and drought tolerance in sweet potato. IbNIEL ubiquitinated IbNAC087 to promote 26S proteasome degradation, which weakened its activation on IbLOX and IbAOS. The findings provide insights into the mechanism underlying the IbNIEL-IbNAC087 module regulation of JA-dependent salt and drought response in sweet potato and provide candidate genes for improving abiotic stress tolerance in crops.

Key words: abiotic tolerance, IbNAC087, IbNIEL, JA, sweet potato

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