MaWRKY76 enhances symbiotic nodulation and salt tolerance of nodulation by activating <i>NIN</i> in <i>Melilotus albus</i>

Shengsheng Wang; Bao Ao; Qi Yan; Fan Wu; Pan Xu; Zhen Duan; Yunyue Xiao; Yangyang Han; Yuncan Qu; Jiyu Zhang

doi:10.1016/j.jgg.2026.06.003

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MaWRKY76 enhances symbiotic nodulation and salt tolerance of nodulation by activating NIN in Melilotus albus

doi: 10.1016/j.jgg.2026.06.003

State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, Gansu 730020, China

Funds:

This work was supported by the National Natural Science Foundation of China (U23A200216, 32271752), Inner Mongolia Seed Industry Science and Technology Innovation Major Demonstration Project (2022JBGS0040), Central Government Guided Local Science and Technology Development Fund Project (24ZYQA047).

Received Date: 2026-03-27
Accepted Date: 2026-06-02
Rev Recd Date: 2026-05-30

Available Online: 2026-06-06

Abstract

Abstract

Legumes establish mutualistic symbiosis with rhizobia to facilitate biological nitrogen fixation. However, the genetic and molecular mechanisms of symbiotic nodulation regulated by salt stress remain largely unexplored. In this study, we identify that MaWRKY76 localizes to the nucleus and possesses transcriptional activation activity in Melilotus albus. MaWRKY76 expression is strongly induced under salt stress and upregulated during nodule formation. Transgenic hairy root composite plants overexpressing MaWRKY76 enhance salt tolerance by increasing antioxidant enzyme activity and alleviating oxidative damage. Furthermore, MaWRKY76 also promotes symbiotic nodulation by directly targeting the promoter region of NODULE INCEPTION (MaNIN), a master regulator of nodule development, and activating its expression. Under salt stress, MaWRKY76 overexpression plants enhance salt tolerance of nodulation by increasing nodule numbers and upregulating MaNIN expression, whereas knockdown of MaWRKY76 produces the opposite effect. Our findings reveal that MaWRKY76 functions as a transcriptional activator of NIN in legume nodulation signaling, and serves as a regulatory node to coordinate salt stress response with symbiotic nodulation.
- Melilotus albus,
- Symbiosis,
- Salt tolerance,
- Nodule development,
- MaWRKY76,
- MaNIN

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References

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