The NMN Module Conducts Nodule Number Orchestra

Zhijuan Wang; Lixiang Wang; Yongliang Wang; Xia Li

doi:10.1016/j.isci.2020.100825

The NMN Module Conducts Nodule Number Orchestra

iScience. 2020 Feb 21;23(2):100825. doi: 10.1016/j.isci.2020.100825. Epub 2020 Jan 9.

Authors

Zhijuan Wang¹, Lixiang Wang², Yongliang Wang¹, Xia Li³

Affiliations

¹ State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China.
² State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China; Key Laboratory of Plant Stress Biology, School of Life Sciences, Henan University, Kaifeng, China.
³ State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, P.R. China. Electronic address: xli@mail.hzau.edu.cn.

Abstract

Legumes control nodule number through nodulation and autoregulation of nodulation (AON) pathways. Nodule Inception (NIN) is essential for rhizobial infection and nodule organogenesis in legumes. The GmNINa-miR172c-NNC1 (NMN) module, which consists of two positive regulators, GmNINa and miR172c, and a suppressor, NNC1, integrates both pathways. GmNINa activates miR172c to downregulate NNC1, leading to nodulation, while NNC1 inhibits miR172c expression, forming a negative feedback loop. GmNINa and NNC1 interact with each other and antagonistically fine-tune GmRIC1/RIC2 expression, turning AON on and off. Conversely, activation of AON inhibits GmNINa and miR172c expression, thereby reducing their inhibitory effects on NNC1 to attenuate both nodulation signaling and AON. The NMN module functions not only as an "accelerator" of the nodulation signal to promote nodulation but also as a "brake" on the signal by activating AON to orchestrate nodule number.

Keywords: Interaction of Plants with Organisms; Plant Biology; Plant Genetics.

Publication types

Review