A florigen family gene drives the reprogramming of soybean cortical cells into nodule stem cells

On June 23, the Innovation Team for Mechanistic Analysis and Design of High-Yield Traits in Soybean at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences (ICS-CAAS), revealed how functional divergence of the florigen family gene GmFT5b drives soybean root nodule formation. The findings were published online in Nature Communications.

Symbiotic nitrogen fixation between legumes and rhizobia is an important nitrogen source in agricultural ecosystems. It is vital for increasing soybean yield, reducing fertilizer use, and improving farmland ecology. However, the molecular mechanism by which rhizobial infection induces root cortical cells to reprogram and differentiate into nodule stem cells has remained unresolved.

The researchers focused on functional divergence within the soybean florigen gene family and its role in promoting nodulation through the reprogramming of root cortical cells into nodule stem cells. Functional analysis of the florigen homolog GmFT5b and its interacting protein GmFDL23 showed that rhizobia induce their expression in the root cortex. The two proteins form a functional complex that directly suppresses a negative regulator in the cortex, releasing stem cell regulators from repression. This drives cortical cells to reprogram into nodule stem cells and initiates nodule formation. The study expands the early regulatory network of soybean nodulation and provides new candidate targets for improving nodulation efficiency through molecular breeding.

Sun Huiyu, a doctoral student, and Zhang Xiaomei, an associate research professor, at ICS-CAAS are co-first authors. Research professor Fu Yongfu at ICS-CAAS is the corresponding author. The work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Agricultural Science and Technology Innovation Program of CAAS, and other programs.

Original paper: https://www.nature.com/articles/s41467-026-74688-4