GmNMH7 Inhibits Root and Nodule Development in Soybean

As an important food crop and oil crop, soybean (Glycine max) is capable of nitrogen-fixing by root nodule. Previous studies showed that GmNMH7, a transcription factor of MADS-box family, is associated with nodule development. However, its specific function is unknown. Researchers Ma Wen-ya and Liu Wei from the Chinese Academy of Agricultural Sciences recently found that GmNMH7 is specifically expressed in root and nodule.

Analysis also found that the expression pattern of GmNMH7 was similar to several genes involved in the development of nodules after rhizobia inoculation. The earlier expression peak of GmNMH7 compared to the other genes indicates that the gene is related to the NF (nod factor) signaling pathway and functions in the early development of nodule.

Overexpression of GmNMH7 in hairy roots significantly reduced the nodule number and the root length. Moreover, the overexpression of GmNMH7 reduced the content of abscissic acid, and increased the content of gibberellins in the transgenic hairy roots.

This study concludes that GmNMH7 participates in the NF signaling pathway and negatively regulates nodulation probably through regulating the content of gibberellins.

For more on this study, read the article in Journal of Integrative Agriculture.