Biotech Updates

Regulator of Symbiotic Nodulation in Lotus Found

August 8, 2018

During the establishment of rhizobia‐legume symbiosis, the cytokinin receptor LHK1 (Lotus Histidine Kinase 1) is important for nodule formation. However, the mechanism on how cytokinin signaling regulates symbiosis remains unknown. To learn more about this, researchers led by Kai Cai from Huazhong Agricultural University in China studied the LHK1-interacting protein in lotus (Lotus japonica), LjCZF1.

LjCZF1 is a C3HC4‐type RING finger protein that is highly conserved in plants. LjCZF1 specifically interacted with LHK1 in several assays conducted in tobacco. Expression of LjCZF1 was upregulated significantly after inoculation with rhizobia. The generated CRISPR-Cas9 LjCZF1-knockout mutant lotus plants exhibited significantly reduced number of infection threads and nodules. On the other hand, transgenic plants overexpressing LjCZF1 exhibited increased numbers of infection threads and nodules.

These results suggest that LjCZF1 is a positive regulator of symbiotic nodulation.

For more information, read the article in Journal of Integrative Plant Biology.