Soybean NIMA-Related Kinase1 Promotes Plant Growth and Improves Salt and Cold Tolerance.

NEK (NIMA-related kinase) is known as a family of serine/threonine kinases which mainly participate in microtubule-related mitotic events in fungi, mammals and other eukaryotes. Our previous studies found that Arabidopsis NEK6 plays an important role in plant response to abiotic stress. We further investigated roles of the NEK family in soybean and found that at least eight members can respond to abiotic stresses. Among them, only GmNEK1, a novel NEK member which is distantly related to Arabidopsis NEK6, enhanced plant growth and promoted salt and cold tolerance in transgenic Arabidopsis plants. The growth of soybean plants harboring GmNEK1-overexpressing hairy roots under saline condition was also improved. A series of stress-related genes including RH3, CORI3 and ALDH10A8 were found to be up-regulated in GmNEK1-overexpressing Arabidopsis plants and soybean hairy roots. Moreover, soybean plants with GmRH3-overexpressing hairy roots exhibited increased salt tolerance, while soybean plants with GmRH3-RNAi (RNA interference) roots were more sensitive to salt stress than the wild-type plants. Our study uncovers a novel role for GmNEK1 in promoting plant adaptive growth under adverse conditions at least partially through up-regulation of GmRH3. Manipulation of these genes in soybean or other crops may improve growth and production under stress conditions.