Overexpression of a glycine-rich protein gene in Lablab purpureus improves abiotic stress tolerance

Glycine-rich protein (GRP) is involved in the response to abiotic and biotic stresses in plants. A novel GRP gene in Lablab purpureus has been identified. The cDNA of LpGRP was obtained from an SSH library constructed with root tissues of L. purpureus MEIDOU 2012 by waterholding for 10 days. The function of LpGRP was also evaluated in Arabidopsis. The cDNA of LpGRP has 555 bp and encodes a 184-amino acid protein. LpGRP was induced by drought and improved tolerance to abiotic stress. In LpGRP overexpressing Arabidopsis, the tolerance of transgenic seedlings to drought and salt was improved, and transgenic seeds showed insensitivity to both ABA and NaCl. The insensitivity to ABA indicated that there was crosstalk between LpGRP and ABA-responsive genes. These results indicated that LpGRP is a drought-responsive gene that can increase the drought and salt tolerance of Arabidopsis seedlings overexpressing LpGRP.