Salman Sahid, Chandan Roy, Soumitra Paul , Riddhi Datta.

J Exp Bot; 2020 Aug 27; eraa 400.  doi: 10.1093/jxb/eraa400.

Abstract

Lectin proteins play an important role in biotic and abiotic stress responses in plants. Although the rice lectin protein, Osr40c1, has been reported to be regulated by drought stress, the mechanism of its drought tolerance activity has not been studied so far. In this study, it has been depicted that expression of Osr40c1 gene correlates with the drought tolerance potential of various rice cultivars. Transgenic rice plants overexpressing Osr40c1 were significantly more tolerant to drought stress over the wild-type plants. Furthermore, ectopic expression of the Osr40c1 gene in tobacco yielded a similar result. Interestingly, the protein displayed a nucleo-cytoplasmic localization and was found to interact with a number of drought-responsive proteins like OsSAM2, OsSAP8, OsMNB1B, and OsH4. Silencing of each of these protein partners led to drought sensitivity in the otherwise tolerant Osr40c1 expressing transgenic tobacco lines indicating that these partners were crucial for the Osr40c1-mediated drought tolerance in planta. Moreover, the association of Osr40c1 with these partners occurred specifically under drought stress forming a multi-protein complex. Together, the present investigation delineated the novel role of Osr40c1 protein in imparting drought tolerance by regulating OsMNB1B, OsSAM2, and OsH4 proteins, which presumably enables OsSAP8 to induce downstream gene expression.

See: https://pubmed.ncbi.nlm.nih.gov/32853345/