He X, Li L, Xu H, Xi J, Cao X, Xu H, Rong S, Dong Y, Wang C, Chen R, Xu J, Gao X, Xu Z.

Plant Biol (Stuttg). 2016 Oct 8. doi: 10.1111/plb.12514. [Epub ahead of print]

Abstract

Abiotic stresses have a significant impact on plant productivity and crop quality. Although plant lectins are thought to play important roles in plant defense signaling during pathogen attack, little is known about the contribution of plant lectins to stress resistance. We cloned and functionally characterized a rice jacalin-related mannose-binding lectin gene, OsJRL, from rice 'Nipponbare'. The cDNA of OsJRL contained a 438 bp open reading frame, which encodes a polypeptide of 145 amino acids. OsJRL was localized in the nucleus and cytoplasm. Real time PCR analyses revealed that OsJRL expression showed tissue specificity in rice and was upregulated under diverse stresses, namely salt, drought, cold, heat and abscisic acid treatments. Overexpression of OsJRL in E. coli enhanced cell viability and dramatically improved tolerance of high salinity. Overexpression of OsJRL in rice also enhanced salinity tolerance and increased the expression levels of a number of stress-related genes, including three LEA (late embryogenesis abundant proteins) genes (OsLEA19a, OsLEA23 and OsLEA24), three Na⁺ transporter genes (OsHKT1;3, OsHKT1;4 and OsHKT1;5) and two DREB genes (OsDREB1A and OsDREB2B). Based on these results, we suggest that OsJRL plays an important role in cell protection and stress signal transduction.