Molecular cloning and characterization of OsLRK1 encoding a putative receptor-like protein kinase from Oryza sativa

A cDNA clone, OsLRK1, encoding a leucine-rich repeat receptor-like protein kinase was isolated from the immature panicles of rice. The OsLRK1 protein was composed of a leucine-rich extracellular ligand-binding domain, a membrane-spanning segment, and a cytoplasmic kinase domain. The OsLRK1 protein showed the highest sequence homology with Arabidopsis CLV1. The OsLRK1 transcript was present at a high level in immature panicles and at a low level in seedling shoots, immature seeds, and mature seeds, while no expression was detected in seedling roots and panicles at the heading stage. This expression pattern is similar to that of CLV1, which suggests that the rice clone may play a critical role in meristem development. The function of the rice OsLRK1 gene was studied by the transgenic approach. Antisense expression of OsLRK1 in rice plants resulted in increased numbers of flower organs, suggesting that the OsLRK1 gene is involved in floral meristem activity. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.