The leucine-rich repeat receptor-like kinase OsERL plays a critical role in anther lobe formation in rice

Abstract

In Arabidopsis, ERECTA (ER) subfamily of leucine-rich repeat (LRR) receptor kinases (LRR-RKs) play important roles in cell division and cell elongation. However, the functions of OsER genes in rice are still very much unknown. In this study, sixty-seven TILLING and four gene-edited mutants were identified for one of the three OsERs, OsERL, and used for functional analyses. Results showed that mutations in OsERL led to striking defects in anther development. Compete male sterility and reduced numbers of anther lobes, more severe than knockout mutants, were observed in mutants with amino acid substitutions in the kinase domain. Among alleles with amino acid changes in LRRs, only one mutation in the 16th LRR showed evident phenotype, suggesting a role of the LRR in ligand sensing. OsERL is expressed in shoot apcies, internodes and anthers, and within the anther OsERL is expressed in sporophytic and tapetal cells. Cell biological analyses revealed that mutations in OsERL led to defected periclinal division in archesporial cells in anthers, suggesting a critical role of OsERL in rice anther development.