Abstract
Cell-to-cell peptide-signaling mechanisms like animal systems have been considered in functioning in diverse ranges of plant development. Recent advances in analyses of CLV3/ESR-related (CLE) peptides have revealed some of their functions in modulating cell proliferation and differentiation, but most of CLE peptide functions remain unknown. Here we applied an Arabidopsis pollen tube culture to examine the effects of 27 synthetic CLE peptides on pollen tube growth. Pollen tubes grew longer in the presence of certain types of CLE peptides. CLE peptide-receptor genes were supposed to be expressed in pollen tubes or pollen grains when the pollen tube growth differently responded to each CLE peptide. We next chose receptor-like kinase genes from those similar to the known CLE receptor genes, based on published gene expression data of pollen. The corresponding T-DNA insertion mutants are now being subjected to the pollen tube culture with the synthetic CLE peptides, which showed the promoting activities on wild type pollen tube growth. This approach would contribute to identify new CLE peptide-insensitive mutants, in which receptor-like kinase genes are impaired.