A novel pistil–pollen interaction via CLE peptide signaling

CLE45 peptide gene is expressed in the transmitting tract along which pollen tubes penetrate under a high temperature condition (upper panel), while pollen express the receptor gene (lower panel). A severe reduction in seed production under the high temperature condition was observed in plants defective in either the CLE peptide gene or the receptor gene function. CLE45 signaling alleviated mitochondrial decay in pollen tubes. This novel CLE-mediated pistil–pollen interaction may adapt plants to diurnal or seasonal temperature fluctuations in their natural habitat.