Heat stress induces spikelet sterility in rice at anthesis through inhibition of pollen tube elongation interfering with auxin homeostasis in pollinated pistils

Pollen tube elongation in the pistil is a key step for pollination success in plants, and auxins play an important role in this process. However, the function of auxins in pollen tube elongation in the pistil of rice under heat stress has seldom been previously reported. Two rice genotypes differing in heat tolerance were subjected to heat stress of 40 °C for 2 h after flowering. A sharp decrease in spikelet fertility was found in the Nipponbare...