High and low temperature injuries to microsporogenesis by decreasing phytohormones, auxin and gibberellin(Science Saloon)

Abstract

Studies on high-temperature injury and cool-weather damage in crops, wheat, barley and rice have a long history, and have identified physiological responses including abnormal abortion of developing pollen followed by male sterility. However, a full understanding of the molecular mechanism has not been achieved. We here show that endogenous auxin levels specifically decreased in the developing anthers of barley and Arabidopsis under high temperature conditions. Similarly, endogenous gibberellin levels significantly reduced in the developing anthers of rice by decreasing temperatures. In addition, the temperature fluctuations repressed each gene expression of auxin biosynthesis genes, YUCCA yuc-2 and yuc-6, and gibberellin biosynthesis genes, GA20ox3 and GA3ox1. These set of genes are dominantly expressed in the developing anthers indicating that at least auxin and gibberellin are synthesized in the anthers. It may lead to susceptibility to male sterility in temperature stress.