Auxin depletion in barley plants under high-temperature conditions represses DNA proliferation in organelles and nuclei via transcriptional alterations.

Many plant species are susceptible to high-temperature (HT) injury during reproductive development. We recently demonstrated that HT represses the expression of YUCCA auxin biosynthesis genes and reduces endogenous auxin in the developing anthers of barley and Arabidopsis. Here, we show that DNA proliferation in mitochondria, chloroplasts and nuclei of developing panicles is inhibited with increasing temperatures in barley.

Auxins reverse plant male sterility caused by high temperatures.

With global warming, plant high temperature injury is becoming an increasingly serious problem. In wheat, barley, and various other commercially important crops, the early phase of anther development is especially susceptible to high temperatures. Activation of auxin biosynthesis with increased temperatures has been reported in certain plant tissues.

Premature progression of anther early developmental programs accompanied by comprehensive alterations in transcription during high-temperature injury in barley plants.

High-temperature stress causes abortive male reproductive development in many plant species. Here, we report a putative mechanism of high-temperature injury during anther early development in barley plants (Hordeum vulgare L). Under high-temperature conditions (30 degrees C day/25 degrees C night), cell-proliferation arrest, increased vacuolization, over-development of chloroplasts, and certain abnormalities of the mitochondria, nuclear membrane, and rough endoplasmic reticulum (RER) were observed in developing anther cells, but not in developing ovule cells.