ICE1 plays a vital role in the development of pollen grains through regulating tapetum degradation and nutrient mobilization in Arabidopsis thaliana.

ICE1 (Inducer of CBF Expression 1) of Arabidopsis thaliana is a transcription factor involved in a wide range of physiological processes, including stress responses and plant development. Recently, the regulatory role of ICE1 in the development of the male reproduction system was reported; the failure of the ICE1 mutant ice1-2 to carry out anther dehydration was observed to have resulted from impaired stomata development. In this study, we show that ICE1 influences anther and pollen development by facilitating timely tapetum degradation and nutrient mobilization. Transmission electron microscopy revealed that ice1-2 pollen grains exhibited disorganized cytoplasm and large vacuoles. Semi-thin sectioning of ice1-2 anthers from different developmental stages showed retarded anther dehiscence, defective pollen grains, and delayed tapetum degradation. In addition, ice1-2 exhibited altered sugar and lipid distribution patterns, suggesting that abnormal pollenkitt deposition results from impaired nutrient mobilization and defective tapetal degradation. Lastly, we also investigated and confirmed interactions between ICE1 and key regulators of tapetum and pollen development, DYT1 and AMS. Together, our observations suggest an additional role of ICE1 in anther and pollen development via the regulation of tapetum development, likely through the interactions of ICE1 and other transcription factors involved in tapetal and pollen development.