水稻胚胎發育期與種子萌芽期之熱休克蛋白質調節機制探討(3/3)

High temperature (≥35℃) can affect rice seedling development, tillering, plant height, root system growth, grain and quality. To acclimate the hot and humid environment in tropical and subtropical regions, rice has evolved a series of complex molecular mechanisms, such as accumulation of heat shock proteins (HSPs). Previous results have showed that OsHsp16.9A can function together with the key HSP, OsHsp101, in seed thermoresistance, upregulate starch synthesis gene transcripts to affect starch grain arrangement, and increase the expression levels of protein prenylation enzyme genes. Also, we found that light was able to activate OsHsp101 degradation mechanism during rice seed germination. Based on our previous results, we plan to further investigate the mechanism for thermoresistance of rice seeds in this three-year project. Firstly, the topic is to analyze the interplay between OsHsp16.9A and OsAPL3, OsPYK, and OsG6PGH. By using the techniques of Ratiometric bimolecular fluorescence complementation (rBiFC) and GST-pull down, we try to understand that OsHsp16.9A can directly or indirectly affect starch synthesis gene expression. Secondly, the topic is to explore the degradation mechanism for OsHsp101 during rice seed germination. By applying proteasome inhibitors, GST-pull down assay and transcriptome sequencing, we try to identify the protein molecules involved in the proteasome for OsHsp101 degradation. Thirdly, the topic is to elucidate the role of prenylation in the mechanism for thermoresistance of rice seeds. By analyzing prenylation inhibitors and prenylation-related mutants, we plan to confirm that the transition of hydrophilicity to hydrophobicity of the target proteins is an important protein modification in the mechanism for thermotolerance of rice seeds. These results will help us to further understand the resistance mechanism of rice seeds to environmental high temperatures, and improve the problems of rice seeds exposed to high temperatures, such as stunted growth, less tillers, reduced seedling rate and poor rice quality.