Heat stress is important factors that affect plant growth and development and cause crop yield reduction worldwide. Phospholipase C is a key enzyme in the phospholipid signaling system of inositol. It hydrolyses 4, 5-diphosphatidylinositol to produce inositol 1,4,5- trisphosphate (IP3) and diacylglycerol (DAG) have been found involved in stress responses in many plants. In this study, Transgenic Arabidopsis (overexpression) and transgenic wheat (RNA interference) were used as materials to observe the phenotypes under heat stress. Transcriptome sequencing was performed on WT and transgenic wheat under normal and heat stress conditions under normal and heat stress. And the heat-resistant interacting proteins were screened through a yeast library. Based on RNA-seq and screening results of interaction proteins, combined with phenotypic data and cytological observation, it was found that overexpression of TaPI-PLC1-2B decreased the heat resistance of Arabidopsis , while RNAi-TaPI-PLC1-2B enhanced the heat resistance of wheat. RNA-seq results showed that differential genes (DEGs) were mainly enriched in protein processing in the Endoplasmic reticulum, MAPK signaling pathway-plant, and plant-pathogen in wheat seedlings after heat stress. Further mining transcriptome data, we found that RNAi-TaPI-PLC1-2B was related to stomatal changes. Then, we observed stomatal changes in wheat leaves during different periods of heat stress by scanning electron microscopy. The results showed that transgenic wheat closed stomatal earlier than WT, thus making transgenic wheat more heat resistant than WT. It was confirmed that the TaPI-PLC1-2B gene was located in the cell membrane, and then five candidate interacting proteins were obtained through the screening library. The interaction between TaPI-PLC1-2B and TaHsp 90.1-B1(TraesCS2B02G047400) and wheat ribulose bisphosphate carboxylases subunit (TraesCS5D02G169900) in yeast was verified.

In conclusion, after heat stress, TaPI-PLC1-2B gene acts on downstream CaMCML through Ca2+, promoting stomatal closure. Ca2+ also acts on MAPK4 and upregulates WRKY33 in response to heat. TaPI-PLC1-2B and TaHsp 90.1-B1 May interact with each other in the plasma membrane or cytoplasm, leading to cell membrane remodeling after heat stress in response to heat stress, and inhibiting HsFA1 to negatively regulate heat stress.