Exploration And Functional Analysis Of ABA Responding Genes In Guard Cells Of Wheat

The stomate,surrounded by guard cells,is an important valve to control water loss and gas exchange between the plant and the environment.Abscisic acid is an important plant stress hormone,which plays an important role in response to abiotic stress.Under the treatment of ABA,the turgor pressure of the guard cells decreases and the stomate is closed,so as to reduce water loss and maintain the water balance and stable growth and development of the plant.Clarification of the mechanism of abiotic stress and genetic improvement of wheat resistance are of great significance to China’s food security.In view of this,isolation of abscisic acidinduced guard cells from wheat and single-cell transcriptome sequencing were carried out in this study.The main results are as follows.Single cell isolation was carried out on guard cells treated with abscisic acid to obtain high physiological activity guard cells and epidermal cells,which were sequenced by high-throughput transcriptomic platform.The results showed that2533 genes expressed in epidermal cells and 4435 genes were repeat expressed in guard cells,of which 3021 genes were specifically expressed in guard cells.The differentially expressed genes encode elements of ABA,calcium,and jasmonic acid signaling pathways,lipid metabolic proteins,protein kinases,transporters,ion channels,transcription factors,and other stress related proteins.The key candidate genes CIPK25 and WD40 were cloned,and the expression vectors were constructed.The transgenic Arabidopsis plants were obtained by Agrobacteriummediated method.Phenotypic identification results showed that CIPK25 and WD40 transgenic plants had stronger drought resistance than wild type plants Col-0,and the water loss rate of detached leaves was significantly slower than that of Col-0.Under ABA treatment,stomatal aperture of transgenic plants was significantly less than that of wild type,indicating they were hypersensitive to ABA.Similarly,under NaCl treatment,transgenic plants showed significant salt tolerance.In summary,this study established a high-throughput single-cell sequencing method for wheat guard cells,providing a theoretical basis for revealing the molecular mechanism of wheat responses to abiotic stress.