Analysis Of The Regulation Effect Of SlNAC1 Transcription Factor On The Genes Related To Betaine Synthesis

Transcription factor is an important regulator of the function of regulating gene expression.NAC is a plant-specific transcription factor involved in plant biotic and abiotic stress responses.The SNAC1 gene of Suaeda liaotungensis was cloned in the early stage of the laboratory.SlNAC1 increased the resistance of transgenic Arabidopsis thaliana.Betaine is a non-toxic small molecule osmotic regulator that plays an important role in improving plant stress resistance.Phosphoethanolamine nitrogen methyltransferase(PEAMT),choline monooxygenase(CMO),and betaine aldehyde dehydrogenase(BADH)are key enzymes for the synthesis of betaine.The SIlPEAMT,SlCMO,SlBADH genes and their promoters were cloned in the early stage of the laboratory,and the promoter sequence contained the NAC transcription factor binding site(CGTG/A).This paper intends to study the regulatory relationship between the transcriptional factor of SlNAC1 and the expression of genes related to betaine synthesis.Quantitative Real-time PCR was used to analyze the expression of SINACl and SIPEAMT,SlCMO and SIBADH in Suaeda liaotungensis,and the betaine content was determined.Yeast one-hybrid assay was used to analyze the interaction of SlNAC1 transcription factor with the SlPEAMT,SICMO and SIBADH promoters.The main results and conclusions are as follows:Under the condition of abiotic stress,the expression levels of SlNACl,SIPEAMT,SICMO and SIBADH genes in Suaeda liaotungensis were significantly increased.Under low temperature conditions,the expression levels of SlNAC1,SIPEAMT,SlCMO and SIBADH were peak at 0.5h,12h,24h and 24h,respectively,and the betaine content peaked at 24h.Under salt conditions,the expression levels of SlNACl,SIPEAMT,SICMO and SIBADH were peak at 6h,24h,12h and 24h,respectively,and the betaine content peaked at 24h.Under the condition of 10%PEG,the expression levels of SlNAC1,SIPEAMT,SICMO and SIBADH were peak at 6h,12h,12h and 12h,respectively,and the betaine content peaked at 12h.Under ABA conditions,the expression levels of SlNACl,SlPEAMT,SlCMO and SIBADH were peak at 3h,12h,12h and 12h,respectively,and the betaine content peaked at 12h.The results showed that the expressions of SlNAC1,SIPEAMT,SICMO and SIBADH genes were induced by low temperature,salt,drought and ABA,and the expression of SINACI gene was earlier than that of SlPEAMT,SlCMO and SIBADH genes,suggesting that SIPEAMT,SICMO and SIBADH genes may be expressed.The downstream gene of the SlNAC1 transcription factor is regulated by it,and the corresponding betaine content is increased.The results of yeast one-hybrid assay showed that SlNACl transcription factor could interact with SlPEAMT,SICMO and SIBADH promoters,suggesting that SlNAC1 may directly regulate the expression of SIPEAMT,SICMO and SIBADH genes.In summary,the SIPEAMT,SICMO and SIBADH genes may be direct targets of the SlNAC1 transcription factor.SlNAC1 directly regulates the expression of SIPEAMT,SICMO,and SIBADH,thereby regulating the synthesis of betaine and improving plant stress tolerance.This study provides a theoretical basis for the study of the mechanism of SlNAC1 transcription factors to enhance plant stress resistance.