Characteristics Of Carbohydrate Metabolism And Betaine Metabolism Of A Genic Male Sterility Wheat Line BNS During Anther Development

Pollen fertility of photoperiod-sensitive and temperature-sensitive genic male-sterile wheat is= controlled by genetic genes,and gene expression is regulated by non-biological conditions.At certain developmental stages,changes in light or temperature led to changes in pollen fertility.The leaf was the main organ that felt the environmental stress,but it finally affected the development of anthers.However,in the study of plant male sterility,the relationship between vegetative organs and anthers has not been paid enough attention,and the physiological and metabolic changes of anthers after stress have not been comprehensively and systematically studied.On the basis of cytological observation,~1H NMR spectrum was used to detect and analyze the metabolites,physiological metabolic changes and main differential metabolic pathways in the anthers,leaves and stems of BNS wheat at different development stages,and the genes related to carbohydrate metabolism and betaine metabolism in the anthers were cloned and analyzed by combining molecular biology methods.The results showed that 53,42 and 41 metabolites were detected in the anthers,leaves and stems,respectively.Almost all of the differential metabolites detected in the anthers,leaves and stems at different development stages included sucrose,glucose,fructose,malic acid and betaine.Moreover,the main differential metabolites among the anthers,leaves and stems of different fertile wheat also included the above five metabolites,indicating the importance of the above metabolites in the metabolism of source and sink organs,and the possible correlation between different organs in the metabolism of the above metabolites.In addition,the above metabolites were likely to be involved in the development of anthers and the formation of fertility.Carbohydrate metabolism plays a vital role in plant male reproduction.In this study,c DNA sequences of 11 genes related to carbohydrate metabolism pathways were cloned and analyzed,and the sequence consistency of each gene with that reported in wheat was greater than 95%.The results of tissue-specific expression showed that all the above genes were expressed in the anthers.The results of differential gene expression showed that the expressions of Ta6SFT and Ta6FEH were very sensitive to low temperature,and the expression change was the most significant after low temperature stress,which led to sucrose accumulation and abnormal expression of Ta SUS1.Subsequently,there were significant changes in genes related to carbohydrate metabolism.In particular,the expression of Ta SUT1 and Ta IVR1 were significantly inhibited in the LM stage,resulting in significantly reduced carbohydrate transport,thus affecting the synthesis of pollen starch grains.These results indicated that the abnormal changes of fructan metabolism during low temperature stress were likely to be the key events leading to male fertility transformation.It might not only affect the resistance of anthers to stress,but also affect the internal change pattern of fructan as an anther storage polysaccharide,and finally affect the physiological metabolism and development of anthers.In this study,the DNA and c DNA sequences of 5 genes related to choline and betaine synthesis were cloned and analyzed by bioinformatics.The Ta CMO gene was first cloned in wheat,and its encoded protein sequence was 94.89%consistent with the reported barley CMO protein sequence,possessing a plant monooxygenase conservative domain and[2Fe-2S]domain.The results of evolutionary tree showed that the genetic relationship of wheat CMO protein and barley CMO protein was the closest.The above genes were all expressed in the anthers,indicating that there were choline and betaine metabolic pathways in the anthers.Choline in the anthers is directly generated mainly through the hydrolysis of phosphatidylcholine,and there may be a choline acetylation pathway.The changes in gene expression of Ta PEAMT1,Ta CMO and Ta BADH1were consistent with those in choline and betaine contents,indicating that the above three genes played primary roles in the synthesis of choline and betaine.Subcellular localization showed that Ta CMO was expressed in the nucleus and cytoplasm,and Ta BADH1 and Ta BADH2 were both expressed in the cytoplasm and cell membrane,indicating that betaine was likely synthesized in the cytoplasm.Betaine was accumulated in a large amount in the pollen when the anthers mature,and its effect needs further investigation.