Functional Analysis of TaMYB1 Gene in Wheat Under Cadmium Stress
[Objective]Members of the MYB family play key roles in diverse biological processes including regulation of plant growth and development,biotic and abiotic stress.However,there were few researches specifically focusing on the function of MYB transcription factors in the response to cadmium(Cd)stress in Triticum aestivum.Therefore,identifying Cd-responsive genes and illustrating their biological function may lay a foundation for wheat Cd-resistant or low-Cd breeding.[Method]Firstly,the yeast cDNA library of wheat roots under Cd stress was constructed,and then the Cd-resistant gene was screened.Then,the expression patterns of Cd-resistant gene in different tissues under Cd stress were examined by quantitative real-time PCR(RT-qPCR).The function of the gene was verified by virus-induced gene silencing,and physiological and biochemical indicators such as the Cd content,chlorophyll content,malondialdehyde(MDA)content,superoxide dismutase(SOD)and peroxidase(POD)activities of the control and gene-silenced plants were detected.Finally,the candidate Cd-resistant gene and its homologous genes in other plants were analyzed by evolutionary relationship,gene structure and expression profile in detail.[Result]The results indicated that root development of wheat was mainly inhibited under Cd stress.Total 18 positive transformants were screened by cDNA library on a tolerance of 0.002 mol/L Cd,and five transformants encoded TaMYB1 protein,which grew well while the control yeast strains restrained in high Cd medium.Results of RT-qPCR indicated that TaMYB1 responded to Cd stress in the wheat.Compared to the control,TaMYB1 expression in TaMYB1-silencing wheat significantly decreased and the concentration of Cd in the roots and leaves as well MDA content were remarkably lower than that in the control plants,while the contents of chlorophyll and the activities of SOD and POD increased apparently in TaMYB1-silencing plants.Meanwhile,bioinformatics analysis found that TaMYB1 belonged to the 1R-MYB family with highly conserved MYB and CC domains,containing seven exons and six introns.TaMYB1 expressed the highest in the inflorescences of two nodes or internodes visible stage and maximum stem length reached stage,while the lowest in in pre-filling seeds and mid-and late-filling seeds.[Conclusion]TaMYB1 plays a important role in wheat response to Cd stress.
万方数据
维普
