Relationship of Tolerance to TMV and Glutathione Metabolic Pathway in Tobacco

WANG Jing; ZHOU Qi; LI Lihua; HAO Fengsheng; WEI Yuanfang; YANG Lijun; LIU Weiqun

doi:10.15933/j.cnki.1004-3268.2017.02.010

Abstract：In order to further explore the resistance mechanism of tobacco to tobacco mosaic virus (TMV),two tobacco varieties,NC89 and Yuyan 8 which is tolerant to TMV and has the same genetic background as NC89, were used as materials, and bioinformatics analysis using transcriptome data obtained by high-throughput sequencing found that there was common response to glutathione metabolism after inoculation with TMV in the two varieties,and the response of Yuyan 8 was enhanced. We detected the change of transcription of glutathione S-transferase( GST) gene in glutathione metabolic pathway with quantitative PCR,the enzyme activity of GST and glutathione( GSH) content with spectrophotometry in the two varieties after inoculated by TMV. The results showed that the transcription level of GST gene, the enzyme activity of GST and the GSH content were increased,and the increase rate in Yuyan 8 was higher. The influence of TMV infection on the expression level of GST and other genes related to TMV tolerance was studied by the sulfur concentration experiment. The result showed that whether + S or - S, the expression trend of these genes in the two varieties was same,but the expression level in -S treatment was less than in the +S treatment. The expression of the genes related with disease resistance( GST,PR1-a,HSP90,Catalase-3) was increased after infection by TMV,and the expression level of Yuyan 8 was higher than NC89. The two genes involved in photosynthesis,PsbA and PhotosystemⅡ10 kDa polypeptide showed reduced expression, but the reduced rate in Yuyan 8 was less than NC89. The results above indicated that in the varieties resistant to TMV infection,enhancement of glutathione metabolic pathway was beneficial to cellular redox balance,which stabilized the expression of PsbA that encodes the key D1 protein in photosystem Ⅱ,and decreased the damage degree of TMV to photosynthetic system.