The Effect Of Different Ty-genes On TYLCV DNA Accumulation,Transcription And Translocation,and Transcriptomics Of Tomato Plant Response To TYLCV

Tomato Yellow Leaf Curl Virus Disease is a major constraint on tomato production. The resistant genes originating from wild tomato species is a good resoure to control Tomato Yellow Leaf Curl Virus(TYLCV). In order to identify the resistance mechanisms of Ty-genes to TYLCV, two aspects was investigated:(1) The tomato materials carrying Ty-2, Ty-1/Ty-3, Ty-1/Ty-3a, Ty-4 and ty-5, was agroinoculated with an infectious TYLCV-IL[CN:SH2], respectively. And real-time PCR and RT-PCR were used to investigate the effect of different Ty-genes on TYLCV DNA accumulation, transcription and translocation.(2) To understand resistance to TYLCV, the transcriptome analysis of resistant(R) and susceptible(S) tomato lines was performed upon TYLCV-challenge via agroinoculation at 28 days. The main results are as follows:1. The inhibition of Ty-2 on TYLCV accumulation was severe and stable, and was not affected by seasons. Ty-1/Ty-3 acted certain inhibitory effect but was weaker than Ty-2. The inhibition of Ty-1/Ty-3a and ty-5 on TYLCV accumulation was influenced by seasons strongly. The inhibition was strong in spring, but limited in autumn. Ty-4 had weak inhibition on TYLCV accumulation in spring, and had hardly inhibition in autumn.2. The inhibition of Ty-2 on TYLCV transcription was best and unaffected by season. Ty-1/Ty-3 acted certain inhibitory effect in spring, but the inhibition was decreased in autumn, especially on V1 expression. But Ty-1/Ty-3a and ty-5 acted better. They inhibited sharply the transcription of TYLCV in spring, but the inhibition was reduced, especially the inhibition of Ty-1/Ty-3a on expression of V1 and C1 was decreased significantly. Ty-4 had weak inhibition on TYLCV transcription.3. The inhibition of Ty-2 on TYLCV translocation was severe and stable. Ty-1/Ty-3, Ty-1/Ty-3a and ty-5 could not inhibit TYLCV translocation compeletly. But TYLCV in these lines moved to upper leaves later and the accumulation of TYLCV was restricted. Ty-4 had hardly inhibition on TYLCV translocation.4. At 28 days after inoculation, the Ty-4 lines developed symptoms in autumn, while tomato lines carrying Ty-2, ty-5, Ty-1/Ty-3a and Ty-1/Ty-3 remained symptomless.5. Base on the result of the transcriptome analysis, 461 expression genes were different between R and S plant. 5 different expression genes were involved in the photosynthesis pathways. The region where Ty-1/Ty-3 mapped contains three genes. Compared to the S plant, the transcription level of Solyc06g051170 was significantly higher in the R plant. The other two expression genes had no significantly difference.