Rnai And GroEL Mediated Resistance To Tomato Yellow Leaf Curl Virus(TYLCV)

Tomato yellow leaf curl virus （TYLCV），which is transmitted by the tobacco whitefly,belongs to begomovirus Genera of Geminiviridae. TYLCV is one of the most devastatingviral diseases of many crops worldwide, causing severe economic losses in many crops,including tobacco and tomato. In practice, physical, chemical and biological methods wereapplied to reduce the loss. But the disadvantages exist, such as high cost, not ideal controleffect, even a negative impact on the environment. Thus, one of the most effectivepathways was to cultivate disease resistant lines. In this study, the plant expression vector（SUC₂-GroEL and pBI121-AC1-AC₂） was co-transform by agrobacterium-mediatedtransformation. Identification for disease-resistance of transgenic tomato plants to obtainthe tomato lines with high resistance to the TYLCV. The results are as follows:1. By observing the growth status of tomato explants in differentiation mediumcontaining different concentration of kanamycin, the screening concentration of kanamycinadopted in this study was determined as100mg/L.2. Co-transformation of tomato was conducted with SUC₂-GroEL plant expressionvector （constructed with Arabidopsis thaliana phloem promoter SUC₂and GroEL ofBemisia tabaci） and pBI121-AC1-AC2plant expression vector （constructed with AC1andAC2of TYLCV） by using Agrobacterium-mediated genetic transformation method. Atotal of19regenerated resistant plants were obtained by Kanamycin selection.3. After PCR detection,8positive plants harboring SUC₂-GroEL vector, six harboringpBI121-AC1-AC2vector and3harboring dual vectors were obtained preliminarily.4. After RT-PCR detection,5positive plants harboring SUC₂-GroEL vector,3harboring pBI121-AC1-AC2vector and2harboring dual vectors were obtained, indicatingthat the target gene was successfully expressed at the transcriptional level in tomato.5. Agrobacterium injection inoculation and Bemisia tabaci transmission wereconducted on T₀generation positive plants harboring single/dual gene. After virusdetection and disease-resistance identification,3TYLCV-resistant plants harboringSUC₂-GroEL vector,3harboring pBI121-AC1-AC2vector and2harboring dual vectorswere obtained.6. According to PCR identification, T₁generation positive plants harboringsingle/dual gene were selected for Agrobacterium injection inoculation and Bemisia tabacitransmission experiments. Statistical data of the incidence show that the disease resistance of these transgenic plants has genetic stability. In addition, plants harboring dual geneshave stronger disease resistance than plants harboring single gene.