Evaluation Of Resistance To TYLCV In Artificial Small RNA Transgenic Tomatoes

Tomatoes are the world’s largest vegetable crop,with not only delicious flesh and excellent taste,but also rich in nutrients.Therefore,they have been loved by people around the world for many years.However,in recent years,tomatoes have been susceptible to TYLCD(Tomato yellow leaf curl disease)transmitted by the tobacco whitefly during production.After being infected,the edges of tomato leaves generally curl and turn yellow,the growth and development speed slows down,and the fruits are small and in small quantities,which seriously affects normal tomato production.TYLCD is caused by the infection of Tomato Yellow Leaf Curl Virus(TYLCV),a single component of the bean golden mosaic virus genus in the Geminiviridae family,including13 TYLCVs recognized by the International Committee on Virus Classification.Due to the continuous infection and recombination of different TYLCVs,which may generate new viruses and cause widespread epidemics,TYLCD has become a major constraint on tomato production in many regions.So,in addition to strengthening field management and scientifically controlling tobacco whitefly,researching new resistant varieties of tomato is currently the most effective method for controlling TYLCV virus.Dr.Anna from our laboratory used Artificial MicroRNA(AMIR)technology to construct a stable transgenic tomato strain.Two techniques,AMIR in introns(AMIN)and AMIR in exon(AMIE),were used to target seven proteins in the TYLCV genome,including C1,C2,C3,C4,V1,CP,and satellite virus b C1.Five different infectious clones of tomato yellow leaf curl virus were also constructed.In this study,five TYLCVs were mixed and infected with Agrobacterium tumefaciens injection or tobacco whitefly infection,respectively.We found that the AMIN and AMIE transgenic lines had significantly better disease resistance than the control group’s wild-type tomato material A57(P < 0.05),and there was no significant difference in yield and quality between the transgenic and A57 fruits without infection(P < 0.05),Under the condition of infection,all quality indicators were significantly higher than A57(P < 0.05).The specific research results are as follows:1.Two tomato resistance identification experiments were conducted to study the resistance of AMIR transgenic tomatoes to various TYLCVs.The first experiment of this study used Agrobacterium tumefaciens injection method and tobacco whitefly method mixed infection to identify and screen transgenic tomato materials with good resistance for the second experiment;The second experiment was conducted to identify the resistance of transgenic tomato materials to TYLCV at different growth stages by infecting them with tobacco whitefly at different growth stages.Prima facie showed that AMIR transgenic tomato could have stable resistance to various TYLCVs.2.The sensory quality and nutritional quality of AMIR transgenic tomato were studied by two groups of tomato fruit quality identification tests.In the first group of experiments,healthy transgenic tomato materials without TYLCV infection were used as the research object,and wild tomato materials were used as the negative control to identify the sensory quality and nutritional quality of their fruits;The second group took the transgenic tomato materials infected with TYLCV as the research object,and the wild type materials as the negative control,and the disease resistant variety TY1 as the positive control to identify the sensory quality and nutritional quality of the above tomato fruits.Through two groups of experiments,it was proved that the fruit quality of transgenic tomato with AMIR technology would not be affected by transgenic technology when it was not infected with TYLCV;After infected with TYLCV,the transgenic tomato fruit with AMIR technology could also better maintain the original sensory quality and nutritional quality.In combination with the ability and quality of TYLCV resistance,the transgenic tomato fruits using AMIR technology and AMIE technology respectively showed strong resistance and good quality.Among them,the transgenic tomato using AMIN technology showed better performance,which can become the focus of breeding excellent resistant varieties in the future.