Analysis Of The Insect-resistant Function For Ribosome Inactivation Protein From Camellia Sinensis

In the world, the economic loss of crops caused by insect pests was about around several hundred billion dollars per year. Chemical is a primary mean of pest control. It is obviously easy to operate, but the problem of environmental pollution caused by drug residue is increasingly serious. With the rapid development of genetic engineering and molecular biology, it has great significance to high yield, good quality, and insect-resistant crop variety.We isolated the cDNA of a Ⅱ type ribosome inactivation protein gene from tea variety, Fuzao2, by RACE method, which is designated as CsRIPI. The expression of CsRIPI was induced by green leafhopper. Ribosome inactivation proteins (RIPs) are N-glycosidases that can damage ribosomes in an irreversible manner, and therefore, inhibited protein synthesis. RIPs might be involved in antiviral activit, and increase protection against fungal pathogen and insect damage. This protein such widespread in plants, the unique cytotoxicity of RIPs will proude a possible way in the breeding of crop with increased insect-resistance.Tobacco is of the most China’s important economic plants, but there are a variety of tobacco plant diseases and insect pests, which is difficult to control. In this study, the pBI121-CsRIPI plasmid was constructed, and transgenic tobacco plants which expressed CsRIPI gene were obtained by Agrobacterium-mediated transformation. Resistance evaluation of TO transgenic tobacco to peach aphid and black cutworm was carried out by indoor leaf inoculation method. The result showed that the survival rate and the reproduction capacity of peach aphid fed with leaves from transgenic plants were lower than control, demonstrating transgenic tobacco harboring CsRIP I had significant effect on the fecundity of aphid. The mortalily of newly hatched larva fed with transgenic tobacco was higher than those fed with wild tobacco.Transgenic tobacco had low effect on mortality of1st intar and2nd instar larvae. Howere, had no effect on mortality of3st intar larvae.