The Role Of Legume Lectin Gene Le4 In Rice Resistance To Aphids

Rice is one of the most important human food crops,while we loss more than a few billion because of pests every year.Aphids greatly impact on the production of rice in China.After 70 years,aphid has become important rice pests.Plant lectin is the largest lectin family ever found,where legume lectin is the most abundant plant lectin and the most studied lectin.Plant lectins can inhibitory activity of many kinds of insects,including Coleoptera,Homoptera,Diptera and Lepidoptera.Legume lectins have been shown to have insecticidal activity,another study also proved legume lectin transgenic plants retained its insect resistance.In previous work,we screened domestication-related genes in different ways.Then we find encoding legume lectin-related genes in different ways.In this work,the entire sequences of the corresponding gene was gotten using RACE(rapid amplification of cDNA ends)technique,and was renamed Le4(GenBank:FJ997345.1).This research aimed at transgenic rice with Le4 gene encoding soybean lectin,whose resistance and output may be meliorated.Results are as follows:1.We extracted soybean leaves RNA,cDNA fragments was obtained by RT-PCR technique and sequenced,blast results showed Le4 was obtained.2.Expression vector has constructed successfully by the method of double digestion.The result of western blot proved that transgenic BL21can express legume lectin protein.The prokaryotic expression bacteria which overexpression Le4 impact growth and reproduction of aphids were identified preliminarily:pET28a-Le4 transformants protein inhibited the growth and reproduction of aphids.3.The preliminary exploration of the culture method wheat aphid prove:aphids eat fresh wheat or rice seedlings for food,its culture conditions were 22℃,16:8(L:D),humidity of 40%.4.Agrobacterium-mediated transformation method was used to obtain Le4 transgenic plants.And we got 50 lines of Le4 transgenic rice plants.Extract the RNA of several Le4 transgenic plants.RT-PCR results showed that there are four lines that express the Le4.