Anti-cold Effect Of Soybean Fatty Acid FAD3 Transgenic Rice And The Effect Of Soybean Le4 Protein On Aphids

Rice is very susceptible to low temperature and pests and other effects of reduced production,improve rice resistance to low temperature and insect resistance,has always been a lot spot in rice research.The increase of unsaturated fatty acid content could enhance the effect of plant on low temperature stress.Leguminosin lectins have unique physiological functions such as agglutinating cells,precipitated polysaccharides and proteins,and have received extensive attention in crop insect resistance.In this study,soybean FAD3 rice with improved content of unsaturated fatty acids was obtained in this study.The differences of FAD3 transgenic plants and wild type plants under low temperature stress were compared by phenotypic analysis,cold physiological and biochemical indexes and gene expression analysis.At the same time,the leptin lectin Le4 protein was obtained by using prokaryotic expression and protein purification technology,and the insecticidal effect of Le4 protein was analyzed.The main results are as follows:1.Analysis of the cold resistance of soybean FAD3 transgenic rice1)GmFAD3 transgenic pure and strain(No.Trans LPZ)was obtained by PCR with hyaluronide screening.The germination rate of seeds in Trans LPZ and wild type plants was observed and statistically analyzed at 15 ?.The results showed that the low temperature germination rate of Trans LPZ seeds was 7 times higher than that of wild type.Furthermore,the Trans LPZ phenotype was observed at low temperature.It was found that the wilting phenomenon of wild-type rice was significantly higher than that of Trans LPZ.After 7 days at room temperature,Trans LPZ transgenic rice seedlings recovered most of them.It was far higher than the wild type control,about4.3 times the wild type.2)The physiological and biochemical indexes of Trans LPZ and wild-type rice under different low temperature conditions were tested.The results showed that the MDA content in Trans LPZ plants was lower than that in wild type at 10 ?,and the lowest can reach about 75.5%,the PRO content in Trans LPZ plants was higher han that of wild-type rice,the highest can reach about 1.31 times,the activity of SOD,POD and CAT in Trans LPZ plants was also higher than that of wild-type rice,thehighest was 3.33 times,2.38 times and 1.61 times higher than that of wild-type rice respectively.The content of MDA in Trans LPZ plants was lower than that of wild type at the low temperature stress of 4 ?,and the lowest was about 88.1% of wild type.The content of proline in Trans LPZ plants was significantly higher than that in wild type,and the highest was about 1.56 times of wild type The activity of SOD,POD and CAT in Trans LPZ plants was also higher than that of wild type rice,the highest was 2.95 times,1.95 times and 2.4 times.2.Analysis of Insect Resistance of Legume Lectin Le4 Protein1)The constructed pET28a-Le4 plasmid was expressed in prokaryotic cells and induced by IPTG inducer.Through the optimization of the induction conditions such as induction temperature,induction time and inducer concentration,it was found that the Le4 protein was obtained in the supernatant at 20 ? for 20 h,and some Le4 protein was purified from the supernatant by nickel column.2)The purified Le4 supernatant and the control group were evenly applied to the wheat leaves by the smear method.The results showed that the growth of the aphids on the leaves coated with Le4 protein was significantly lower than that of the control group Group of 3.6.