Study On The Function Of Tabacco Lipid Transfer Protein NtLTP1 Gene

Lipid transfer protein is also known as phospholipids exchange of protein.It is found in large numbers in plants of small molecules that are rich in cysteine alkaline lipid binding protein and can be combined with a variety of hydrophobic molecules reversibly in vitro.Existing research has shown that LTPs can transport a variety of lipid across the membrane,and able to participate in biological and abiotic stress response.We took TI1068 tobacco as the transformed strain,and made a detailed analysis of the basic characteristics of this gene by using bioinformatics related software.We transferred Nt LTP1 into TI1068 tobacco strain through agrobacterium transformation technology,and conducted a preliminary study on the function of this gene.The main findings are as follows:1.Through PCR and q PCR testing of transgenic tobacco,it was found that the expression level of Nt LTP1 gene in transgenic tobacco plants was increased to different degrees,increasing by about 1.44~2.59 times.Through bioinformatics software analysis found that Nt LTP1 genes encoding 114 amino acids.The protein molecular weight was 11.7309 KDa.Theoretical isoelectric point(p I)was 9.02,and the protein has landmark conservative areas of ECM?4 alpha helix(46.49%)and signal peptide.It is a kind of hydrophobic alkaline proteins.2.Wild type and transgenic tobacco seeds by high salt and drought stress treatment,the results show that in the high salt and dehydration conditions,with the increase of concentration,wild type tobacco and germination rate of the transgenic tobacco are lower,but it is still of the transgenic tobacco germination rate is higher than the wild type,and the roots of the transgenic tobacco plants grow higher than the wild type plants.In drought and high salt environment,transgenic tobacco have a greater tolerance to adversity.3.Through the determination of mycelium block resistance to bacterial wilt in the leaves of wild type and transgenic plants,the experimental results showed that under the same time and environment,the plaque area of theleaves of transgenic plants in vitro was smaller and the onset was later.Through the determination of superoxide dismutase(SOD)and catalase(CAT)enzyme activity,it was found that the SOD and CAT enzyme activity of transgenic plants were significantly enhanced.SOD enzyme activity enhanced 0.38~1.16 times and CAT enzyme activity enhanced 0.25~1.05 times.The resistance of transgenic plants to bacterial wilt was significantly enhanced.4.In the experiment of measuring the permeability of plant leaves,it was found that compared with wild-type plants,the permeability of transgenic tobacco leaves decreased.The staining area of transgenic tobacco was smaller after toluidine blue staining.The water loss rate of transgenic tobacco plants decreased by 8.09%~17.75% compared with the wild type.The chlorophyll content of transgenic plants also decreased by 10.49%~20.98%.It indicated that increasing the expression of Nt LTP1 gene would lead to the decrease of permeability of transgenic plants.5.The content of terpene alcohol in leaf from wild type tobacco and transgenic tobacco plants was determined.The results showed that compared with wild type plants,the content of terpene alcohol from transgenic tobacco was significantly increased by about 0.91~1.45 times and the color of extracts was darker than that from wild type tobacco plants.