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Leifsonia xyli subsp. cynodontis (LXC, formerly Clavibacter xyli subsp.cynodontis,) is a widely parasitic Gramineae phloem vascular bundles within the symbiotic bacteria in the early 1980s for the first time be separated from the Bermuda grass (Cyhodon dactylon L.) , identification, research found its symbiotic host, including rice, corn, sugar cane, oats, turf grass, host plants do not lead to illness, available plant leaching liquid culture or with specific primers from plant tissue directly amplified the the Lxc DNA methods to prove its endogenous. By transgenic technology plant exogenous gene expression characteristics of biotechnology in plant breeding, but it faces complex and application security difficulties, some researchers have attempted to take advantage of symbiotic microbes as a foreign gene expression body, microbial platform for gene manipulation, the target gene function in plant genetic composition does not change, this will be a new transgenic approach. Snowdrop lectin (Galanthus nivalis agglutinin, GNA) from the Amaryllidaceae snowdrop lectin, aphids, planthoppers, leafhoppers and other sucking pests and nematodes have a strong toxicity, such as chewing on Lepidoptera The-Pest moderately toxic. This study first in Lxc inoculation rice, the LXC rice symbiotic properties, symbiotic rice growth and development and yield of the study, and then constructed the insecticidal the endophyte Lxc/GNA12-GUS and vaccination rice research by GNA Lxc in rice expression of, get some useful preliminary results: 1. Seedling leaf-cutting vaccination, LXC be able to the students in the rice plants. The Lxc rice growth and yield have a negative impact and promote heading the Mianhui 725, increase in plant height effect, the United States jasmine sticky stimulation effect. 2. Soaking with Lxc broth processing can be achieved for vaccination purposes. Broth soaking germination rate, seedling rate was not obvious, 725 seedling rate Mianhui promoting effect. 5.0OD 650 of bacterial concentration is effective. 3. PCR detection of the vaccination Lxc rice plants were found in various parts of the stems and leaves Lxc symbiosis, but the mature panicle and grain detection signal. Vaccination Lxc-GUS using fluorescence detection to repeat PCR results, exogenous GUS gene expression in rice plants. 4. Construction of the vector containing the the GNA gene of snowdrop lectin, vectors transferred LXC, obtain the insecticidal endophytes LXC / GNA, the inoculated rice in the rice tissue to detect the GAN gene. 5. Lxc / GNA inoculated rice rice brown planthopper resistance sojourn in a number of preliminary identification, found that the rice brown planthopper resistance ability, the sojourn reduce the number of plants brown planthopper. 6. Inoculation LXC / GNA rice soluble sugar content increased significantly. United States jasmine sticky Mianhui, 725 vaccination LXC / GNA Rice, soluble protein content did not change significantly, a significant reduction of early indica D68. The use of acid hydrolysis was measured three inoculation LXC / GNA rice for the tested varieties seedling amino acid content, total amino acids in the stem and leaves of the early indica D68 varieties were lower than the control, up to a significant level; Mianhui 725 varieties stem and leaves total amino acids are higher than that of the control, the difference was not significant: jasmine sticky varieties stem total amino acids higher than that of the control, the difference was not significant, leaf amino acid content lower than that of the control, the difference was very significant level. This study suggests that rice yield after three years of investigation and study, LXC some of the features of the improved rice as exogenous gene carrier to basic feasible on the LXC / GNA vaccination rice brown planthopper resistance identification that brown planthopper resistance ability, but the identification of resistance research worthwhile to continue in-depth. This study shows that to LXC receptor expression vector as a foreign gene expression in plants, the plants get the same or similar function of the target gene without altering its genetic composition, may overcome the kind of genetically modified food crops, safety and technical issues new ways.
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