Differences Of Physiological And Biochemical Reaction Induced By Exogenous Substance Between Resistance/Susceptible To Bacterial Wilt In Tobacco Varieties

Tobacco bacterial wilt was a systemic infectious disease caused by Ralstonia solanacearum, and now it has become one of the main diseases in the world of tobacco-planting area. It is one of main diseases in South China of tobacco area.Once the tobacco plants are infected with tobacco bacterial wilt, the whole would die.So it has major impact on the yield and quality of tobacco and a destructive disease to tobacco. At present, the control measures of tobacco bacterial wilt such as rotations,resistant breeding, chemical and biological control had no obvious effect. As we know,the induced disease resistance of plant is one of measures to effectively using resistance resources itself, which had the advantages of multiple resistance, high resistance and security in plant. In order to adapt to abiotic and biotic stress, plants produce secondary metabolism materials, which is important in plant growing development, resistance, stress and so on. Thus, it is useful to study the defensive enzyme activities and metabolism of resistance to disease.Resistant(Yue-yan 97) and susceptible(Chang-bohuang) tobacco cultivars were treated with Ralstonia solanacearum, BTH, and Lansiumamide B at 3-leaf stage. The affect and dynamic change of these treatments to tobacco were studied by using photosynthetic system, colorimetric method and GC-MS respectively, including photosynthetic characteristics, four defensive enzyme activities and metabolites. The results were shown as following:1. The treatments significantly inhibited photosynthesis and transpiration compared to control in tobacco cultivars of Yue-yan 97, while enhanced in tobacco cultivars of Chang-bohuang.2. After treatments: in Yue-yan 97 PAL, SOD and POD activities increased compared to control in the earlier days, and PPO activity was increased compared to control in the later days, while in Chang-bohuang PAL, SOD, PPO and POD activities increased compared to control in the later days after treated with chemical inducers(BTH and Lansiumamide B), and the activities was increased compared to control in the earlier days after treated with Ralstonia solanacearum. For both cultivars, PAL, SOD, POD,and PPO activities increased compared to control in the earlier days, but were lower compared to control during the later time period after inoculation.3. After treatments: in Yue-yan 97 the number, width and color of isozymes bands were induced or enhanced, and they were gradually weakened with time flow in treatment group of Ralstonia solanacearum; in Chang-bohuang they were not enhanced in treatment group of Ralstonia solanacearum, and enhanced in treatment group of chemical inducers(BTH and Lansiumamide B).4. The PAL, SOD and POD activities and types of isozymes POD and PPO in the resistant cultivar Yue-yan 97 were higher than those in the susceptible cultivar Chang-bohuang. Therefore, in Yue-yan 97 the activity of defensive enzymes were increased rapidly after treated by inoculation or elicitors, and produced a large number of disease resistance related substances for inhibiting bacterial wilt, in Chang-bohuang were relatively weak.5. After treatments: in Yue-yan 97 detection of metabolites showed that the relative percentage contents of some defense-related substances reflecting the ability of resistance to bacterial wilt such as lactic acid, nicotine, malonic acid, malic acid,L-threonic acid, D-lyxose, ribitol, tetradecanol, L-arabinose, ribose acid, shikimic acid,tartaric acid, citric acid, D-Arabinitol, palmitic acid, D-galactose, glucopyranose, myo inositol, octadecanoic acid, D-mannitol, L-tyrosine, D-fructose(anti), D-erythritol,pentanoic acid, L-glutamate, L-asparagine were all increased or reduced compared to control, and the differences in metabolic markers were boric acid,7-Ethyl-2-methyl-4-undecanol, L-threonic acid, D-rhamnose, n-hexadecane,erythronic acid, D-Cellobiose, ribonucleic acid, malonic acid, shikimic acid, citric acid; in Chang-bohuang the substances such as L- isoleucine, malonic acid, malic acid, erythritol, 7-Ethyl-2-methyl-4-undecanol, glycerol, butanedioic acid,D-erythrosel, scyllo inositol, myo inositol, hexadecanoic acid, octadecanoic acid,D-fructose, D-glycero-D-gulo-heptose, D-cellobiose were all increased or reduced compared to control, and the differences in metabolic markers were boric acid,acetylformic acid, n-nonanoic acid, L-arabitol, L-glutamic acid, diethylene glycol,L-2-piperidine carboxylic acid, n-hexadecane, heptadecane,2,6,10,14-tetramethyl-pentadecane, L- arabinose, malic acid, L-threonic acid,dodecanol and ribose acid.