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以菜心品种为材料,设置不同浓度对羟基苯甲酸(pHBA)处理,并通过人工接种炭疽病菌,研究pHBA对菜心炭疽病的诱导抗性作用机理。结果表明,在菜心生长发育过程中根系可以分泌出pHBA。pHBA对菜心的生长、产量形成和炭疽病的发生有明显的影响。适宜浓度的pHBA处理可促进菜心生长,提高植株对炭疽病的抗性,显著地降低病情指数(DI),提高菜薹产量,但当pHBA积累到一定浓度时,就对菜心植株产生自毒作用,提高DI和降低菜薹产量。炭疽病菌的感染破坏了植株细胞膜,增强细胞膜透性水平,诱导产生病程相关蛋白(几丁质酶、β-1,3-葡聚糖酶)和细胞壁物质(木质素、富含羟脯氨酸糖蛋白(HRGP))。适宜浓度的pHBA处理可抑制炭疽病菌对细胞膜透性的伤害,加强诱导提高几丁质酶活性、β-1,3-葡聚糖酶活性、木质素含量和HRGP含量,引起细胞壁木质化加强,增加了菜心植株对炭疽病的诱导抗病能力,从而阻止病原菌进一步侵入和扩散,抑制炭疽病菌对菜心产量造成的损失。
Taking Brassica campestris var. As a material, different concentrations of p-hydroxybenzoic acid (pHBA) were set up and anthracnose was inoculated by artificial inoculation to study the mechanism of inducing resistance of Brassica campestris by pHBA. The results showed that the root system can secrete pHBA during the growth and development of Brassica campestris. pHBA had significant effects on the growth of Brassica campestris, yield formation and occurrence of anthracnose. Appropriate concentration of pHBA could promote the growth of Brassica campestris, increase the resistance of plants to anthracnose, significantly reduce disease index (DI) and increase the yield of cauliflower, but when pHBA accumulated to a certain concentration, Toxic effects, improve DI and reduce the production of vegetable stalks. Infection with anthrax bacteria destroys plant cell membranes, enhances membrane permeability and induces the production of disease-associated proteins (chitinase, β-1,3-glucanase) and cell wall substances (lignin, hydroxyproline Glycoprotein (HRGP)). Appropriate concentrations of pHBA could inhibit the injury of cell membrane permeability by anthracnose and enhance the activity of chitinase, β-1,3-glucanase, lignin content and HRGP content, and increase the lignification of cell wall, Increased Brassica campestris plants induced disease resistance to anthracnose, thereby preventing further invasion and spread of pathogens, inhibiting anthracnose bacteria on the yield of cabbage production losses.