外源5-氨基乙酰丙酸激活叶绿素合成诱导菊花抗白粉病研究

Activation of Chlorophyll Synthesis by Exogenous 5-Aminolevulinic Acid Induces Powdery Mildew Resistance in Chrysanthemum morifolium

以切花菊品种神马为试验材料,设置外源5-氨基乙酰丙酸(ALA)预处理再接种白粉病菌(A1)、施用ALA和接种白粉病菌同时进行(A2)这2种处理方式(ALA浓度为0、0.1、1、10、25、100 mg/L),探究外源5-氨基乙酰丙酸对白粉菌的抗病效果以及抗病途径。结果表明:与0 mg/L处理相比,喷施适宜浓度的外源ALA均能不同程度地降低白粉病处理下菊花的发病率和病情指数,提高了诱导抗病率;·O_(2)^(-)产生速率、H_(2)O_(2)含量、脂氧合酶(LOX)活性和丙二醛(MDA)含量显著降低;胆色素原(PBG)、原卟啉IX(Proto IX)、镁-原卟啉IX(Mg-Proto IX)、原叶绿素酸酯(Pchl)和叶绿素等含量显著提高,其中A1处理的上述指标均大于A2处理。A1处理的ALA溶液施加浓度以10 mg/L效果最佳,A2处理以25 mg/L效果最佳。综上,外源ALA可通过调节菊花的叶绿素合成途径来增强其对白粉病的抗性,试验结果可为阐明外源ALA介导的抗白粉病机制提供参考依据。

We used the cut flower Chrysanthemum morifolium Ramat.variety‘Shenma’as the material,and investigated the effect of ALA on the control of powdery mildew by two ways of exogenous ALA pretreatment and then inoculation with powdery mildew and simultaneous treatment of ALA and inoculation with powdery mildew(ALA concentrations of 0,0.1,1,10,25 and 100 mg/L).The results showed that compared with the 0 mg/L treatment,spraying suitable concentrations of exogenous ALA could reduce the incidence rate and disease index of Chrysanthemum morifolium Ramat.under powdery mildew treatments,improve the effect of induced resistance to the disease,significantly reduce the rate of·O_(2)^(-)production,H2O2 content,lipoxygenase(LOX)activity and malondialdehyde(MDA)content,and significantly increase the contents of porphobilinogen(PBG),protoporphyrin IX(Proto IX),Mg protoporphyrin IX(Mg-Proto IX),protochlorophyllide(Pchl)and chlorophylls.The above indicators of A1 were more than those of A2.The applied concentration of ALA in A1 was most effective at 10 mg/L,while the concentration of the A2 at 25 mg/L had the best effect.In conclusion,exogenous ALA enhanced resistance to powdery mildew by modulating the chlorophyll synthesis pathway in Chrysanthemum morifolium Ramat.The results of this study can provide a reference for further elucidation of the mechanism of exogenous ALA-mediated resistance to powdery mildew.