Phenylpropane Metabolic Research Of Pinus Massoniana Infected By Bursaphelenchus Xylophilus

Bursaphelenchus xylophilus is a pinus destructive disease which is caused by pine nematode (Bursaphelenchus xylophilus), of pine plays an important role in the anti-susceptible disease mechanism of pine trees,can form anti-disease secondary metabolites such as phytoalexin,lignin and phenolic compounds and so on, therefore,be considered as one of the important mechanisms that plant enhance disease resistance.In this paper,mainly aim the important role of phenyl propane metabolism in bursaphelenchus xylophilus to do the following research.(1) Phenyl propane metabolic effects of pinus massoniana infected by pine nematode.Benzoic acid, salicylic acid and phenylacetic acid are direct and indirect production of pine phenyl propane metabolism,and its content in pinus massoniana changed obviously in the infected process of pine nematode, The results showed that after infected by pine nematode,the content of three types of organic acid benzoic acid, salicylic acid and phenylacetic acid growth steadily,the variation trend of benzoic acid and salicylic acid content is similar,raise after infection,decreased after infected seriously ill (the twelfth day),while the content of phenylacetic acid continue to rise, declined before infected seriously (the ninth day), Numerous studies show that plants can transform phenylacetic acid into benzoic acid,and benzoic acid can be converted into salicylic acid affected by benzoate hydroxylase,salicylic acid can improve the system of plant disease resistance,all three things play an important role in anti-susceptible disease process of, In the infected process of pinus massoniana, research showed that the activity of phenylalanine ammonia-lyase and peroxidase raise continually,decreased after infection,the activity of polyphenol oxidase also increased,however,the activity of catalase-declined, The change of enzyme activity reflects aggravation of disease,but also reflects the body's defense gene expression continued to increase after infected by pine nematode,These types of enzymes resisted pathogen in the anti-susceptible disease process,in early stage of disease,if these types of enzymes showed relatively strong activity,the pines may be able to prevent the disease from getting worse, Both of the content of and H2O2 increased continually after infection,that is a resistant performance of pinus massoniana,the enhance of content of lignin improve the ability of plants resisted disease,H2O2 is an active oxygen produced by biological cell metabolism,on the one hand,it poisoned pine cell and caused allergic reaction,on the other hand it can restrict and blockade the growth of nematodes, The varying characteristic of Phenyl propane metabolite of infected pinus massoniana has special significance in the study of prevention and control of bursaphelenchus xylophilus and breeding for disease resistance of pine. (2) Separation and Purification and fundamental properties research of benzoic hydroxylase and salicylate hydroxylase.Benzoic hydroxylase and salicylate hydroxylase in pinus massoniana have separated and purified through cellulose (DE52) column chromatography and DEAE-Sephacel column,the two the molecular weight of enzyme were 43.58 KD and 46.68KD respectively measured by SDS-polyacrylamide gel elect ropho-resis, study found that different pH values and metal ions can impact the activity of these two enzymes, Research of the activity of these enzymes in pinus massoniana which infected by pine nematode showed that the activity of benzoic hydroxylase continued to rise,peaked at the ninth day before infected seriously,and declined continually in the following days, The experimental results show that benzoic hydroxylase in pinus massoniana play an important role in the anti-susceptible disease process,the content increase of benzoic acid probably due to the inhibition of enzyme activity, The activity of salicylate hydroxylase continued to decrease and was lower than the control plant, only increased slightly in 12d and 18d,just little higher than the control plant,the activity of salicylate hydroxylase changed unobviously,whether the activity impacted the morbidity of pinus massoniana need further experimental verification.