Studies On The Role Of Hydrogen Peroxide In Interplant Wounding Signal Transduction Of P.simonii P.pyramidalis'Opera 8288'

We used P.simonii×P.pyramidalis'Opera 8277'as experiment materials. In order to discuss the role of hydrogen peroxide as the wounding signal transduction mediated by herbivory injuried among poplar, three treaments including Clostera anachoreta feeding, exposure to Methyl Jasmonic acid and feeding with inhibitor were applied to the poplar. At different times after treatments, measured the contents of hydrogen peroxide, the activities of antioxidant enzymes , the expression of genes between the wounded plant and the neibouring intact plant.The results showed that: The contents of hydrogen peroxide were appeared to rapidly increase in the herbivore-infested leaves and undamaged parts of herbivore-infested leaves, also increased in the neighbour health plants. And the antioxidant enzymes were also activated. We found that there was some signaling pathway within the damaged plant and interplant. Diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, could significantly inhibit H2O2 burst and enzymes activities that mediated by herbivore-infested. H2O2 has also been proved to play the signal role in defensive response. Jasmonate-signal transduction pathway is involved in the induction of plant defense in response to herbivore and pathogen attack. Treatment of poplar trees with gaseous methyl jasmonate (MeJA) induced the similar response with the caterpillars feeding, It could effectively induce plant defense response.It increased the contents of hydrogen peroxide, enhanced the levels and activities of defense-related protein Peroxidase (POD), Polyphenol oxidase (PPO) and Phenylalanine ammonia lyase (PAL).It can be concluded that methyl jasmonate is an important alarm signaling between plants.We used the Affymetrix Genechip microarray technique for analysis of gene expression profiles, it is a powerful strategy to identify gene expression in poplar leaves in response to herbivory by caterpillars (Clostera anachoreta). After 1 h of feeding, 334genes were classified as up-regulated, compared to 569 down-regulated. Functional classification of this induced gene set revealed genes with roles in general metabolism, photosynthesis, transport, transcriptional regulation and signalling, jasmonic acid signalling, response to stress, secondary metabolism, detoxification and redox processes. This study provides the first genome-scale approach to characterize insect-induced defences in a woody perennial providing large-scale transcriptional changes in solid platform for functional investigation of plant–insect interactions in poplar.