Transcriptional And Translational Characterization Of Rice Chitinase Genes

Background: Chitin is composed of the polymerization ofNAG(N-acetylglucosamine) by β-1,4glycosidic linkage. The study found chitin,especially chitin oligomers, can be used as a signal to stimulate plant defense responsesWhich is called microbe-associated molecular patterns. Chitin can be decomposed intooligomers or NAG by chitinase catalysis which played an important role of plantphysiology, biochemical processes, resilience, defensive reactions. Rice is one of the majorfood corps of human. Bacterial blight is one of the most serious rice bacterial diseases. It ismeaningful to understand chitinase transcription and expression characteristics in differentsamples of rice. Many studies have shown that there have regulations between expressionof rice chitinase regulation and rice pathogen defense response. This suggests chitinase isan important role of rice-pathogen interactions.Aim：Prepara rice chitinase protein antibodies.Integrated rice chitinase genestranscription information of growth and development and the process of rice-Xoointeraction. I detect the two processes chitinase protein expression patterns for found thebasis of depth understanding rice chitinase genes’ function.Materials and Methods: Rice93-11,4021, bacterial blight PXO99wild type, mutantbacterial blight fungus PXO99ΔraxST. Rice are infected by leave cutting with steriledistilled water as a control. Samples which extracted into protein sample for immunoblot(Western Blotting, WB) testing were collected at different time points after inoculation site.Polyclonal antibodies from Beijing Protein Research and Development Center Co., Ltd.Signal analysis by scaning χ ray films using ImageJ software.According chitinase proteinLocus number get the chitinase genes encoding protein sequence. multiple sequencealignment using ClustalW, phylogenetic analysis using Mega4.0, domain analysis usingSMART software. From the rice genome annotation project database download RNA-Seqgenerated FPKM (Reads per kilobase of exon model per million mapped reads) data foranalysis.Result:10Chitinase proteins expression profiling were surveyed using western blot(WB), it was found that the expression of CHIT5were down-regulated in normal growthrice leaves, while the expression of CHIT6, CHIT14, CHITC1and CHITC2wereup-regulated. In the incompatible interaction between rice and Xanthomonas oryzae pv. oryzae (Xoo), the expression of CHIT1, CHIT2, CHIT5, CHIT6, CHIT10, CHIT15andCHIT16were increased after inoculation and CHIT14, CHITC1and CHITC2showeddown-regulation. In addition, the comparison of chitinase protein expression in differentrice-Xoo interactions found similar alternation patterns between compatible andincompatible reactions, however, the extent of alterations were higher in incompatibleinteractions for most of chitinases. It is interesting to note that the expression of CHIT6was enhanced in mock-treated samples.Conclusion: Detection rice chitinase enzyme protein expression, only found fivechitinase protein expression in normal leaves. In incompatibility reaction in rice and Xoo10chitinase proteins’ expression change. CHIT1, CHIT2, CHIT5, CHIT10, CHIT15andCHIT16are induced. chitinase which are induced by blight inoculum suggest that theymay involve in disease resistance responses. There are three chitinase showeddown-regulation after vaccination which are CHIT14, CHITC1and CHITC2.That suggestthey may involve in negative regulation。CHIT6upregulated in the control (Mock) reactionwhich suggest that the expression of CHIT6may induced by mechanic wounding.