Study On Transcriptome Sequencing Of Physcomitrella Patens Inoculate With Botrytis Cinerea

Physcomitrella patens is a model plant of non-vascular plant groups in a special evolutionary status.The whole genome has been sequenced,which is an ideal material for studying the evolutionary mechanism of disease resistance of land plants.At present,although a large number of studies have been reported on the disease resistance of Physcomitrella patens,they are all discussed in morphology,physiology and biochemistry.However,the studies on the transcriptome of Physcomitrella patens with Botrytis cinerea infection have not been reported yet.In this study,differential expression genes and metabolic pathways involved in defense mechanism with the infection of Botrytis cinerea were studied by transcriptome technique.The purpose of this study was to reveal the interaction mechanism between Physcomitrella patens and Botrytis cinerea,and to lay a scientific foundation for the comprehensive study of the evolutionary mechanism of the defense mechanism of land plants.The preliminary results of the study were as follows:1.The sequencing results of transcriptome analysis using bioinformatics methods showed that after inoculation with Botrytis cinerea for 12 h,1d,2d and 3d,the number of differentially expressed genes was 635,909,1449 and 2795,respectively.Among them,the percentage of up-regulated genes was 58.6%,62.9%,47.3%,30.8%,respectively.These genes increased firstly and then decreased as a result of inoculation with Botrytis cinerea.With the infection of Botrytis cinerea,the activity of plant decreased,and the defense reaction gradually declined.It was concluded that the defense response of Physcomitrella patens to pathogens probably occurred early in the interaction between hyscomitrella patens and pathogen.2.Differential gene analysis for specific periods showed that genes specially expressed in 12 h,1d,2d and 3d were 137,205,257 and 1733 respectively.Among them,the percentage of up-regulated genes was 52.6%,78%,51.4%,26.7%,respectively.The proportion of these up-regulated genes indicated that these genes may involved in its spontaneous,proactive defense response.After the inoculation with 1d,that physcomitrella patens may enter the peak of the autonomic defense reaction.These genes at 2d and 3d after inoculation may be declined for self-defense and self-repair of physcomitrella patens.There were 149 genes were all expressed at four times of inoculation.There were 119 genes only differentially expressed in 12 h,1d,and 2d;139 genes only differentially expressed in 1d,2d,and 3d;25 genes only differentially expressed in 12 h and 2d;38 genes only differentially expressed in 12 h and 3d;58 genes only differentially expressed in 1d and 3d;32 genes only differentially expressed in 12 h,1d,and 3d;and 43 genes only differentially expressed in 12 h,2d,and 3d.As shown by these data,the number of specific differentially expressed genes was higher as time goes on.It is suggested that the interaction between physcomitrella patens and Botrytis cinerea may be a continuous process.3.After physcomitrella patens inoculation of Botrytis cinerea,related genes of PTI(PAMP-triggered immunity)and ETI(Effector-triggered immunity)system were differentially expressed in different degrees.This results suggested that physcomitrella patens may resist the infection of Botrytis cinerea by activating the PTI system and ETI system.Some genes such as p53,salicylic acid(SA),jasmonic acid(JA)or ethylene(ET),auxin,cytokinin and abscisic acid(ABA)involved in signaling pathways,and so on were launched.In addition,phenylpropanoid biosynthesis related genes have been up-regulated or down-regulated in different degrees.It was suggested that physcomitrella patens may enhance the defense effect against Botrytis cinerea through phenylpropanoid metabolism,synthesis of lignans,flavonoids,stilbene and other polyphenolic compounds.