The Research On The Function Mechanism Of Arabidopsis Transcription Factor PUIP2 Regulating Disease Resistance And Development Signal Pathway

The ubiquitination pathway is widely involved in regulating physiological activities including growth and development,hormone signaling transduction,disease resistance,and so on.Our preliminary work showed that the PUB13 protein containing U-box/ARM domain possesses E3 ubiquitin ligase activity could comprehensive regulation cell death,disease resistance and flowering time in Arabidopsis.In order to make clear of the PUB13 by which interaction protein to regulating these signaling pathways,our previous work filtered and verify the PUIP2 was PUB13's interacted protein,approved by structure analysis,PUIP2 is a basic helix-loop-helix(bHLH)transcription factor and it maybe participate in phytochrome signaling pathways.This thesis mainly studies in PUIP2 of which PUB13 mediated cell death,disease resistance,and the role of flowering time signal pathway,also the influence of light and the photoperiod to PUIP2.Main results for this study are as follows:1.PUB13 integrated with PUIP2 of regulating the plant and leaf size,flowering time in Arabidopsis under long day condition.The pub13puip2 double mutant under the condition of long sunshine has obvious blade decrease,plant dwarf phenotype.puip2 mutant showed an earlier flowering than Col-0,pub13puip2 double mutant extremely flowering time phenotype.Accordingly,the transcriptional level of flowering time positively regulator FT and SOC1 in pub13puip2 double mutant is significantly activated,the flowering time negative regulator FLC were greatly suppressed.2.PUB13 relies on PUIP2 to negatively regulate cell death and H2O2 accumulation in Arabidopsis.After the experiment of Trypan blue and DAB,the puip2 mutant basic undetectable cell death and the accumulation of H2O2,however,the accumulation area of cell death and H2O2 in pub13puip2 double mutant was remarkably decreased relative to pub13 mutant.3.PUB13 relies on PUIP2 to negatively regulate the resistance of biotrophic pathogen in Arabidopsis.Also,PUB13 is positively regulates the resistance of necrotrophic pathogen rely on PUIP2.Under long day conditions,puip2 shows decreased resistance against biotrophic pathogen Pseudomonas syringae pv.maculicola ES4326 and Pseudomonas syringae pv.tomato DC3000,but increased resistance against necrotrophic pathogen Botrytis cinerea.By detecting transcription level of disease resistance related gene,we found that PR1 in puip2 was suppressed,while the PDF1.2 in puip2 was enhanced obviously.However,the resistance strength of pub13puip2 double mutant was between pub13 and puip2.4.PUIP2 not only participates in the red light/far-red signal pathway,but also regulates the hypocotyl elongation relying on PUB13 in Arabidopsis.The puip2 mutant has a longer hypocotyl than Col-0 under the red light/far-red and blue light conditions.5.PUIP2 negative regulates the resistance of biotrophic pathogen in full light condition.The disease resistance of puip2 against biotrophic pathogen Pseudomonas syringae pv.maculicola ES4326 was suppressed,by detecting of the SA signaling pathways course of disease related gene PR1,we found that the transcription level of this gene was higher than Col-0.Conversely,the jasmonic acid/ethylene pathway's marker gene PDF1.2 in puip2 was obviously suppressed.These results show that PUIP2 was participated in which PUB13 comprehensive regulation the size of plant and leaf,flowering time,cell death and disease resistance response signal transduction in Arabidopsis,moreover,PUIP2 has the characteristic of photoperiodic dependence in disease resistance.In addition,PUIP2 involved in regulating the blue and red light/far-red signaling pathways.This provides important clues in analyzing PUIP2 in regulation of plant development,the function of cell death and disease resistance reaction.