The Function Of Arabidopsis Copine Protein PUIP4 On Regulating Abiotic Stress And Development

lant U-box protein is highly conserved and usually possesses E3 ubiquitin ligase activity.Plant U-box protein exist in plant generally,and is involved in regulating multiple plant physiological proceedings.Our previous research found that Arabidopsis U-box protein PUB13 regulates plant size,growth and development,and disease resistance.To figure out the function mechanism of PUB13,yeast tow hybrid assay was proceeded and screened PUIP4 which is an interactor of PUB13.PUIP4 is a component of Copine protein family.To analyze the biological function of PUIP4 and its function in PUB13 regulated physiological processes,we made puip4,pub13 and pub13puip4 Arabidopsis mutants,and analyzed their phenotypes.The main results and conclusions are as follows:1.PUIP4 synergisizes with PUB13 to regulate plant growth and development.puip4 and pub13 plant sizes are smaller than wildtype,and pub13puip4 plant size even smaller than these two single mutants.puip4 and pub13 plant leaves are smaller than wildtype,and pub13puip4 plant leaves even smaller than these two single mutants.2.PUIP4 synergisizes with PUB13 to regulate plant immunity.puip4 and pub13 mutants are more resistant to bacterial pathogen Pseudomonas syringae pv.tomato DC3000 compared to wildtype,moreover,pub13puip4 plant is more resistant to DC3000 than puip4 and pub13 mutants.Correspondingly,the resistance related genes PR1 and PAD4 are activated in puip4 and pub13 mutants,and their expression is highest in pub13puip4 plant.In addition,we found that,the PTI(PAMP-triggered immunity)is stronger in puip4 and pub13 mutants compared with wildtype,and the PTI response is highest in pub13puip4 than puip4 and pub13.3.PUIP4 protein regulates Arabidopsis resistance to abiotic stress.puip4,pub13 and pub13puip4 were treated with high temperature,high salt and drought stresses.As a result,puip4,pub13 and pub13puip4 are more resistant to high salt and drought stresses compared with wildtype,and pub13puip4 is the most resistant plant.Interestingly,puip4,pub13,and pub13puip4 are more susceptible to high temperature stress,and pub13puip4 is the most susceptible.These data indicate that PUIP4 is involved in regulating multiple plant physiological proceedings,including plant growth and development,disease resistance and resistance to abiotic stresses.Furthermore,PUIP4 synergisizes with PUB13 to regulate these physiological proceedings,which provides more information to illuminate the mechanism of PUB13 function and study the physiological functions of copine proteins.