Comparative Analysis Of The Function Of JAZ Family Genes In Rice And Arabidopsis

Jasmonic acid(JA)is a small but highly effective organic signal molecule that affects plant life activities,and regulates the process of plant growth,development and stress response.Jasmonic acid can be found in everything from cell cycle and trichome formation to aging response and pathogen defense.JAZ is the key to jasmonic acid signal transduction.After forming a receptor complex with COI1,JAZ can release MYC2,thereby initiating the transcription of downstream target genes.The functions of theJAZ family in the model plant Arabidopsis have been widely reported,but little research has been done on the riceJAZ family.Rice is one of the most important food crops in the world,and bacterial diseases are one of the factors that seriously threaten rice yield.Analyzing rice hormone signaling pathways and identifying high-quality rice functional genes have good research significance and application prospects in the production of food crops.In order to systematically reveal the functions of riceJAZ family genes,this study carried out homology analysis on 13 OsJAZ proteins and 12 AtJAZ proteins;In order to deeply analyze the effects of OsJAZ and AtJAZ on plant growth process and bacterial resistance,13 kinds of OsJAZ ectopically expressed Arabidopsis transgenic plants(OsJAZ OE)were produced in this study,and 12 kinds of AtJAZ overexpressed Arabidopsis thaliana plants(AtJAZ OE)for further investigation;In this study,a strain OsJAZ11 OE with significant bacterial resistance was screened out by comparing the phenotypes of flowering period,JA tolerance,and pathogen resistance between OsJAZ OE and AtJAZ OE.In addition,this study further produced a rice transgenic plant OsJAZ11 OV which overexpressing OsJAZ11,and analyzed its resistance to RS105.It was found that OsJAZ11 can be used as a high-quality candidate gene for breeding resistant rice varieties.The main results are as follows:(1)JAZ proteins in rice and Arabidopsis have extremely high homology.In this study,phylogenetic trees of 13 OsJAZ proteins and 12 AtJAZ proteins were constructed and the motifs of the proteins were analyzed.The results showed that theJAZ proteins of rice and Arabidopsis were similar in structure and clustered tightly in the phylogenetic tree.In addition,JAZ proteins which clustered more tightly in the phylogenetic tree have similar functions in plants,such as AtJAZ10 and OsJAZ5,AtJAZ3 and AtJAZ4,AtJAZ5 and AtJAZ6.(2)Similar to AtJAZ OE plants,most OsJAZ OE plants changed in flowering stage.Among them,OsJAZ3,-4,-5,-8,-9,-10 and-11 OE plants had a significant early flowering phenotype,and OsJAZ1,OsJAZ4-2 and OsJAZ12 OE plants showed delayed flowering.Transcript analysis showed thatJAZ regulated the flowering days of Arabidopsis by affecting the expression of FT,and the expression of FT in the early flowering phenotype plants was significantly higher than that in the wild type.Y2 H analysis showed thatJAZ protein interacted with DELLA protein,and the corresponding transgenic plants flowered earlier.(3)OsJAZ11 has the highest tolerance to jasmonic acid.The study found that there was a significant difference in root length betweenJAZ OE plants and wild-type plants.When Arabidopsis was grown on a medium containing 50 μM Me JA,the root length of OsJAZ11 OE plants was significantly longer than that of other plants.The fluorescence detection results of GFP in the root tips of seedlings showed that after exogenously applying 1 μM Me JA,the fluorescence brightness of the fusion protein in OsJAZ11 OE plants was the highest,which was consistent with the jasmonic acid tolerance phenotype.(4)Among the 25JAZ OE plants,only OsJAZ11 OE had increased bacterial resistance compared with the wild type.Compared with otherJAZ OE plants and wild type,the salicylic acid response gene PR1 was significantly up-regulated in OsJAZ11 OE after inoculation,and the jasmonic acid response gene PDF1.2 was continuously suppressed.(5)There are many homologous and heterologous interactions between OsJAZ.Y2 H analysis showed that some OsJAZ could form homodimers or heterodimers,and Bi FC analysis further verified that both OsJAZ6 and OsJAZ7 could interact with OsJAZ11 in the plant nucleus.(6)The resistance of OsJAZ11 OV rice transgenic plants to RS105 was significantly higher than that of the wild type.After overexpressing the screened strong jasmonic acid inhibitor OsJAZ11 in rice plants,the bacterial resistance of the transgenic plants was significantly higher than that of the wild type.It shows the reliability of this study and the potential of OsJAZ11 as a key gene for genetic breeding.This study aimed to explore the commonalities and characteristics of differentJAZ proteins from the perspective of genetics.In this study,the economically valuable gene OsJAZ11 was quickly,efficiently and inexpensively screened out in Arabidopsis,and then verified in rice.In conclusion,the results of this study provide ideas for further analysis of the function of riceJAZ family proteins.