Prmt5 Regulates Alternative Splicing And Function Of Photorespiration Related Genes Under Various Stress Conditions

When plants encounter different stresses,the expression of different stress response genes will be induced.Therefore,gene expression regulation plays an important role in plant stress response.Alternative splicing has played an important role in the gene expression regulation at the post-transcriptional level.PRMT5,an protein arginine methyltransferase,is also a splicing-associated protein.Mutations in PRMT5 can cause changes in the splicing pattern of a large class of genes,including some photorespiration genes such as RCA,HPR,GDCH1,and so on.In this study,RNA-seq technique was applied to analyze the changed splicing pattern of photorespiration-related genes induced by different stresses in Col-0 and prmt5-2.A large number of primers was designed to detect alternative spliced transcripts of photorespiration-related genes under different stresses.And the changes of splicing patterns of photorespiration-related genes under different stresses was analyzed.The possible function of photorespiration related gene At GDCH1 was discussed.The CRISPR/Cas9 gene editing technology was used to obtain the homozygous rice plants of Os PRMT5,and the differential alternative spliced transcripts of photorespiration related genes under stress was detected.The experimental results are as follows: 1.Under the high light density or high concentration carbon dioxide treatment,a largenumber of genes in Col-0 enduring differentially alternative splicing,and prmt5-2produces more differentially alternative spliced transcripts than Col-0,especiallytranscripts with intron retention,which are twice as many as Col-0 in prmt5-2.Amongthem,more alternative splicing events of photorespiration-related genes were alsoinduced in prmt5-2,and intron retention was still the mainly alternative splicing type of these events.2.Photorespiration-related genes such as GDCH1,GLT1,GS1.4,AGT,10-FDF,GGAT2,HAOX2,PGLP1,HPR2 and RCA were verified in Col-0 and prmt5-2 under differentstresses,The difference of alternative splicing pattern was found,and the alternativesplicing patterns under different stress conditions are specific.3.Six kinds of transgenic homozygous plants are gained by overexpressing those threedifferent transcripts of At GDCH1,but overexpression of At GDCH1 transcripts had littleeffect on the phenotype of Arabidopsis.Western blot analysis showed that all thetransgenic plants had higher protein content than the wild type,but new proteins was notdetected in all those plants overexpressing intron-containing transcripts.4.The gene editing vector of rice Os PRMT5 was constructed,and the transgenichomozygous plants edited by CRISPR/Cas9 were obtained.Under different stress,Mutation of Os PRMT5 gene induced the differential alternative splicing ofphotorespiration-related genes,indicating that PRMT5 has similar functions in regulatingalternative splicing of photorespiration-related genes in rice and Arabidopsis.