Gene Mapping And Function Analysis Of Two Suppressors Of Male Sterile Mutant Ms1-1 In Arabidopsis Thaliana

Male sterility is not only a hot spot in plant developmental biology,but also an important material basis of the utilization of rice heterosis.The popularization and application of hybrid rice have made an important contribution to grain yield in China,and the key point is selecting excellent male sterile line.Because of lack of maintainer lines,the nuclear male sterility which is not affected by light and temperature has made it harder to employ in production.In virtue of the homology relationship of PTC1 in rice and MS1 in Arabidopsis thaliana,together with research advantages of Arabidopsis thaliana as a model plant,we carried out a research of gene mapping and functional analysis of Sms1-98 and Sms1-61 suppressors of male sterility mutant ms1-1 in Arabidopsis thaliana.The main results are as following:1.Sms1-98 and Sms1-61 suppressors exhibit that the silique becomes longer but is slighter shorter than WT,the pollen is fertile but it also exists the condition of abortion and adhesion in pollen at the same time,bearing fruit normally but seeding setting rate is poor.Because of the delay of programmed cell death in tapetum and the abnormity in the process of microspore development from the beginning of the 8th stage of anther development,it caused that the fertility was not recoveried fullly.2.The results of allelic analysis showed that Sms1-98 and Sms1-61 were allelic mutants controlled by a single recessive gene.We carried on gene locataion of Sms1-98 suppressor by the whole genome sequencing combined with Mutmap analysis,the results showed that the linkage was implicated between fertility and the mutation location of SOP1(AT1G21580),which is a cofactor of the nuclear exosome and is involved in the degradation of partial abnormal m RNAs.Sequencing verification further confirmed that SNPs in different location altered in the first exon of SOP1 of Sms1-98 and Sms1-61,resulting in premature termination of transcription and translation.3.The results of genetic analysis was that sop1-5 could not suppress the fertility of MS1 T-DNA,but only complemented the sterility phenotype of ms1-1.In other words,SOP1 is not involved in direct regulation of MS1,but only changes the alternative splicing pattern of ms1-1.4.Alternative splicing analysis combined with RT-PCR experiments showed that in Sms1-98 and Sms1-61 mutants,the accumulation of specific transcripts and the presence or absence of different transcripts after alternative splicing were attributed to the effect of SOP1.5.GUS staining showed that SOP1 was a constitutive expression pattern,which was expressed in roots at young seedling stage,rosette leaves at seedling stage and anther of inflorescence at bolting stage.6.The results of salt treatment showed that the sensitivity of sop1-5 to salt stress at young seedling stage had no significant difference when compared with WT,but the salt tolerance of sop1-5 was less than WT at seedling stage.