Arabidopsis Thaliana SPT16 Gene Affects The Development Of Anther Development Patterns

The facilitates chromatin transcription(FACT)complex is histone chaperone that promote the elongation of transcription by destabilizing nucleosomes.In plants,FACT comprises SPT16 and SSRP1 subunits which are conserved proteins.SPT16 was reported to affect both vegetative and reproductive development in Arabidopsis.However,the molecular mechanism involved is still unclear.Here,we purchased Arabidopsis seeds of line CS805649 that harbours mutation in the gene encoding the SPT16 protein from ABRC.Compared with that in the wild-type,expression level of SPT16 was reduced,and the mutant plants show defects in male organs.Cytological observation indicated that anther development in spt16 mutant exhibited defective inner somatic cell layers and sporocytes at a very early anther development stage.The spt16 mutant also displayed abnormal microsporangia development and severely reduced male fertility with the mutant plants setting very few seeds.Genetic analysis indicated that the mutant plant phenotype is controlled by a single recessive nuclear gene.Gene mapping analysis showed that two T-DNA copies with the right arms back to back were present in promoter region of At4g10710 gene on chromosome 4.Linkage analysis results showed that insertion of the T-DNAs is closely linked to the mutant male sterelity phenotype.So it is the mutation of SPT16 gene leads to the spt16 mutant male sterility.In situ hybridization eperiment showed that SPT16 was predominantly expressed in the stamen primordia,the archesporial cells as well as in the sporogenous and parietal cells.Therefore,our study reveals that SPT16 plays an important role in microsporangium development and anther patterning formation during early anther development in Arabidopsis.