Functional Analysis Of Arabidopsis SOP39 In Early Seed Development

FANTASIC FOURl-4(FAF1-4)and FAF-like belong to a new gene family with important functions in the maintenance of shoot and root meristems and negative regulation of ABA-signaling in Arabidopsis thaliana.The four FANTASTIC FOUR genes(FAF1-4)were previously descript as potential regulators of shoot meristem size in Arabidopsis thaliana.Overexpression of each FAF gene can represses WUSCHEL(WUS),which encodes a homeodomain transcription factor in cells of the organizing center(OC).WUS maintains non-cell autonomously stem cell fate in the cells above the QC.Beside its essential role as meristematic factors,WUS have crucial roles in ovule and stamen development.In contrast,loss of function of ENHANCER OF ABA CO-RECEPTOR1(EAR1,also known as FAF-like)exhibits pleiotropic ABA-hypersensitive phenotypes.Here we report the first developmental phenotype of a single mutant in a member of the FAF(-like)gene family.SOP39 belongs to the FANTASTIC FOUR family,so we expect it plays an important role in the growth and development of Arabidopsis thaliana.In a screen,we identified a potential RNA-null line carrying a T-DNA insertion site.There is no sop39 homozygous by genotyping,in heterozygous sop39-1/+and sop39-2/+siliques,approximately one quarter of the seeds were shriveled and had about 10 per cent of the size of mature wild-type seeds.sop39 homozygous are dead.,so the number of abortive seeds in mutant is much higher than that in wild type,and the ratio of abortive seeds to viable seeds conforms to Mendel's law of segregation.Genotyping identification was performed on the descendants of the single mutant of sop39/+from self-pollination and diplomacy to confirm the death of the homozygous mutant of sop39.SOP39::sop39-GFP transgenic plants recovered their abortive phenotype.In addition,in Arabidopsis thaliana tissues,the expression level of SOP39 in inflorescence meristem tissues is higher than that in root and stem tissues.These findings suggest a new crucial role of SOP39 gene family in for seed development.It is also suggested that the process of seed abortion should occur after fertilization,but not in a quarter of cases where a female gamete or male gamete fails.It also suggests that the FAF gene family also plays an important role in seed development.