Preliminary Study On The Function Of GmSPL3 Gene Family In Soybean

Soybean [Glycine max(L.)Merr.] is an important food crop in China,the flowering time and plant morphology have great effect on grain yield.SPL3 is a member of SPL(SQUAMOSA PROMOTER BINDING PROTEIN-LIKE,SPL)transcription factor family.The microRNA156(miR156)could regulates the flowering time and plant morphology via targeting SPL genes in Arabidopsis thaliana,and AtSPL3/4/5 promote the flowering.However,the function of GmSPL3 in soybean remains unknown,therefore,studying the function of GmSPL3 gene is helpful to understand the molecular mechanism of the plant morphology and flowering regulation in soybean,and further support molecular assistant breeding.In this study,we generate GmSPL3 mutant in Williams82(W82)background by gene editing,and investigated the phenotype cause by GmSPL3 loss-of-function.We found:1.Four gene:GmSPL3a,GmSPL3 b,GmSPL3c,GmSPL3 d were the close homologous of AtSPL3.They share more than 50% similarities with GmSPL3 at amino acid level.And,the location analysis of SBP domain showed that GmSPL3 contained a conserved SBP domain,there were close to N-terminal,and two zinc finger structures and a nuclear localization sequence;2.qRT-PCR showed that the expression of GmSPL3 a in flower and shoot apex was higher,GmSPL3(b,c)was highly expressed in leaves,and GmSPL3 d was mainly expressed in trifoliolate leaf and shoot apex;3.In GmSPL3 knockout mutants,it was found that the flowering of spl3 abcd mutant lines were not significantly different from wild type W82 under LD or SD.However,spl3 abcd mutants showed the smaller leaves,fewer nodes,shorter internode length and lower plant height under SD,indicating that GmSPL3 played an important role in regulating the plants morphology of soybean.The results showed that GmSPL3 was a homologous gene of AtSPL3,but there were functional differentiation.In soybean,GmSPL3 did not regulate flowering time,but was involved in the regulation of plant type.