Cloning And Functional Analysis Of A Flower-Enriched Gene GmMYB181in Soybean

Soybean (Glycine max (L.) Merr.) is one of the most important economical crops, as it is the main source for vegetable oil and protein. The reproductive growth directly affects crop seed yield and quality, to unravel the genetic mechanisms underlying the regulation of flower development is of great significance in improvement of soybean production. The MYB gene family comprises one of the bigest groups of transcription factors in plants. MYB transcription factors are involved in plant development, secondary metabolism, hormone signal transduction, disease resistance and abiotic stress tolerance, play an important role in the built form of flowers and other organsAccording to previous results of the soybean genome chip array (GeneChip(?) Soy Genome Array, Affymetrix)in our laboratory, several flower-enriched genes were identified. One of these isolated flower-enriched genes has already been named as GmMYB181in soybean flowers. RT-PCR and subcellular localization were used to isolate cDNA sequence of GmMYB181gene and to analyze expression in plants and cellular localization. The transcriptional activation ability of the MYB proteins were detected by yeast expression system. Overexpression of GmMYB181in Arabidopsis thaliana was performed to understand the mechanism for floral development. Major results are:1. Gene isolation and sequence analysisIn this study, we have isolated GmMYB181gene from soybean genome in silico. The GmMYB181contained a624bp open reading frame, encoding a204amino acid protein. Sequence comparison showed that GmMYB181was similar with other MYB proteins.2. Expression analysis of GmMYB181Real-time quantitative PCR and Semi-quantitative RT-PCR were used to analyze the expression patterns of GmMYB181in soybean. Tissue-specific expression patterns analysis showed that GmMYB181gene exclusively expressed in flower organ. GmMYB181was anucleus localized transcriptional activator, suggesting it functioned as a transcription factor in gene regulatory network.3. Phenotypic analysis of GmMYB181transgenic Arabidopsis thalianaBy using Gateway technology, we constructed over-expression vector of GmMYBl81to investigate its functions. Then we transferred it into Arabidopsis thaliana. Over expression of GmMYB181in Arabidopsis altered the morphology of flower fruit and plant type. Sepals were revoluted in35S::GmMYB181transgenic plant. Transgenic siliques were significantly smaller than wild type. Transgenic plants become dwarfing. These results indicated that GmMYB181was involved in floral development, may play an important role during development of fruit and plant type.