The tomato floral homeotic protein FBP1-like gene, SlGLO1, plays key roles in petal and stamen development

MADS-box transcription factors play important role in plant growth and development, especially floral organ identities. In our study, a MADS-box gene SlGLO1- tomato floral homeotic protein FBP1-like gene was isolated. Its tissue-specific expression profile analysis showed that SlGLO1 was highly expressed in petals and stamens. RNAi (RNA interference) repression of SlGLO1 resulted in floral organ abnormal phenotypes, including green petals with shorter size, and aberrant carpelloid stamens. SlGLO1-silenced lines are male sterile. Total chlorophyll content was increased and chlorophyll biosynthetic genes were significantly up-regulated in SlGLO1-silenced petals and stamens. Furthermore, B-class genes expression analysis indicated that the repressed function of SlGLO1 led to the enhanced expression of TAP3 and the down-regulation of TPI in the petals and stamens, while the expression of TM6 was reduced in petals and increased in stamens and carpels of SlGLO1-RNAi plants. Additionally, pollen grains of transgenic lines were aberrant and failed to germinate and tomato pollen-specific genes were down-regulated by more than 90% in SlGLO1-silenced lines. These results suggest that SlGLO1 plays important role in regulating plant floral organ and pollen development in tomato.