Characterization of the potato MADS-box gene STMADS16 and expression analysis in tobacco transgenic plants

A new MADS-box gene, STMADS16, has been cloned in Solanum tuberosum L. that is expressed in all vegetative tissues of the plant, mainly in the stem, b ut not in flower organs. STMADS16 expression is established early during ve getative development and is not regulated by light. Sequence similarity bes ides the spatial and temporal expression patterns allow to define a novel M ADS-box subfamily comprising STMADS16 and the gene STMADS11. Expression of the STMADS16 sense cDNA under the control of the 35S cauliflower mosaic vir us promoter modifies the inflorescence structure by increasing both interno de length and flower proliferation of the inflorescence meristems, and conf ers vegetative features to the flower. Moreover, STMADS16 ectopic expressio n overcomes the increase in flowering time and node number produced under s hort-day photoperiod, while the flowering time is not affected in long-day conditions. These results are discussed in terms of a possible role for STM ADS16 in promoting vegetative development.