FINDING MAST ER MOLECULAR REGULATORS OF INFLORESCENCE ARCHITECTURE IN Brachypodium distachyon

UBERTI MANASERO NORA; A. C. VEGETTI; REINHEIMER R.

Rosario

Congreso; SAIB; 2014

Grasses produce florets on a structure called a spikelet, and variation in the number and arrangement of both branches and spikelets contributes to the great diversity of grass inflorescence architecture. In Brachypodium, the inflorescence is an unbranched spiciform raceme with a terminal spikelet and a limited number of lateral spikelets. Spikelets are indeterminate and give rise to a variable number of florets. To gain insight into the genetic regulation of Brachypodium inflorescence development and architecture, we characterized T-DNA insertional mutants with altered expression of inflorescence genes. Compared to wild type, BdLFY mutants develop more spikelets supported by shorter internodes. Flower and seed development seems to be normal, suggesting that BdLFY regulates the fate of spikelet rather than floral meristem, as it counterpart in Arabidopsis. Similarly, BdPAP2 mutants shows increased branching and a slightly delay in transition from vegetative to inflorescence meristem. A stronger delayed in flowering time was observed in BdRCN mutants, since the transitional state in this mutants correspond to completely developed flowers in wild type plants. The results presented here will be helpful to understand the molecular basis of Brachypodium inflorescence development and even to elucidate master genes responsible for the high diversity of inflorescences observed in grasses.