AtMBF1 GENES PARTICIPATE DURING THE GERMINTAION PROCESS MEDIATED BY ABA

ARCE, DÉBORA; GODOY, ANDREA VERÓNICA; VALLE, ESTELA MARTA; CASALONGUÉ, CLAUDIA

Rosario, Santa Fé, Argentina

Congreso; SAIB: XLII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biologia Molecular; 2006

Multiprotein bridging factor 1 (MBF1) is known to be atranscriptional co-activator that mediates transcriptionalactivation by bridging between an activator and TATA-boxbinding protein (TBP). MBF1 genes from Arabidopsis thaliana(AtMBF1a, AtMBF1b, and AtMBF1c) show distinct tissue-specificexpression patterns and responses to phytohormones.In this study, we carried out the analysis of different A. thalianaMBF1 mutant lines: T-DNA insertion mutant (Syngentacollection) and transgenic over-expressing lines for the threeAtMBF1 genes (a, b or c). AtMBF1abc triple mutant seeds, weretreated with different phytohormones (ABA, SA, Ethephon). AfterABA treatments triple mutant seeds showed a delay in thegermination rate compared to the wild type ones. However, theover-expressing lines (35S::AtMBF1 a, b and c) did not showdifferences on germination compared to the wild type under thedoses tested (0 till 2.5 uM ABA). On the other hand, SA orethephon treatments did not alter the germination responses. Allthese findings support a potential function of AtMBF1 genes onthe control of germination mediated by ABA. Supported byANPCyT, CONICET, UNMDP.