Identification of downstream targets of AtERF019 transcription factor in drought stress

VALLE EM; ZANOR MI; SCARPECI TE

Cordoba

Congreso; SAIB 2016 LII Reunión Anual; 2016

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

AtERF019transcriptionfactor, which is a member of the APETALA2 (AP2)/ETHYLENE RESPONSE FACTOR (ERF)gene family, was induced under oxidative stress originated in chloroplast.Adult plants overexpressing AtERF019 (ERF019 lines) showed enhanceddrought tolerance compared to Col-0 plants. This tolerance could be explained in part by a lower transpirationrate in ERF019 lines owed to smaller stomatal aperture and lower cell wallpermeability. Using a proteomic approach, the branched-chain-amino-acid aminotransferase 3 (BCAT3),aprotein known to be produced in response to stress, was identified in ERF019 lines under control condition. This enzyme is plastidlocalized and is involved in both BCA and glucosinolate synthesis. Additionally, a bcat3mutant was more sensitive to drought stress than Col-0. Several genes encodingproteins present in ERF019 control or drought conditions but not in Col-0plants were predicted to be targets of AtERF019. Among them are thetranscription factor OXS2 and genes relatedto cell wall metabolism. These data indicate that a number of responsesinvolving the cell wall appear to be important in adapting cells towater-deficit stress.