Study of mitochondrial proteins engaged in growth and defense in Arabidospsis thaliana

MENCIA R; WELCHEN E

Congreso; LII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB); 2016

The aim of our group is to elucidate the mechanisms through which mitochondria perform non canonical functions associated with hormonal growth control and pathogen defense in plants. We identified a family of new proteins involved in defense mechanisms against oxidative stress in Arabidopsis. Plants overexpressing (OE) one of our candidates exhibit interesting phenotypic characteristics like larger size, higher biomass and increased resistance to pathogen infection compared to wild type (WT) plants. As was previously observed in yeast and humans, by confocal microscopy we demonstrated that our protein is also specifically localized in plant mitochondria under control growth conditions. Interestingly, plants with modified expression levels of this protein exhibit altered content of hormones like Citokinins (CK) and Salicylic acid (SA). Furthermore, by using a combination of plants with different backgrounds (ahp1,2,3,4; arr3,4,5,6,7,8,9; ipt3,5,7; oeCKX2, oeCKX1, pCKX1:GUS) we demonstrated that the sensitivity and signaling pathways of these hormones are also modified in our plants. We conclude that our protein of interest constitute another example regarding to the interplay between mitochondrial activities, hormonal control of growth and defenses in plants.