Role of AtHscB in mitochondria iron metabolism in A. thaliana plants

LEADEN, L.; MARTÍN, M.; BUSI, M.V.; GOMEZ-CASATI, D.F

Rosario

Congreso; 8th International Conference for Plant Mitochondrial Biology,; 2013

Comité Organizador Argentino

Iron is an essential nutrition element in all organisms being fundamental to mitochondria and chloroplasts metabolisms. Iron-sulfur (Fe-S) clusters are produced inside both organelles and the assembly and maturation of Fe-S proteins require a complex cellular machinery. In our laboratory we have characterized A. thaliana transgenic lines overexpressing AtHscB (a co-chaperone involved in the Fe-S cluster biogenesis in mitochondria). However these lines grow on normal iron conditions, they show an impaired translocation of Fe from the roots to the shoots resulting in altered iron content, metabolism, and distribution. In addition, the induction of ferroquelate reductase (FRO2) activity in these plants is in agreement with the deficit of iron sensing. . We also evaluate the effect of the deficiency of AtHscB on iron metabolism in A. thaliana plants studying two AtHscB knock down mutant plants (mh1 and mh2). We determine FRO2 activity in mh1 and mh2 mutants grown under normal or iron deficient conditions. Results show that FRO2 activity is similar in wt plants in both conditions and it does not change even when mh1or mh2 mutants were grown on iron deficient conditions. Furthermore, the mutant lines are more resistant to iron deficiency but show an increased iron content in roots and shoots. Our results suggest that AtHscB could respond to changes in iron metabolism and the deficiency of AtHscB might produce an alteration of the iron transport between roots to shoot.