Auxin and Nitric oxide in plants responses to iron deficiency

RODRÍGUEZ COLMAN; M.J.1; COLMAN, S.1; NISHI, C.1; CORTI MONZÓN; G.1; QUIÑONES, A.1; ROBUSCHI, L.1; SALCEDO, F.1; GODOY, V.; LAMATINA, L. [1 CONTRIBUTED EQUALLY TO THIS WORK]

Rosario, Santa Fe

Congreso; Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Abstract Iron (Fe) is an essential micronutrient for plants. Arabidopsis thaliana responds with the type I strategy in Fe-deficient conditions. Strategy I response involves an induction of H+ -ATPasa (AHA2), ferric quelate reductase (FRO2) and the iron transporter (IRT1). It is known that many features of root physiology are controlled by hormones. Among them, auxin effects have been extensively studied in different root systems. The aim of this work was to studied the role of auxin in physiological, morphological and molecular responses induced by Fe-deficiency in Arabidopsis thaliana roots. Thereby, Arabidopsis seedlings were treated with the auxin naftil acetic acid (NAA) and the auxin transport inhibitor N-1-naphthylphthalamic (NPA). Seedlings were grown under Fe-deficient or sufficient conditions. Treatments with NPA indicated that increase of both nitric oxide (NO) levels and root hair density in response to Fe-deficiency, are under endogenous auxin control. In addition, results obtained by analyzing FRO2 activity and expression by semi-quantitative RT-PCR, indicate that both parameters are also under endogenous auxin control. It is concluded that endogenous auxin might be involved in A. thaliana root responses during Fe-deficiency.