Iron deficiency-induced responses in Arabidopsis thaliana roots: Role of ethylene

CABALLERO V; D'IPPÓLITO, SEBASTIÁN; MASSAZZA D.; NEGRI P.; RAMÍREZ L.; SCHROTT G.; TAGLIOTTI M.; PAGNUSSAT L.; PINEDO M.; LAMATTINA L.

Rosario, Santa Fe

Congreso; XLII reunión anual de SAIB; 2006

SAIB

A low iron availability in soil generates a series of plant root responses that lead to the increase ofiron uptake. Fe+3-reductase (FRO2) under the control of the transcription factor (FIT1) andmorphologic changes in roots have been described to be induced by iron deficiency. Sincedifferent reports have involved nitric oxide (NO) and ethylene in plant iron metabolism, wedecided to study the role of ethylene and its crosstalk with NO in plant root responses to irondeficiency. Plants of Arabidopsis thaliana grown in presence or absence of iron were treated withethephon (ethylene donor) or CoCl2 (ethylene synthesis inhibitor). The morphologic analysis ofthe roots showed that depletion of endogenous ethylene completely inhibited roots hairsdevelopment. NO production in roots was increased by ethylene treatment and decreased whenadding CoCl2. Beside, FRO2 and FIT1 expression were evaluated by semiquantitative RT-PCR.Results indicated that, while CoCl2 did not affect the FRO2 and FIT1 mRNA levels in presence orabsence of iron, the ethylene addition decreased those levels. In conclusion, ethylene would play arole in root hairs development and NO production and, at less extent, would also influence FRO2and FIT1 expression as well as FRO2 activity.*These authors have contributed equally to this work.