Tomato Aux/IAA3 and HOOKLESS are important actors of the interplay between auxin and ethylene during apical hook formation.

Salma Chaabouni (1) , Alain Latché (1) , Jean-Claude Pech (1) , Mondher Bouzayen (1)

1 GBF - Génomique et Biotechnologie des Fruits

Plants implement differential cell growth as an adaptation process in order to direct their development in a way that allow them to better cope with the environmental conditions. This process requires the complex integration of multiple hormone signalings, though, a lot remain to be known about the mechanisms and the molecular actors that take part in this hormonal dialogue. We have previously shown that Sl-IAA3, an Aux/IAA gene, is a molecular link between auxin and ethylene responses in tomato plants. We show here that the expression of Sl-IAA3 in etiolated seedlings is restricted to the inner side of the apical hook, opposite to that of the HOOKLESS gene whose loss-offunction mutation results in the absence of hook formation. We propose a model on how auxin and ethylene modulate the expression of Auxin Response Factor 2 (ARF2) via IAA3 and HLS protein to regulate hypocotyl bending.

Mots clés: Transcription factors; Apical hook; Hormone signaling; Auxin/ethylene cross-talk; Tomato

Domaines: Amélioration des plantes

Salma Chaabouni, Alain Latché, Jean-Claude Pech, Mondher Bouzayen. Tomato Aux/IAA3 and HOOKLESS are important actors of the interplay between auxin and ethylene during apical hook formation.. Plant Signaling and Behavior, 2009, 4 (6), pp.559-560. ⟨10.4161/psb.4.6.8748⟩. ⟨hal-03476646⟩