Auxin basipetal transport and accumulation in lower stems results in profuse formation of adventitious root primordia in aerial roots (aer) tomato (Solanum lycopersicum L.) mutant

FRANCESCO MIGNOLLI; MARÍA LAURA VIDOZ; LORENZO MARIOTTI; LEANDRO ANDRÉS COSSIO; LUIS A. MROGINSKI

Mar del Plata

Congreso; XV Congreso Latinoamericano XXX Reunión Argentina de Fisiología Vegetal; 2014

The tomato mutant aerial roots (aer) is characterized by a constitutive production of adventitious root primordia along the stem. So far, no attempts have been made in order to identify the possible factors that result in the aer phenotype. We observed that aer scions grafted onto wild type rootstocks were able to promote an increase in adventitious root elongation in wild type hypocotyls.This suggests that a factor moving from the aerial part of aer plants towards the hypocotyl is able to induce the emergence of adventitious root primordia. We therefore hypothesised that the accumulation of auxin (indole-3-acetic acid, IAA) exerts an inductive effect on aer adventitious root primordia initiation in hypocotyls and epicotyls. In order to ascertain whether the main factor that influences adventitious root primordia formation in aer is the apex-derived auxin that moves basipetally and accumulates in the lower part of the stem, the following experiments were carried out: 1) inhibition of auxin transport by stem application of 2,4,5-triiodobenzoic acid 2) removal of apical portion and lanolin application of IAA; and 3) analysis of endogenous IAA and its conjugates content in the apex, epicotyl and hypocotyl of aer and its wild type.