Age-related loss of rooting capability in Arabidopsis thaliana and its reversal by peptides containing the Arg-Gly-Asp (RGD) motif.
We describe here an experimental system to study the age-related decline of adventitious root formation in Arabidopsis thaliana L. (Heynh), ecotype Landsberg erecta (Ler). The system is based on the different rooting capacity of hypocotyls from de-rooted juvenile (12-day-old) and adult (26-day-old) plants. Hypocotyls from de-rooted juvenile plants rooted readily within a week of culture, and the rooting process was not dependent on exogenous auxin. In contrast, hypocotyls from de-rooted adult plants rooted poorly and only after longer periods of time. Exogenously applied auxin had no effect on rooting of hypocotyls from de-rooted adult plants. Rooting capacity, although correlated with the transition to flowering, did not depend on this transition. Root induction declined in a similar manner when the transition to flowering was delayed, either genetically with the fve mutant or physiologically with short days. The results showed that rooting of hypocotyls from de-rooted adult plants depended on the effect of peptides containing the RGD motif. Both the percentage of rooting and the number of roots were largely increased when the hypocotyls were treated transiently with the RGD peptide. The effect of the RGD peptide was a necessary, but not sufficient, condition for rooting of hypocotyls from de-rooted adult plants.
Díaz-Sala
Carmen
C
Department of Plant Biology, University of Alcalá, ES-28871, Alcalá de Henares, Madrid, Spain 1Present address: Barberet & Blanc S.A., Camino Viejo, 205 ES-30890, Puerto Lumbreras, Murcia, Spain.
Garrido
Germán
G
Sabater
Bartolomé
B