EFFECT OF CHANGING THE ENDOGENOUS CONCENTRATION OF AUXINS AND CYTOKININS AND THE PRODUCTION OF ETHYLENE IN PEA STEM CUTTINGS ON ADVENTITIOUS ROOT-FORMATION
Ma. Koukourikoupetridou et F. Bangerth, EFFECT OF CHANGING THE ENDOGENOUS CONCENTRATION OF AUXINS AND CYTOKININS AND THE PRODUCTION OF ETHYLENE IN PEA STEM CUTTINGS ON ADVENTITIOUS ROOT-FORMATION, Plant growth regulation, 22(2), 1997, pp. 101-108
Decapitation or treatment with naphthylphthalamic acid (NPA) - an inhi
bitor of IAA transport - or a synthetic cytokinin N-(2-chloro-4-pyridy
l)-N-phenylurea (CPPU) caused a decrease in rooting of pea cuttings. H
owever the mode of action of the above treatments was different. Decap
itation resulted in a decrease of indole-3-acetic acid (IAA) and a sim
ultaneous increase in cytokinin content at the base of the cuttings. N
PA decreased IAA even more, but did not influence cytokinins. CPPU alo
ne or in combination with amino-ethoxy-vinylglycine (AVG) - an ethylen
e biosynthesis inhibitor - increased IAA at the rooting zone, but CPPU
was transported from apex to the base of the cuttings where it inhibi
ted rooting. NAA, applied alone after decapitation, stimulated rooting
, probably partly by being an auxin, and partly by inhibiting the accu
mulation of cytokinins at the base of the cuttings. Treatment with AVG
neither influenced rooting nor auxin or cytokinin content. Therefore,
ethylene production does not seem to be one of the main factors invol
ved in the reduced rooting after the various treatments.