Interaction of abscisic acid and indole-3-acetic acid-producing fungi with Salix leaves

Abstract

The molds Botrytis cinerea, Cladosporium cladosporioides, and the yeast Aureobasidium pullulans, isolated from the leaves of three short-rotation Salix clones, were found to produce indole-3-acetic acid (IAA). Abscisic acid (ABA) production was detected in B. cinerea. The contents of IAA and ABA in the leaves of the Salix clones and the amounts of fungal propagules in these leaves were also measured, in order to evaluate whether the amounts of plant growth regulators produced by the fungi would make a significant contribution to the hormonal quantities of the leaves. The content of ABA, and to a lesser degree that of IAA, showed a positive correlation with the frequency of infection by the hormone-producing organisms. The amounts of hormone-producing fungi on leaves that bore visible colonies were, however, not sufficiently high to support the claim that either the fungal production of ABA or IAA would significantly contribute to the hormonal contents of the leaves of the Salix clones. It is therefore suggested that the effect of fungal IAA production on plants is limited to the rhizosphere and that B. cinerea, which is a known pathogen, induces ABA production by the mother plant as a response to physiological stress.

The effect of calcium on the production of ethylene and abscisic acid by fungus Fusarium culmorum and by wheat seedlings infected with that pathogen

“…The content of this compound was much higher in diseased seedlings and it finds confirmation in literature. It was demonstrated both in plants inoculated with fungi (Kriesel 1991, Tuomi et al 1993, bacteria (Steadman and Sequeira 1970) and viruses (Whenham et al 1986). It follows from the investigations carried out by Stopifiska (1994) on poplar clones with different resistance to Ceratocystis fimbriata that resistant clones contained less ABA than susceptible ones.…”

Potential of yeasts as biocontrol agents of soil-borne fungal plant pathogens and as plant growth promoters

“…Yeasts have been reported to produce PGRs such as ethylene (Lynch 1972), GA 3 (Krassilnikov 1963;El-Tarabily 2004), IAA (Nakamura et al 1991;Tuomi et al 1993;El-Tarabily 2004;Nassar et al 2005), and IPYA (Nassar et al 2005). The reports by Krassilnikov (1963), Nakamura et al (1991), and Tuomi et al (1993) dealt only with the production of PGRs in vitro with no attempts to evaluate these yeast isolates for plant growth promotion under glasshouse or field conditions. Polyamines such as putrescine, spermidine, and spermine have been implicated to play vital roles as modulators in a variety of growth, physiological, and developmental processes in higher plants (Galston and Kaur-Sawhney 1990).…”

Biosynthesis and metabolism of abscisic acid in tomato leaves infected with Botrytis cinerea

“…Although the role of ABA in plant diseases remains to be established, increasing evidence from studies on infected plants suggests that ABA is involved in the interaction between phytopathogenic microorganisms and their host plants. Increased levels of endogenous ABA have been reported from various plant species in response to infection with fungi, bacteria and viruses (Steadman and Sequeira 1970;Pegg 1976;Kern 1985;Whenham et al 1986;Tuomi et al 1993). Furthermore, ABA levels were found to increase in roots of maize colonized by vesicular arbuscular mycorrhizas (Danneberg et al 1992).…”