Is zinniol a true phytotoxin? Evaluation of its activity at the cellular level against Tagetes erecta

Journal of General Plant Pathology (Impact Factor: 0.97). 04/2010; 76(2):94-101. DOI: 10.1007/s10327-010-0222-9


Zinniol, a non-host selective phytotoxin commonly produced by fungi of the Alternaria genus, has been reported as the metabolite responsible for the phytotoxicity of the lipophilic fraction of A. tagetica. While both the lipophilic fraction and zinniol have been shown to produce necrosis on leaves of susceptible marigold (Tagetes erecta) plants, the true role of zinniol in the infectious process remains uncertain. Using marigold cell cultures as a model, we
evaluated the effects of zinniol and the lipophilic fraction at the cellular level and showed that pure zinniol is not markedly
phytotoxic at concentrations known to induce necrosis in leaves of T. erecta. Moreover, the effects of zinniol on cell membranes and DNA fragmentation are less intense than those caused by the lipophilic
fraction. These results suggest that zinniol may not play a significant role in the A. tagetica–T. erecta interaction and, consequently, its classification as a non-host selective phytotoxin is questionable.

Alternaria tagetica
-Host-selective phytotoxins-Non-host selective phytotoxins-Programmed cell death-Reactive oxygen species-
Tagetes erecta

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Available from: Joaquín Qui
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