In: Phyton 54, Fasc. 2 (2014): S. 285-304 DOI: 10.12905/0380.phyton54(2)2014-0285

Key words: Antioxidant enzymes, Botrytis fabae, faba bean, phytohormones, salicylic acid, shikimic acid, Vicia faba, Fabaceae.

Summary

Aldesuquy H. S., Baka Z. A., Ababass M. A. & Nahla A. 2014. Control of chocolate spot infection of field beans by shikimic acid and salicylic acid: modulation of defense enzymes, phytohormones and simple phenols. – Phyton (Horn, Austria) 54 (2): 285–304.

This study investigated the effect of shikimic and salicylic acids at the concentrations of 0.4 and 0.7 mM, respectively, or their combination as phenolic compounds and Ridomil MZ at the concentration of 250 g/100 L as a fungicide on defense enzymes activity, different growth hormones and some phenolic compounds were quantified in Vicia faba leaves infected by Botrytis fabae. Pathogen caused noticeable increase in the activity of defense enzymes (i.e, peroxidase, polyphenol oxidase and phenyl alanine ammonia lyase) in infected faba bean plants. In the majority of cases, the applied phenolic compounds induced significant additional increase in such enzymes than that sprayed with fungicide. Moreover, this increment was concomitant with the increase in the endogenous total phenols, shikimic acid and salicylic acid content. With regard to hormonal changes, infection caused a massive increase in ABA content in faba bean plant accompanied by decrease in the growth promotors (GA3, IAA, total cytokinins, total growth promotors and promotors/inhibitors ratio). While, application of phenolic compounds appeared to alleviate this adverse effect by decreasing ABA content and increasing the growth promotors content.