Involvement of phenolic compounds in host resistance againstBotrytis cinereainleaves of the two commercially important kiwifruit (Actinidia chinensisandA. deliciosa) cultivars

Abstract

New Zealand Journal of Crop and Horticultural Science, 2003, Vol. 31: 221-233 Abstract Expression of phenolic compounds associated with constitutive and wound-induced resistance to Botrytis cinerea was studied in leaves of two kiwifruit cultivars, Actinidia chinensis 'Hort16A' and A. deliciosa 'Hayward'. Constitutive leaf resistance to B. cinerea was much greater in 'Hort16A' than in 'Hayward'. This resistance might be attributable, in part, to phenolic compounds, since phenolic extracts from non-induced 'Hort16A' leaves were significantly more fungitoxic than those from 'Hayward'. Fungitoxicity correlated positively with concentrations of three components in the phenolic fraction, one of which was identified as caffeic acid. Wounding and inoculation induced resistance in 'Hayward', but not 'Hort16A' leaves. Induction was accompanied by an increased concentration of a fourth component in the phenolic fraction, although this compound did not appear to be directly anti-fungal. This is the first study to examine the relationship between resistance against B. cinerea and phenolic compounds in leaves of the two main commercial kiwifruit cultivars, and results suggest that three phenolic compounds may contribute to constitutive resistance in 'Hort16A'.

Phenolic compounds in young developing kiwifruit in relation to light exposure: Implications for fruit calcium accumulation

“…Results on phenols were hard to compare with literature values because of the poor information existing on kiwifruit that mainly reports the leaf or mature fruit phenolic composition and associated with anti-fungal activity (Ippolito et al 1997, Greaves et al 2001, Wurms et al 2003. In general, excepting for the epicatechin of shaded fruitstalks and flavonols of berry, the pattern of phenolic compound changes showed a decrease within the early weeks after fruit-set.…”

“…This is the case with kiwifruit phenolic compounds. Extensive studies have been made on phenolic composition in the leaf and the mature fruit (Ferguson 1984, Ippolito et al 1997, Greaves et al 2001, Wurms et al 2003 as well as on the juice (Dawes & Keen 1999). These studies gave more emphasis to their health protective role against oxidative damage to the human cell (Chun et al 2005, Park et al 2006.…”

Susceptibility toBotrytis cinerea, and curing‐induced responses of lytic enzymes and phenolics in fruit of two kiwifruit (Actinidia) cultivars

“…Phenolic compounds were extracted by the Daayf et al (1997) procedure, modified for kiwifruit tissue as described by Wurms et al (2003), except that the aqueous phase containing conjugated phenolics was hydrolysed for 10 min (stem plug extracts) or 15 min (pericarp extracts) at 100°C in 2N HCl. Of the two phenolics fractions (free phenolics and acidhydrolysed phenolics) produced by this method, our analysis focused only on the acid-hydrolysed fraction, because earlier studies have demonstrated that this accounts for the majority of the anti-microbial activity (Daayf et al 1997;Wurms et al 2003).…”

“…Of the two phenolics fractions (free phenolics and acidhydrolysed phenolics) produced by this method, our analysis focused only on the acid-hydrolysed fraction, because earlier studies have demonstrated that this accounts for the majority of the anti-microbial activity (Daayf et al 1997;Wurms et al 2003).…”

“…A study of host resistance mechanisms against B. cinerea in leaves of 'Hort16A' and 'Hayward' demonstrated a higher level of constitutive resistance in 'Hort16A' leaves, and indicated involvement of antifungal phenolic compounds (Wurms et al 2003). An antifungal environment in the leaves helps to reduce inoculum loads at harvest that lead to subsequent fruit infections in storage, but the most important area for preventing fruit infections is the fruit tissue itself.…”