The involvement of phenolics and phytoalexins in resistance of potato to soft rot

Influence of Drought and Wounding Stress on Soluble Phenols and Proteins in Potato Tubers

“…These results may demonstrate, that the effect of drought stress on phenols is less evident, as noticed already for anthocyanins (Ac), peroxidases (POD) and the antioxidant capacity (Wegener & Jansen, 2013). Obviously, phenols as well as Ac and POD are far more involved in plant responses to biotic stress, such as pathogenic attack by microorganisms (Ghanekar et al, 1984) than in drought stress responses. The fact, that phenols were not strongly affected by drought stress can be seen as an advantage, because phenolic compounds contribute to the overall nutritional value of potatoes.…”

“…A similar differentiated wound-induced alteration of phenols has been reported for several cultivated and wild Solanum species (Wegener & Jansen, 2010). Based on their antimicrobial activity, plant phenols play a key role in pathogen defence (Ghanekar et al, 1984;Lyon & McGill, 1988;Weber et al, 1996) and as already mentioned they are precursors for lignin and suberin (Espelie et al, 1986;Vance et al, 1980). It is imaginable therefore that in tissue of cv.…”

Effect of calcium soil amendments on phenolic compounds and soft rot resistance in potato tubers

“…They have antibacterial effects and inhibit growth of soft rot bacteria (Ghanekar et al, 1984;Kumar et al, 1991). Chlorogenic acid is produced as a defense in potatoes in response to infection or injury (Ghanekar et al, 1984).…”

“…Chlorogenic acid is produced as a defense in potatoes in response to infection or injury (Ghanekar et al, 1984). Caffeic acid is known to inhibit the growth of soft rot bacteria (Kumar et al, 1991).…”

Differential activation of potato 3-hydroxy-3-methylglutaryl coenzyme A reductase genes by wounding and pathogen challenge.

“…Recently, we showed that Ecc inoculated onto potato tuber slices induces phenylalanine ammonia-lyase (PAL) mRNA and enzyme activity more rapidly and to greater levels than with wounding alone (Yang et al, 1989). Ecc also induces accumulation of sesquiterpenoid phytoalexins in potato tubers (Ghanekar et al, 1984). Resistance based on induction of proteins may be important to the host in restricting pathogenesis in nonstressed tubers; however, under hypoxic conditions that are especially conducive to soft rot, protein synthesis does not occur (Vayda and Schaeffer, 1988).…”