Variations in the Phenolic Contents of Cocoyam Clones in Correlation to Resistance to Pythium Myriotylum
Phenolic compounds from leaves and roots of infected and healthy cocoyam clones resistant (RO1075), tolerant (RO1043), and susceptible (RO1157) to Pythium myriotylum were quantified and tested for their in vitro fungitoxicity on the causal agent of the cocoyam root rot disease. All clones, infected or not, have phenolic compounds showing fungitoxic activity. The phenolic content of the tolerant and susceptible clones is less than that observed in the resistant one meanwhile in the resistant clone RO1075, a large increase in phenolic content is observed particularly in the roots during attack by pathogen.
Defense responses induced by soluble silicon in cucumber roots infected by Pythium spp.
The role of silicon (Si) in plant growth was investigated on the basis of induction of defense mechanisms in response to fungal attacks. Amendment of cucumber plants with soluble Si (Si+) resulted in a marked stimulation of chitinase activity and in a more intense and rapid activation of peroxidases and polyphenoloxidases after infection with Pythium spp. Additionally, glycosidically bound phenolics extracted from Si+ plants and subjected to acid or β-glucosidase hydrolysis (Gly extracts) displayed a strong fungistatic activity against P. ultimum, P. aphanidermatum, and Cladosporium cucumerinum. Extracts obtained in the same way from control plants were not inhibitory to fungal growth, regardless of Si treatment [...]
Impact of acetaldehyde‐ and pyruvic acid‐bound sulphur dioxide on wine lactic acid bacteria
Aims:  To investigate the impact of acetaldehyde‐ and pyruvic acid‐bound sulphur dioxide on wine lactic acid bacteria (LAB).