Elicitor-Induced Defense Responses inSolanum lycopersicumagainstRalstonia solanacearum

Abstract

We investigated on important parameters of induced resistance in hydroponic tomato (Solanum lycopersicum) against Ralstonia solanacearum using the elicitors chitosan (CHT), salicylic acid (SA), and jasmonic acid (JA). The increase in total phenolic content of roots by the elicitors was significantly higher than control. Most pronounced increase in lignin synthesis was triggered by SA followed by CHT. At 24 h post-elicitation (hpe), the activity of phenylalanine ammonia lyase was 4.5 times higher than control elicited by CHT. The peroxidase activity was about 86 nkat/mg protein at 24 hpe in case of SA and 78 nkat/mg protein in case of CHT. The activity of polyphenol oxidase increased several folds by the elicitors. Cinnamyl alcohol dehydrogenase activity increased to the maximum at 48 hpe under the influence of CHT. The results indicate that the elicitors SA and CHT induced effective defense responses in tomato plants against R. solanacearum. This was evident from reduced vascular browning and wilting symptoms of tomato plants treated with SA and CHT and challenged subsequently with R. solanacearum. This reduced disease incidence in tomato by SA and CHT may be a result of cell wall strengthening through deposition of lignin and the coincident induction of defense enzymes.

Effect of temperature and resistance of tobacco cultivars to the progression of bacterial wilt, caused by Ralstonia solanacearum

“…It is possible that low temperature triggers the production of such proteins and thus indirectly influences the expression of resistance. Another explanation may be that different temperatures may interfere with the expression of chitosan, and salicylic acid found to induce defense responses in plants against R. solanacearum (Mandal et al 2013). Tobacco, a plant with known genomic sequence (Sierro et al 2014), can provide a valuable background host to investigate interactions with R. solanacearum.…”

Plant Resistance Inducers against Pathogens in Solanaceae Species—From Molecular Mechanisms to Field Application

“…SA induces SAR in pepper [41], and gives protection against R. solanacearum in tomato [48]. In vitro potato cultures supplemented with SA have been shown to be more resistant against Dickeya solani [70], and IAA has been found to be effective against Fusarium oxysporum in tomato [42].…”

“…This PRI is produced by deacetylation of chitin from crustaceans. Chitosan improved resistance against R. solanacearum , F. oxysporum and P. capsici in tomato [47,48,107]. In pepper and tomato it induces SAR and stress-related pathways [41,47].…”

Induction of Resistance Mediated by an Attenuated Strain ofValsa malivar.maliUsing Pathogen-Apple Callus Interaction System

“…The increase in the absorbance at 405 nm was measured [28]. CAT activity was reflected by the reduction in the amount of H 2 O 2 according to the method of Cakmak and Marschner [29].…”