Chitosan physico–chemical properties modulate defense responses and resistance in tobacco plants against the oomycete Phytophthora nicotianae

Chitosans of different molecular weight enhance potato (Solanum tuberosum L.) yield in a field trial

“…pathogen inhibition (Xu et al, 2007;Hernández-Lauzardo et al, 2008;Badawy & Rabea, 2011;Falcón-Rodríguez et al, 2012) and eliciting plant defence responses (Cabrera et al, 2006;Trotel-Aziz et al, 2006;Falcón-Rodríguez et al, 2011). However, there are not reports regarding the influence of MW on plant growth and yield enhancing under field conditions.…”

Exploiting Plant Innate Immunity to Protect Crops Against Biotic Stress: Chitosaccharides as Natural and Suitable Candidates for this Purpose

“…Depending on dose and type of chitosan tested, it was observed increments of 2-3 times above the control for β 1-3 glucanase activity, while for PAL ranged between 2 and 10 times and for peroxidase ranged between 4 and 10 times. Ulterior infection assays performed against Phytophthora nicotianae showed a significant relation between the plant protections achieved and the PAL and β 1-3 glucanase activities detected (Falcón et al, 2011).…”

“…The best efficiency with lower MW chitosans on the activation of induced resistance in whole plants was corroborated in tobacco treated by foliar spray. β-1,3-glucanase activity in tobacco leaves required 10 times higher polymer concentration than oligochitosan mixture to induce the highest activity detected above control and this enzyme was significant related to the plant protection found against the infection with Phytophthora nicotianae (Falcón et al, 2011).…”

“…Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) enzymatic activity and its gene expression is likely one of the defense proteins more studied in response to these elicitors, since it is a key enzyme in the phenylpropanoid pathway and it is also involved in the synthesis of salicylic acid a key signal in plant resistance against pathogens (Way et al, 2002;Ogawa et al, 2006 (Falcón et al, 2008) and oligochitosans (Khan et al, 2003) in a variety of plant systems as cell suspensions (Lin et al, 2005;Cabrera et al, 2006;, plant organs elicited (Vander et al, 1998;Trotel-Aziz et al, 2006) and roots and leaves of whole plants (Mandal & Mitra, 2007;Falcón et al, 2009;2011). In several reports the role of PAL induced by chitosaccharides as cardinal protecting factor against pathogens has been stated in different plant-pathogen systems Yafei et al, 2009;Falcón et al, 2011).…”

“…Moreover, when using a foliar spray of whole plants the best results detected in rice leaves for this enzyme activity required 500 mg.L -1 of chitosan hydrolysate elicitor (Rodríguez et al, 2007) and 1000 mg.L -1 of the DP 5-9 oligochitosan mixture in tobacco leaves (Falcón et al, 2011). β 1-3 glucanase (EC 3.2.1.39) and chitinase (EC 3.2.1.14) catalyze the degradation of β 1-3 glucan and chitin polymers, majors cell wall components of many pathogens (Arlorio et al, 1992).…”