Induction of defense response of Oryza sativa L. against Pyricularia grisea (Cooke) Sacc. by treating seeds with chitosan and hydrolyzed chitosan

Cellulase Applied to the Leaves of Sweet Pepper (Capsicum annuumL. var.grossum) Upregulates the Production of Salicylic and Azelaic Acids

“…12) Although it was found that a cellulase treatment of pepper (C. annuum L.) induced phytoalexin biosynthesis, the endogenous amounts of SA (1), Phe (2) and AzA (3) and the induced ability to withstand pathogenic attack were not discussed. Other kinds of agents such as chitosan 13,14) have been utilized as elicitors to induce the plant defense system. In this respect, it would be very interesting to evaluate the endogenous amounts of SA (1) Phe (2) and AzA (3) after treating with such agents.…”

Eficiência de diferentes moléculas na redução dos sintomas da queima das bainhas em arroz e no crescimento de Rhizoctonia solani in vitro

“…Sabe-se que o grau de polimerização, o nível de desacetilização e a distribuição das cargas no polímero afetam a atividade biológica da quitosana (Muzzarelli, 1996). Em arroz, o pré-tratamento de sementes e a pulverização das plantas com quitosana e quitosana hidrolisada, nas concentrações de 100 a 1000 mg/L, reduziu a severidade da brusone (Rodríguez et al, 2007). De acordo com Lin et al (2005), quanto menor o peso molecular da quitosana pulverizada nas plantas de arroz, maior foi a redução na severidade da brusone.…”

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

“…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).…”

“…Chitosaccharides also induce these PR proteins in inoculated and non inoculated monocots and dicots plants, and in different plant biological systems (Table 2). Rodríguez and coworkers evaluated in separate trials the induction PAL, β 1-3 glucanase, chitinase and chitosanase in leaves of rice plants previously treated, by seed immersion before planting, with a chitosan polymer and with a hydrolysate obtained from the same chitosan polymer in non inoculated plants (Rodríguez et al, 2004; and also in inoculated (Pyricularia grisea) plants (Rodríguez et al, 2007). It was observed significant increments above the control in all enzymes tested in leaves of non inoculated plants at 18, 25, 32 and 39 days after seed germination (Rodríguez et al, 2004;.…”

“…It means that chitosan seeds immersion can cause high increments of defense responses in non inoculated plants several weeks after treatment. In a different trial, the same authors comparatively evaluated the eliciting of the above studied enzymes in P. grisea inoculated rice plants and monitoring enzymatic activities at 1, 3, 5 and 7 days after inoculation (Rodríguez et al, 2007). As in the former reports, the chitosan polymer caused 2-3 times increments above control activity in the four enzymes tested and similar results were found with the hydrolysate in all the enzymes, except for PAL activity that increased 3-4 times above the level of control at 72 hours with all three concentrations tested.…”