Rhizobium-Mediated Induction of Phenolics and Plant Growth Promotion in Rice (Oryza sativa L.)

Abstract

Qualitative and quantitative estimation of phenolic compounds was done through reverse phase-high performance liquid chromatography (RP-HPLC) from different parts (leaf, stem, and root) of rice plants after inoculation with two rhizobial strains, RRE6 (Rhizobium leguminosarum bv. phaseoli) and ANU 843 (R. leguminosarum bv. trifolii) and infection by Rhizoctonia solani. On the basis of their retention time, the major phenolic acids detected in HPLC analysis were gallic, tannic, ferulic, and cinnamic acids. Furthermore, in all Rhizobium-inoculated rice plants, synthesis of phenolic compounds was more consistently enhanced than in control (uninoculated plants), where the maximum accumulation of phenolic compounds was observed in plants inoculated with RRE6 and infection with R. solani. Under pathogenic stress, RRE6 performed better because a relatively higher amount of phenolics was induced as compared with plants treated with ANU 843. Phenolic acids mediate induced systemic resistance and provide bioprotection to plants during pathogenic stresses. In addition, both rhizobial strains promote growth and productivity of rice plants in greenhouse conditions. This report on Rhizobium-mediated defense responses and growth promotion of nonlegume (such as rice) provides a novel paradigm of symbiotic plant-microbe interaction.

Promoção de crescimento de arroz por rizóbios em diferentes níveis de adubação nitrogenada

“…Assim, plantas com maior produção de panículas têm maior rendimento de grão. Em um estudo feito na Índia, o número de panículas de arroz aumentou em média 23,3%, quando as plantas foram inoculadas com estirpes de rizóbios (MISHRA et al, 2006).…”

“…Por outro lado, o estímulo dos isolados UFRGS-Lc336 e UFRGS 1-TV na absorção de N foi mais pronunciado em doses elevadas de N. Com a dose de 160kg ha -1 de N, o acúmulo de N na parte aérea das plantas inoculadas com estes dois isolados foi 29% superior ao das plantas do tratamento controle e sem inoculação. Este incremento é muito próximo Tabela 3 -Número de perfilhos por planta de arroz, cultivar 'IRGA 424', em função da inoculação com isolados de rizóbios e aplicação de doses crescentes de N. (BISWAS et al, 2000;YANNI et al, 2001;CHI et al, 2005;MISHRA et al, 2006). Embora o efeito da promoção de crescimento tenha aumentado com o acréscimo da dose de N, os resultados também indicaram que a inoculação de rizóbios proporcionou melhor aproveitamento do N aplicado, pois aumentou o acúmulo deste elemento e proporcionou maior eficiência na adubação.…”

“…II (PERRINE-WALKER et al, 2007;YANNI & DAZZO, 2010;OSORIO FILHO et al, 2014;HAHN et al, 2014). Vivendo endofiticamente, os rizóbios podem estimular o crescimento das plantas, devido à produção de substâncias hormonais, principalmente auxinas (BISWAS et al, 2000), a solubilização de fosfatos (RODRIGUEZ & FRAGA, 1999) e a proteção das plantas contra patógenos (MISHRA et al, 2006).…”

Comparative Analysis of Phenolic Content and Anti-oxidant Activity of Dietary Vegetables

“…Recently (Patricia et al, 2008) and (Ravi et al, 2006) Similarly the molecular anti-oxidant response of phenolics in methyl linoleate varies remarkably depending on their chemical structure (Anna et al, 2008). Thus the anti-oxidant activity of an extract could not be explained just on the basis of their phenolic content but also required their proper characterization.…”

Identification and determination of characteristics of endophytes from rice plants and their role in biocontrol of bacterial blight caused by Xanthomonas oryzae pv. oryzae

“…KJ006, for example, was used against Burkholderia glumae and Rhizobium leguminosarum bv. phaseoli against Rhizoctonia solani (Mishra et al, 2006). Similarly, other endophytic bacteria have been used to protect rice cultivars from major fungal infections including Penibacillus spp., Microbacterium spp., Bacillus spp.…”