Chitosan nanoparticles: A positive modulator of innate immune responses in plants

• Published in: Scientific reports Vol. 5; no. 1; p. 15195
• Main Authors: Chandra, Swarnendu, Chakraborty, Nilanjan, Dasgupta, Adhiraj, Sarkar, Joy, Panda, Koustubh, Acharya, Krishnendu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 16.10.2015; Nature Publishing Group
• Subjects: 38/77; 631/449/2675; 639/925/357/354; 96/34; 96/63; Antimicrobial agents; Biopolymers; Camellia sinensis - genetics; Camellia sinensis - immunology; Camellia sinensis - metabolism; Chitosan - chemistry; Chitosan - metabolism; Chromatography, High Pressure Liquid; Disease control; Enzymes; Flavonoids; Flavonoids - analysis; Fluorescein-5-isothiocyanate; Humanities and Social Sciences; Immune response; Immunity, Innate - drug effects; Immunology; Innate immunity; Microscopy, Fluorescence; multidisciplinary; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - metabolism; Nanoparticles - toxicity; Nitric Oxide - metabolism; Oxidoreductases - genetics; Oxidoreductases - metabolism; Pathogens; Phenols; Phenols - analysis; Plant diseases; Plant Leaves - genetics; Plant Leaves - immunology; Plant Leaves - metabolism; Plants - genetics; Plants - immunology; Plants - metabolism; Real-Time Polymerase Chain Reaction; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep15195

The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant’s innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.