Nitric oxide-releasing chitosan nanoparticles alleviate the effects of salt stress in maize plants.
Nitric oxide (NO) is a signaling molecule involved in plant response to various abiotic stresses. However, the application of NO donors in agriculture is hampered by the instability of these compounds. Despite the successful uses of NO-releasing nanoparticles for biomedical purposes and the variety of nanomaterials developed as carrier systems of agrochemicals, the potential applications of nanocarriers for NO delivery in plants have not yet been tested. Herein, we report the synthesis and characterization of chitosan nanoparticles (CS NPs) containing the NO donor S-nitroso-mercaptosuccinic acid (S-nitroso-MSA). The efficiency of these NO-releasing NPs in mitigating the deleterious effects of salinity on maize plants was compared to that of the non-encapsulated NO donor. The NPs were synthesized through ionotropic gelation process, and mercaptosuccinic acid (MSA), the NO donor precursor, was encapsulated into CS NPs (91.07% encapsulation efficiency). Free thiol groups of MSA-CS NPs were nitrosated, leading to S-nitroso-MSA-CS NPs (NO-releasing NPs). The incorporation of S-nitroso-MSA into CS NPs allowed a sustained NO release. Treatments of salt-stressed maize plants with S-nitroso-MSA-CS NPs resulted in a higher leaf S-nitrosothiols content compared to that of free S-nitroso-MSA. Moreover, S-nitroso-MSA-CS NPs were more efficient than was the free NO donor in the amelioration of the deleterious effects of salinity in photosystem II activity, chlorophyll content and growth of maize plants because the protective action of the nanoencapsulated S-nitroso-MSA was achieved at lower dosages. Overall, these results demonstrate the positive impact of S-nitroso-MSA nanoencapsulation in increasing NO bioactivity in maize plants under salt stress.
Department of Animal and Plant Biology, Universidade Estadual de Londrina (UEL), Rodovia Celso Garcia Cid, km 380, CEP 86057-970, Londrina, PR, Brazil. Electronic address: halley@uel.br.
Halley C
HC
Oliveira
Department of Animal and Plant Biology, Universidade Estadual de Londrina (UEL), Rodovia Celso Garcia Cid, km 380, CEP 86057-970, Londrina, PR, Brazil.
Bruna C R
BC
Gomes
Department of Exact and Earth Sciences, Universidade Federal de São Paulo (UNIFESP), Rua São Nicolau, 210, CEP 09913-030, Diadema, SP, Brazil; Center of Natural and Human Sciences, Universidade Federal do ABC (UFABC), Av. dos Estados 5001, CEP 09210-580, Santo André, SP, Brazil.
Milena T
MT
Pelegrino
Center of Natural and Human Sciences, Universidade Federal do ABC (UFABC), Av. dos Estados 5001, CEP 09210-580, Santo André, SP, Brazil. Electronic address: amedea.seabra@ufabc.edu.br.
Amedea B
AB
Seabra
D001709:Biotechnology; D048271:Chitosan / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D009569:Nitric Oxide / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D055049:Salt Tolerance / Q000187:drug effects*; D012965:Sodium Chloride / Q000009:adverse effects*; D013870:Thiomalates / Q000737:chemistry; D003313:Zea mays / Q000187:drug effects*
D013870:Thiomalates; D009569:Nitric Oxide; D012965:Sodium Chloride; D048271:Chitosan; C046062:2-thiomalic acid
Chitosan; Nanotechnology; Nitric oxide; Polymeric nanoparticles; S-nitrosothiol; Salinity