Nano carriers for nitric oxide delivery and its potential applications in plant physiological process: A mini review

Nitric oxide (NO) plays a key role in plant growth and defense. Since NO is a small molecule, devoid of charge and relatively lipophilic, it easily crosses cell membranes, acting as an important signaling messenger. Recently, several papers described the beneficial effects due to application of small molecular weight NO donors in plants. Exogenous NO donors break seed dormancy, stimulate plant germination and greening, control iron homeostasis in plants, and improve plant tolerance to salinity, metal toxicity, temperature and drought stress. However, these NO donors are thermally and photochemically unstable. A promising strategy that has been successfully used in biomedical applications is the combination of NO donors with nanomaterials. The encapsulation of NO donors in nanoparticles/nanotubes is able to control the release of therapeutic amounts of NO, thus improving its beneficial effects. Although nanomaterials have been used successfully to carry agrochemicals in plants, the delivery of NO is still to be studied. In this context, the present review highlights the advantages of applications of NO donors in plants, the uses of nanotechnology in agriculture, and the necessity to develop new strategies based on the combination of NO and nanomaterials in agriculture. Therefore, this review hopes to open up new perspectives in the area of nanobiotechnology, NO and agriculture.