Processes and mechanisms of photosynthesis augmented by engineered nanomaterials

With their unique physicochemical properties, engineered nanomaterials (NMs) have been suggested to be regulators of the physiological and biochemical processes in terrestrial plants. Engineered nanoparticles (NPs) can be absorbed and stored in plant tissues, which lead to beneficial effects on their photosynthetic performance. However, to date, there has not been a comprehensive overview on the processes and underlying mechanisms of augmented photosynthesis by NMs. For this review, we examine enhanced plant photosynthesis by NMs through both light and dark reactions, and we herein discuss the potential mechanisms involved. Precautions are also presented for applying NMs in agriculture. A foliar spray of NMs is able to improve the photosynthetic efficiency better than their application to soil. In addition, coatings with negative charges and greater biocompatibility are able to facilitate the uptake of NMs by plants. As a foundational and pivotal physiological process, the promoted photosynthesis induced by NMs will likely increase crop yields and potentially further benefit sustainable agriculture. Hence, the underlying mechanisms of NM-enhanced photosynthetic efficiency need to be better understood to increase crop productivity and to minimise the environmental impact when applying agricultural nanotechnology.