Are Aquaporins (AQPs) the Gateway that Conduits Nutrients, Persistent Organic Pollutants and Perfluoroalkyl Substances (PFASs) into Plants?

Abstract

Besides water and sunlight, plants and/or crops also require an assortment of dissimilar nutrients/elements to grow. Thus, some of these nutrients have been classified as essential or macronutrients, [e.g. calcium (Ca), magnesium (Mg) and sulphur (S)], for they facilitate plant growth; while others, such as copper (Cu), iron (Fe), zinc (Zn), etc., are considered as micronutrients. However, it is apparent now that plants are exposed to a variety of other chemical compounds, including a range of persistent organic pollutants (POPs) and perfluoroalkyl substances (PFASs), which have been found in several plants. Hence, it has been common knowledge that mechanisms, such as mass flow, diffusion, etc., facilitated by plant root systems, have allowed the translocation of these nutrients and pollutants into plants, although other researchers have argued that roots on their own cannot elucidate the dissemination of these chemical constituents into plants. This dissension remained until the discovery of aquaporins (AQPs), which ultimately led to numerous AQPs being identified in plants. Thus, the aim of this review is to present an overview on the progress made thus far in attempting to understand the possibility of these proteins (i.e. AQPs) being the gateway that conduits nutrients, POPs and PFASs into plants; however, the gathered evidence currently remains rudimentary and limited, suggesting that further research is required to elucidate plant AQPs involvement at this stage in POP transportation and storage in plants.