The multifaceted role of YSL proteins: Iron transport and emerging functions in plant metal homeostasis

Abstract

Understanding metal transport in plants has always been critical. Several gene families have been identified in the last two decades that have aided in the understanding of channelized metal transport, including their uptake, distribution, and storage in plants. Identifying Yellow Stripe-like (YSL) genes has contributed to an improved understanding of metal homeostasis in plants, especially monocots. Several studies have demonstrated that these genes play a role in transporting metals complexed with phytosiderophores (PS) and/or nicotianamine (NA). In the current review, we have discussed and opinionated the signalling role of YSL protein in maintaining inter and intracellular metal homeostasis in plants. Although the genes are known to have a broader range of metal substrate specificity, these are primary iron (Fe) transporters, and a detailed Fe transport in plants is discussed. Furthermore, based on recent findings, alternative functions of these genes are also discussed. Overall, we provide a broader overview of YSL protein in modulating the Fe mobilization and provides evidence of the expanding functions in plants.