The mechanisms of the symplastic Manganese toxicity in rice plants

the inhibition of photosynthesis through the disruption of auxin homeostasis in leaves

Abstract

Manganese (Mn) is one of the essential mineral nutrients for land plants, and Mn is involved in various physiological reactions as an activator or cofactor of certain enzymes in plant cells. In crop plants, it is well known that Mn deficiency decreases the crop yield by attenuating photosynthetic activity, especially in oxygen-evolving activity in photosystem II. On the other hand, the excess Mn fertilization also suppresses the photosynthetic activities in crop plants to reduce their yield. However, the detailed molecular mechanisms to suppress photosynthetic activities under excess Mn fertilization is remained to be clarified. In this review, we introduce the mechanisms of how excess Mn suppresses photosynthetic activity in land plants based on our recent research using rice plants.