Impact of aluminum on the photosynthesis and translocation of photoassimilates

Abstract

Aluminum ion (Al³⁺) promote the root growth inhibition in acidic soils. Nevertheless, a variety of plants have a capability to grow in acidic soils by excluding and/or detoxifying the Al³⁺. By the exposure to Al³⁺, a sort of organic acids such as malate or citrate are secreted from the root tips, and the organic acids chelate Al³⁺ and detoxify. Although these organic acids are synthesized from sugars which obtained by photosynthesis, the impacts of Al³⁺ to the photosynthesis and the sugar translocation are still obscure. In the present study, we monitored the sugar translocation toward roots and photosynthetic activity in the presence of Al³⁺, and revealed that both photosynthetic activity and amount of sugars accumulated in roots are promoted. Interestingly, sugars are specifically accumulated in Al³⁺-treated roots. These results suggest that plant has a capacity to optimize their growth and development in acidic soils.