Knockdown of Adenosine 5'-Triphosphate-Dependent Caseinolytic Protease Proteolytic Subunit 6 Enhances Aluminum Tolerance in Peanut Plants ( L.).

Aluminum (Al) toxicity in acidic soils reduces root growth and can lead to a considerable reduction in peanut plants ( L.). The caseinolytic protease (Clp) system plays the key role in abiotic stress response. However, it is still unknown whether it is involved in peanut response to Al stress. The results from this study showed that Adenosine 5'-triphosphate (ATP)-dependent caseinolytic protease proteolytic subunit 6 (AhClpP6) in peanut plants was involved in the Al stress response through its effects on leaf photosynthesis. The expression levels in the leaf and stem significantly increased with the Al treatment times. Knockdown peanut lines accumulated significantly more Al when exposed to Al stress, which reduced leaf photosynthesis. Furthermore, in response to Al treatment, knockdown of resulted in a flattened shape of chloroplasts, disordered and flattened thylakoid, and accumulating more starch grains than those of the wild-type (WT) peanut lines. Taken together, our results suggest that regulates Al tolerance by maintaining chloroplast integrity and enhancing photosynthesis.