Interactive Role of Silicon on Attenuating Aluminum Toxicity in Sugarcane by Modifying Growth, Root Morphoanatomy, Photosynthetic Pigments, and Gas Exchange Parameters

Abstract

Abstract Aluminum (Al) inhibits growth and limits plant productivity in acidic soils. An important strategy to increase Al tolerance is the use of silicon (Si) nutrition. Thus, the aim of this study was to investigate the interactive function of Si supplementation on the biological responses of sugarcane s (Saccharum officinarum L., cultivars 'CTC9002' and 'CTC9003') under Al toxicity. Two pots experiments with four replications were conducted as a factorial scheme (2 × 4), in a completely randomized design to study the impact of Si (2 mM) on attenuating Al toxicity (0, 10, 15 e 20 mg L−1, as Al2(SO4)3·18H2O) in sugarcane seedlings. After 35 days, Al stress decreased sugarcane growth and the Si uptake capacity by decreasing the root growth and increasing Al uptake and translocation. Si attenuated Al toxicity in the sugarcane seedlings by limiting Al uptake and transport to the shoots, caused positive changes in roots morphoanatomy, higher content pigments, improving gas exchange parameters, thereby increased growth. The attenuation of Al toxicity by Si is more evident in the cultivar CTC9003. The findings of this study suggest that Si plays a notable role in improving anatomical and physiological aspects, in particular the growth of sugarcane seedlings under Al toxicity.