Silicon induces resistance to leaf scald in sugarcane under water deficit

Abstract

Abstract Sugarcane is one of the main crops in the world, representing great importance for the Brazilian economy. However, phytosanitary problems mean that its production has been stagnant since 2010. Leaf scald, a disease caused by the bacteria Xanthomonas albilineans, affects sugarcane fields, reducing their productivity, with its effects intensified by water deficiency. Currently, there are no treatments to control this bacteriosis, making it essential to develop new strategies to reduce its damage. Thus, the use of silicon (Si) presents encouraging results in mitigating the effects caused by different stresses in different crops. However, little is known about the role of Si as an inducer of leaf scald resistance. Thus, the present work aimed to evaluate the efficiency of Si application in controlling sugarcane scald associated with water deficiency. Two sugarcane cultivars were used, one susceptible (SP78-4467) and one resistant to the disease (SP80-3280), subjected to two stresses (X. albilineans and water deficiency) and pre-treated with Si. Analysis of lipid proxidation and antioxidant enzymes (SOD, APX, GR, GPOX and GSH-Px) were analyzed. In the susceptible cultivar pre-treated with Si in the combination of stresses, the MDA content decreased. The activity of most enzymes increased in the presence of Si. Demonstrating that the exogenous application of Si acts in inducing the defense system of sugarcane plants against the effects of stress caused by the bacteria X. albilineanse and water deficiency, being more efficient in the responses observed for the susceptible cultivar.