Some benefits of silicon (Si) fertilization have been reported in sugarcane plants, but information about the effects of Si on brown rust (Puccinia melanocephala) remain scarce, even though this plant disease is widespread in several areas around the world. The objective of this study was to evaluate whether Si potentiates the production of antimicrobial metabolites in sugarcane plants in response to infection by P. melanocephala. Experiments with a sugarcane cultivar (SP70–1143) susceptible to brown rust were conducted in pots (3 L) under greenhouse conditions using a randomized complete block design with four treatments: with and without Si (equivalent to 0 and 800 kg ha⁻¹ of Si, denominated -Si and + Si, respectively), sprayed with water or inoculated with a suspension of P. melanocephala urediniospores. Liquid potassium silicate was applied in soil as a source of Si. Si fertilization increased soil Si and Si concentration in plants, which correspondingly decreased brown rust severity and sporulation of P. melanocephala in leaves. Silicon fertilization increased the concentration of sucrose and cis-aconitic acid and reduced the concentration of chlorogenic acid (trans-3-caffeoylquinic acid) in sugarcane leaves inoculated with the pathogen. In vitro germination of P. melanocephala was reduced in contact with all metabolites isolated by UHPLC-DAD (chlorogenic acid and C-glycosylated flavones) from the sugarcane leaves. This work helps to elucidate the potential prophylactic role of Si in the interaction between P. melanocephala and sugarcane.

甘蔗植物中已经报道了硅肥施用的一些好处，但是关于硅对棕锈病（Puccinia melanocephala）的影响的信息仍然很少，尽管这种植物病在世界各地都有广泛的传播。这项研究的目的是评估Si是否增强了甘蔗植物对黑头。的感染产生的抗菌代谢产物。在温室条件下，在盆（3 L）中采用随机完整块设计，对甘蔗品种（SP70–1143）进行了棕锈试验，该随机完整块设计采用以下四种处理方法：有和没有硅（分别为0和800 kg ha ^-1分别喷洒水或接种黑头病原虫孢子的悬浮液。液态硅酸钾被用作土壤中的硅源。施硅增加了土壤中硅和硅的含量，从而相应地降低了棕锈病严重程度和叶片黑头病菌的孢子形成。硅肥增加了接种病原体的甘蔗叶中蔗糖和顺式乌头酸的浓度，并降低了绿原酸（反式-3-咖啡酰奎尼酸）的浓度。体外萌发P. melanocephala与由UHPLC-DAD分离所有代谢接触（绿原酸还原并C-糖基化的黄酮）。这项工作有助于阐明潜在的预防作用的硅黑头和甘蔗之间的相互作用中的硅。