Importance of sorghum as staple food worldwide is unquestionable and silicon (Si) supply has decreased the foliar symptoms of anthracnose, caused by Colletotrichum sublineolum, through potentiation of defense responses and preservation of photosynthetic apparatus. This study investigated the role of Si in cytological changes as well as in the expression of genes involved in auxin metabolism (GH3.1) and in signaling pathways mediated by salicylic acid (SA) (BTHip), jasmonic acid (JA)/ethylene (ET) (LOX), and JA (Jar, AOS 1, and ACCox) by real-time polymerase chain reaction in the leaves of plants non-supplied (-Si) or supplied (+Si) with Si and non-inoculated or inoculated with C. sublineolum. Sheath cells from +Si plants were less colonized by fungal hyphae due to intense phenolics and lignin deposition and high hydrogen peroxide production. Foliar lesions for +Si plants sprayed with an ET signaling inhibitor, ET biosynthesis inhibitor, and JA biosynthesis inhibitor were bigger compared to +Si plants sprayed with water. For +Si plants sprayed with ET and JA signaling inhibitors, foliar lesions were smaller compared to -Si plants sprayed with these same compounds. Suppression of auxin biosynthesis, transporter, and signaling by specific inhibitors resulted in smaller lesions. Expressions of GH3.1, BRHip, LOX, Jar, AOS 1, and ACCox were greater for +Si plants compared to -Si plants during the infection process of C. sublineolum. This study highlighted the potential of Si to boost sorghum resistance to anthracnose through a multistep process involving hormone-signaling pathways, especially regarding auxin metabolism and homeostasis, hydrogen peroxide generation, and plant cell wall strengthening.

高粱在世界范围内作为主食的重要性是毋庸置疑的，硅 (Si) 的供应通过增强防御反应和保护光合器官减少了炭疽病的叶面症状，炭疽病是由炭疽病引起的。本研究调查了Si在细胞学变化以及参与生长素代谢( GH3.1 )和由水杨酸(SA)( BTHip )、茉莉酸(JA)/乙烯介导的信号通路中的基因表达中的作用。ET) ( LOX ) 和 JA ( Jar、AOS 1和ACCox) 通过在未提供 (-Si) 或提供 (+Si) Si且未接种或接种C. sublineolum的植物叶片中进行实时聚合酶链反应。由于强烈的酚类物质和木质素沉积以及高过氧化氢产量，来自 +Si 植物的鞘细胞较少被真菌菌丝定植。与喷洒水的 +Si 植物相比，喷洒了 ET 信号抑制剂、ET 生物合成抑制剂和 JA 生物合成抑制剂的 +Si 植物的叶病灶更大。对于喷洒 ET 和 JA 信号抑制剂的 +Si 植物，与喷洒这些相同化合物的 -Si 植物相比，叶面病变更小。特定抑制剂对生长素生物合成、转运蛋白和信号传导的抑制导致较小的病变。GH3.1的表达式，在C. sublineolum的侵染过程中，与-Si植物相比，+Si植物的BRHip、LOX、Jar、AOS 1和ACCox更大。这项研究强调了 Si 通过涉及激素信号传导途径的多步骤过程提高高粱对炭疽病的抗性的潜力，特别是在生长素代谢和体内平衡、过氧化氢生成和植物细胞壁强化方面。