Sugarcane aphid (Melanaphis sacchari) is a phloem-feeding insect that severely affects the growth and productivity of sorghum and other related crops. While a growing body of knowledge is accumulating regarding plant, and insect interactions, the role of reactive oxygen species (ROS) against aphid infestation in sorghum has not been established yet. Here, the involvement of H2O2 and ROS detoxification enzymes in host plant resistance to sugarcane aphid in sorghum was demonstrated. The H2O2 accumulation and expression patterns of selected ROS scavenging enzymes including ascorbate peroxidase (APX), glutathione S transferase (GST), superoxide dismutase (SOD), and catalase (CAT) in response to sugarcane aphid infestation at 3, 6, 9, and 12 days post infestation (dpi) in resistant (Tx2783) and susceptible (Tx7000) sorghum genotypes were assessed, respectively. A significant increase in H2O2 accumulation was observed in resistant genotypes at all time points studied as compared to susceptible plants. Furthermore, gene expression analysis revealed that in responding to attack by sugarcane aphid, antioxidant genes were induced in both genotypes, but much stronger in the resistant line. Furthermore, aphid survival and fecundity were significantly inhibited in resistant plants compared to susceptible plants. Taken together, our results suggest that the elevated accumulation of H2O2 and the strong upregulation of the antioxidant genes in sorghum may have contributed to host plant resistance in Tx2783 against sugarcane aphid but the weak expression of those antioxidant genes in Tx7000 resulted in the failure of attempting defense against sugarcane aphid. This report also provides the experimental evidence for the role of ROS involvement in the early defensive response to an attack by sugarcane aphid in sorghum.

中文翻译：

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活性氧产生的增加与高粱中宿主植物对甘蔗蚜虫的抗性有关。

甘蔗蚜虫（Melanaphis sacchari）是一种以韧皮部为食的昆虫，严重影响高粱和其他相关作物的生长和生产力。虽然关于植物和昆虫相互作用的知识不断积累，但活性氧（ROS）对抗高粱蚜虫侵染的作用尚未确定。在这里，H2O2 和 ROS 解毒酶参与了高粱宿主植物对甘蔗蚜虫的抗性。选定的 ROS 清除酶（包括抗坏血酸过氧化物酶 (APX)、谷胱甘肽 S 转移酶 (GST)、超氧化物歧化酶 (SOD) 和过氧化氢酶 (CAT)）在 3、6、9 和 3 小时响应甘蔗蚜虫侵染的 H2O2 积累和表达模式分别评估抗性(Tx2783)和易感(Tx7000)高粱基因型感染后12天(dpi)。与易感植物相比，在所有研究时间点的抗性基因型中都观察到 H2O2 积累显着增加。此外，基因表达分析表明，在应对甘蔗蚜虫攻击时，两种基因型中的抗氧化基因均被诱导，但在抗性品系中更强。此外，与易感植物相比，抗性植物中的蚜虫存活和繁殖力受到显着抑制。综上所述，我们的结果表明，高粱中 H2O2 积累的增加和抗氧化基因的强烈上调可能导致了 Tx2783 中宿主植物对甘蔗蚜虫的抗性，但 Tx7000 中这些抗氧化基因的弱表达导致了尝试的失败。防御甘蔗蚜虫。该报告还为ROS参与高粱对甘蔗蚜虫攻击的早期防御反应中的作用提供了实验证据。