ROS act as an signaling molecule in the biological growth and development process. The homeostasis of ROS must be kept by different antioxidant defense mechanisms. Currently, superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) as major antioxidant enzymes are not well understood in cassava (Manihot esculenta). In this research, 7 SODs, 6 CATs, and 6 APXs were identified from the cassava genome by hidden Markov models, which was supported by gene structure, protein motifs, and phylogenetic relationship analyses. SOD, CAT, and APX genes expressed differentially in different tissues of cassava, of which most SODs showed high expression levels. The comprehensive expression profiles revealed the participation of SOD, CAT, APX genes during postharvest physiological deterioration (PPD) of storage root and in response to osmotic stress and ABA as well as Xanthomonas axonopodis infection. Together, this study increases our understanding of cassava SOD, CAT, APX genes feature and their potential function during PPD process and in response to biotic and abiotic stresses in cassava, laying a solid foundation for further gene function analysis in cassava.

ROS 在生物生长和发育过程中充当信号分子。ROS 的稳态必须通过不同的抗氧化防御机制来保持。目前，木薯 ( Manihot esculenta ) 中作为主要抗氧化酶的超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT) 和抗坏血酸过氧化物酶 (APX) 尚不清楚。在这项研究中，通过基因结构、蛋白质基序和系统发育关系分析支持的隐马尔可夫模型从木薯基因组中鉴定出 7 个 SOD、6 个 CAT 和 6 个 APX。SOD、CAT和APX基因在木薯不同组织中的表达存在差异，其中大部分SODs表现出高表达水平。综合表达谱揭示了参与SOD、CAT、APX基因在贮藏根的收获后生理退化 (PPD) 期间以及对渗透胁迫和 ABA 以及轴突黄单胞菌感染的响应。总之，本研究增加了我们对木薯SOD、CAT、APX基因特征及其在 PPD 过程中以及对木薯生物和非生物胁迫响应的潜在功能的理解，为进一步分析木薯基因功能奠定了坚实的基础。