Abstract: Class Ⅲ peroxidases in plants, as the unique secretory peroxidases, are widely exist in extracellular space or vacuole, and participate in developmental and biochemical pathways in response to biotic and abiotic stresses. To analyse their functions in cotton fiber development, we searched Class Ⅲ peroxidases in Gossypium raimondii genome using GO Annotation and Conserved Domain Analysis. The results showed that G. raimondii genome contains 90 peroxidase genes, which can be classified into 8 subgroups. Transcriptome analysis revealed that the Class Ⅲ GrPrx genes have differential expression patterns in different tissues and different fiber developmental stages, in which GrPrx11 and GrPrx16 highly express in the secondary cell wall synthesis stage, indicating that the importance of Class Ⅲ GrPrxs genes during fiber development.

Key words: cotton fiber development, Class Ⅲ peroxidases, gene structure, gene expression

摘要： 第Ⅲ类过氧化物酶（Class Ⅲ Peroxidases，Prxs）是植物特有的过氧化物酶家族，存在于植物细胞外空间或液泡中，参与了植物抗逆和生长发育等多个过程。为了分析过氧化物酶基因在棉花纤维发育过程中的功能，利用蛋白保守结构域分析方法，对雷蒙德棉（D组）第Ⅲ类过氧化物酶家族基因进行了全基因组鉴定，确定了90个第Ⅲ类过氧化物酶基因。进一步根据聚类分析、基因结构分析和蛋白亚细胞定位分析结果将雷蒙德棉第Ⅲ类过氧化物酶划分成8个亚类。最后，结合转录组数据和qRT-PCR对基因的表达模式进行了分析，获得了在棉花纤维不同发育阶段高水平表达的候选基因GrPrx11和GrPrx3、GrPrx21和GrPrx77。这些特异性高表达基因的鉴定为深入研究过氧化物酶基因在纤维发育中的功能奠定了一定的基础。

关键词: 棉花纤维发育, 第Ⅲ类过氧化物酶, 基因结构分析, 基因表达分析