Li Qiang, Dou Wanfu, Qi Jingjing, Qin Xiujuan, Chen Shanchun, He Yongrui
Citrus Research Institute, Southwest University/Chinese Academy of Agricultural Sciences, Chongqing 400712, People's Republic of China.
J Genet. 2020;99.
Class III peroxidase (CIII prx) is a plant-specific multigene family that regulates the physiological and stress responses. This research aimed to exhaustively annotate and analyse the CIII prx family in sweet orange and to explore the regulated expression profiles by subsp. () and plant hormones. We further assessed the relationship between CIII prxs and citrus bacterial canker. The phylogeny, gene structure, conserved motifs, gene duplications and microsynteny of the CIII prx family were analysed. Expression profiles of specific CsPrxs induced by subsp. and plant hormones were detected by quantitative reverse transcription-polymerase chain reaction. Subcellular localization was analysed through transient expression assessments. A total of 72 CIII prx members were identified from the genomes of sweet orange. In all chromosomes of sweet orange, the CsPrxs could be detected except in chromosome 8. In addition, three segmental duplications, four tandem duplications and 11 whole-genome duplications occurred among the CsPrxs, contributing to the family size expansion. From the / ratios, 15 of 18 duplicated CsPrxs pairs have experienced purifying selection process. A total of 15 conserved motifs were detected in CsPrxs, four of which were detected in all complete CsPrxs. A total of 12 expressed genes were identified from the EST database. The expression trends of 12 CsPrxs were differently expressed at different stages of infection by , five of which were potential candidate genes involved in resistance. These genes could be induced by salicylic acidand methyl jasmonate, and were extracellular proteins. These results further support our understanding of CIII prxs in citrus, particularly incitrus bacterial canker studies.
Ⅲ类过氧化物酶（CIII prx）是一个植物特有的多基因家族，可调节生理和应激反应。本研究旨在全面注释和分析甜橙中的CIII prx家族，并探索其受 亚种（）和植物激素调控的表达谱。我们还进一步评估了CIII prxs与柑橘溃疡病之间的关系。分析了CIII prx家族的系统发育、基因结构、保守基序、基因重复和微共线性。通过定量逆转录-聚合酶链反应检测了由 亚种和植物激素诱导的特定CsPrxs的表达谱。通过瞬时表达评估分析亚细胞定位。从甜橙基因组中鉴定出总共72个CIII prx成员。在甜橙的所有染色体中，除了8号染色体外，均可检测到CsPrxs。此外，CsPrxs之间发生了3次片段重复、4次串联重复和11次全基因组重复，导致了该家族规模的扩大。从 / 比率来看，18对重复的CsPrxs中有15对经历了纯化选择过程。在CsPrxs中总共检测到15个保守基序，其中4个在所有完整的CsPrxs中均有检测到。从EST数据库中鉴定出总共12个表达基因。在 感染的不同阶段，12个CsPrxs的表达趋势存在差异，其中5个是参与 抗性的潜在候选基因。这些基因可被水杨酸和茉莉酸甲酯诱导，并且是细胞外蛋白。这些结果进一步支持了我们对柑橘中CIII prxs的理解，特别是在柑橘溃疡病研究方面。
