Guangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research, Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural Affairs, Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
Int J Mol Sci. 2024 May 26;25(11):5804. doi: 10.3390/ijms25115804.
Class III peroxidases (CIII PRXs) are plant-specific enzymes with high activity that play key roles in the catalysis of oxidation-reduction reactions. In plants, CIII PRXs can reduce hydrogen peroxide to catalyze oxidation-reduction reactions, thereby affecting plant growth, development, and stress responses. To date, no systematic analysis of the CIII PRX gene family in litchi ( Sonn.) has been documented, although the genome has been reported. In this study, a total of 77 CIII PRX (designated LcPRX) gene family members were predicted in the litchi genome to provide a reference for candidate genes in the responses to abiotic stresses during litchi growth and development. All of these genes had different numbers of highly conserved PRX domains and were unevenly distributed across fifteen chromosomes. They were further clustered into eight clades using a phylogenetic tree, and almost every clade had its own unique gene structure and motif distribution. Collinearity analysis confirmed that there were eleven pairs of duplicate genes among the LcPRX members, and segmental duplication (SD) was the main driving force behind the gene expansion. Tissue-specific expression profiles indicated that the expression levels of all the LcPRX family members in different tissues of the litchi tree were significantly divergent. After different abiotic stress treatments, quantitative real-time PCR (qRT-PCR) analysis revealed that the genes responded to various stresses and displayed differential expression patterns. Physicochemical properties, transmembrane domains, subcellular localization, secondary structures, and cis-acting elements were also analyzed. These findings provide insights into the characteristics of the LcPRX gene family and give valuable information for further elucidating its molecular function and then enhancing abiotic stress tolerance in litchi through molecular breeding.
III 类过氧化物酶（CIII PRXs）是植物特有的具有高活性的酶，在氧化还原反应的催化中起着关键作用。在植物中，CIII PRX 可以将过氧化氢还原以催化氧化还原反应，从而影响植物的生长、发育和应激反应。迄今为止，尽管已经报道了荔枝（Litchi chinensis Sonn.）的基因组，但尚未对 CIII PRX 基因家族进行系统分析。在本研究中，共预测了荔枝基因组中的 77 个 CIII PRX（命名为 LcPRX）基因家族成员，为荔枝生长发育过程中应对非生物胁迫的候选基因提供了参考。这些基因都具有不同数量的高度保守的 PRX 结构域，并且在十五条染色体上不均匀分布。它们进一步使用系统发育树聚类为八个分支，几乎每个分支都有其独特的基因结构和基序分布。共线性分析证实，LcPRX 成员中有 11 对重复基因，片段复制（SD）是基因扩展的主要驱动力。组织特异性表达谱表明，荔枝树不同组织中所有 LcPRX 家族成员的表达水平存在显著差异。经过不同非生物胁迫处理后，定量实时 PCR（qRT-PCR）分析表明，LcPRX 基因响应各种胁迫并表现出不同的表达模式。还分析了理化性质、跨膜结构域、亚细胞定位、二级结构和顺式作用元件。这些发现深入了解了 LcPRX 基因家族的特征，并为进一步阐明其分子功能提供了有价值的信息，然后通过分子育种提高荔枝的非生物胁迫耐受性。
