The AP2/ERF gene family is one of the most conserved and important transcription factor families mainly occurring in plants with various functions in regulating plant biological and physiological processes. However, little comprehensive research has been conducted on the AP2/ERF gene family in Rhododendron (specifically, Rhododendron simsii), an important ornamental plant. The existing whole-genome sequence of Rhododendron provided data to investigate the AP2/ERF genes in Rhododendron on a genome-wide scale. A total of 120 Rhododendron AP2/ERF genes were identified. The phylogenetic analysis showed that RsAP2 genes were classified into five main subfamilies, AP2, ERF, DREB, RAV and soloist. Cis-acting elements involving plant growth regulators, response to abiotic stress and MYB binding sites were detected in the upstream sequences of RsAP2 genes. A heatmap of RsAP2 gene expression levels showed that these genes had different expression patterns in the five developmental stages of Rhododendron flowers. Twenty RsAP2 genes were selected for quantitative RT-PCR experiments to clarify the expression level changes under cold, salt and drought stress treatments, and the results showed that most of the RsAP2 genes responded to these abiotic stresses. This study generated comprehensive information on the RsAP2 gene family and provides a theoretical basis for future genetic improvement.

中文翻译：

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杜鹃花 AP2/ERF 基因家族的全基因组分析：响应寒冷、盐分和干旱胁迫的鉴定和表达谱。

AP2/ERF基因家族是最保守和最重要的转录因子家族之一，主要存在于植物中，具有调节植物生物学和生理过程的多种功能。然而，对重要观赏植物杜鹃花（具体而言，杜鹃花）的AP2/ERF基因家族的综合研究却很少。现有的杜鹃花全基因组序列为在全基因组范围内研究杜鹃花中的 AP2/ERF 基因提供了数据。共鉴定出 120 个杜鹃花 AP2/ERF 基因。系统发育分析表明，RsAP2基因分为五个主要亚家族，AP2、ERF、DREB、RAV和soloist。在 RsAP2 基因的上游序列中检测到涉及植物生长调节剂、非生物胁迫响应和 MYB 结合位点的顺式作用元件。RsAP2 基因表达水平的热图表明，这些基因在杜鹃花的五个发育阶段具有不同的表达模式。选择20个RsAP2基因进行定量RT-PCR实验，阐明冷、盐和干旱胁迫处理下表达水平的变化，结果表明大部分RsAP2基因对这些非生物胁迫有反应。该研究获得了关于RsAP2基因家族的全面信息，为未来的遗传改良提供了理论基础。结果表明，大多数 RsAP2 基因都对这些非生物胁迫做出了反应。该研究获得了关于RsAP2基因家族的全面信息，为未来的遗传改良提供了理论基础。结果表明，大多数 RsAP2 基因都对这些非生物胁迫做出了反应。该研究获得了关于RsAP2基因家族的全面信息，为未来的遗传改良提供了理论基础。