Late embryogenesis abundant (LEA) proteins are widely involved in plant stress responsive, while their involvement in callus formation is largest unknown. In this study, we identified and conducted expression analysis of the LEA genes from Phalaenopsis equestris and Dendrobium officinale, and characterized a LEA gene from D. officinale. A total 57 and 59 LEA genes were identified in P. equestris and D. officinale, respectively. A phylogenetic analysis showed that AtM, LEA_5 and Dehydrin groups were absent in both orchids. LEA_1 group genes were strongly expressed in seeds, significantly down-regulated in flowers, and absent in vegetative organs (leaves, stems and roots) in both orchids. Moreover, LEA_1 and LEA_4 group genes from D. officinale were abundant in the protocorm-like body stage and were dramatically up-regulated in response to abscisic acid and salinity stress. A LEA_1 gene (DoLEA43) was selected for further functional analysis. DoLEA43 protein was localized in the cytoplasm and nucleus, and its promoter contained a WUN-motif that was modulated by wounding. Overexpression of DoLEA43 in Arabidopsis enhanced callus induction, causing changes to callus formation-related genes such as WIND1. Our results indicate the involvement of LEA genes in the induction of callus, which provide insights into plant regeneration.

中文翻译：

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铁皮石斛LEA基因及愈伤组织诱导基因的表征

晚期胚胎发生丰富 (LEA) 蛋白广泛参与植物应激反应，而它们在愈伤组织形成中的参与是最大的未知数。在这项研究中，我们鉴定并进行了来自蝴蝶兰和铁皮石斛的 LEA 基因的表达分析，并对来自铁皮石斛的 LEA 基因进行了表征。在 P. equestris 和 D. officinale 中分别鉴定了总共 57 和 59 个 LEA 基因。系统发育分析表明，两种兰花均不存在 AtM、LEA_5 和 Dehydrin 组。LEA_1组基因在种子中强烈表达，在花中显着下调，在两种兰花的营养器官（叶、茎和根）中均不存在。此外，LEA_1 和 LEA_4 是来自 D. officinale 在类原球茎阶段大量存在，并且在脱落酸和盐度胁迫下显着上调。选择 LEA_1 基因 (DoLEA43) 进行进一步的功能分析。DoLEA43 蛋白定位于细胞质和细胞核中，其启动子包含受创伤调节的 WUN 基序。DoLEA43 在拟南芥中的过表达增强了愈伤组织的诱导，导致与愈伤组织形成相关的基因（如 WIND1）发生变化。我们的结果表明 LEA 基因参与了愈伤组织的诱导，这为植物再生提供了见解。DoLEA43 在拟南芥中的过表达增强了愈伤组织的诱导，导致与愈伤组织形成相关的基因（如 WIND1）发生变化。我们的结果表明 LEA 基因参与了愈伤组织的诱导，这为植物再生提供了见解。DoLEA43 在拟南芥中的过表达增强了愈伤组织的诱导，导致与愈伤组织形成相关的基因（如 WIND1）发生变化。我们的结果表明 LEA 基因参与了愈伤组织的诱导，这为植物再生提供了见解。