Key message

The fasciclin-like arabinogalactan proteins organization into four groups is conserved and may be related to specific roles in developmental processes across angiosperms.

Abstract

Fasciclin-like arabinogalactan proteins (FLAs) are a subclass of arabinogalactan proteins (AGPs), which contain fasciclin-like domains in addition to typical AGP domains. FLAs are present across all embryophytes, and despite their low overall sequence similarity, conserved regions that define the fasciclin functional domain (FAS) have been identified, suggesting that the cell adhesion property is also conserved. FLAs in Arabidopsis have been organized into four subgroups according to the number and distribution of functional domains. Recent studies associated FLAs with cell wall-related processes where domain organization seemed to be related to functional roles. In Arabidopsis, FLAs containing a single FAS domain were found to be important for the integrity and elasticity of the plant cell wall matrix, and FLAs with two FAS domains and two AGP domains were found to be involved in maintaining proper cell expansion under salt stress conditions. The main purpose of the present work was to elucidate the expression pattern of selected FLA genes during embryo and seed development using RT-qPCR. AtFLA8 and AtFLA10, two Arabidopsis genes that stood out in previous microarray studies of embryo development, were further examined using promoter-driven gene reporter analyses. We also studied the expression of cork oak FLA genes and found that their expression partially parallels the expression patterns of the putative AtFLA orthologs. We propose that the functional organization of FLAs is conserved and may be related to fundamental aspects of embryogenesis and seed development across angiosperms. Phylogenetic studies were performed, and we show that the same basic four-subgroup organization described for Arabidopsis FLA gene classification is valid for most Arabidopsis FLA orthologs of several plant species, namely poplar, corn and cork oak.

中文翻译：

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成束蛋白样阿拉伯半乳聚糖蛋白的计算机模拟和表达分析揭示了胚胎和种子发育过程中的功能保守性。

关键信息

成束蛋白样阿拉伯半乳聚糖蛋白组织成四组是保守的，可能与被子植物发育过程中的特定作用有关。

抽象的

类成束蛋白阿拉伯半乳聚糖蛋白 (FLA) 是阿拉伯半乳聚糖蛋白 (AGP) 的一个亚类，除了典型的 AGP 结构域外，还包含类成束蛋白结构域。FLA 存在于所有有胚植物中，尽管总体序列相似性较低，但定义了成束蛋白功能域 (FAS) 的保守区域已被识别，这表明细胞粘附特性也是保守的。拟南芥中的 FLA 根据功能域的数量和分布分为四个亚组。最近的研究将 FLA 与细胞壁相关过程联系起来，其中域组织似乎与功能角色相关。在拟南芥中，含有单个 FAS 结构域的 FLA 对植物细胞壁基质的完整性和弹性非常重要，而具有两个 FAS 结构域和两个 AGP 结构域的 FLA 被发现参与在盐胁迫条件下维持适当的细胞扩张。本工作的主要目的是利用 RT-qPCR 阐明胚胎和种子发育过程中选定的 FLA 基因的表达模式。AtFLA8 和 AtFLA10 这两个拟南芥基因在之前胚胎发育的微阵列研究中脱颖而出，使用启动子驱动的基因报告分析进行了进一步检查。我们还研究了栓皮栎 FLA 基因的表达，发现它们的表达部分与假定的 AtFLA 直向同源物的表达模式相似。我们认为 FLA 的功能组织是保守的，可能与被子植物胚胎发生和种子发育的基本方面有关。进行了系统发育研究，我们表明拟南芥 FLA 基因分类所描述的相同基本四亚组组织对于几种植物物种（即杨树、玉米和栓皮栎）的大多数拟南芥 FLA 直向同源物是有效的。