College of Agronomy, Northwest A&F University, Xianyang 712100, Shaanxi, China.
College of Landscape Architecture and Arts, Northwest A&F University, Xianyang 712100, Shaanxi, China.
Int J Mol Sci. 2019 Apr 20;20(8):1945. doi: 10.3390/ijms20081945.
The fasciclin-like arabinogalactan proteins (FLAs) play important roles in plant development and adaptation to the environment. FLAs contain both fasciclin domains and arabinogalactan protein (AGP) regions, which have been identified in several plants. The evolutionary history of this gene family in plants is still undiscovered. In this study, we identified the gene family in 13 plant species covering major lineages of plants using bioinformatics methods. A total of 246 genes are identified with gene copy numbers ranging from one () to 49 (). These FLAs are classified into seven groups, mainly based on the phylogenetic analysis of plant FLAs. All FLAs in land plants contain one or two fasciclin domains, while in algae, several FLAs contain four or six fasciclin domains. It has been proposed that there was a divergence event, represented by the reduced number of fasciclin domains from algae to land plants in evolutionary history. Furthermore, introns in genes are lost during plant evolution, especially from green algae to land plants. Moreover, it is found that gene duplication events, including segmental and tandem duplications are essential for the expansion of gene families. The duplicated gene pairs in gene family mainly evolve under purifying selection. Our findings give insight into the origin and expansion of the gene family and help us understand their functions during the process of evolution.
纤层素类似阿拉伯半乳聚糖蛋白（FLAs）在植物发育和适应环境中发挥着重要作用。FLAs 既含有纤层素结构域，又含有阿拉伯半乳聚糖蛋白（AGP）区域，这在几种植物中都有发现。该基因家族在植物中的进化历史尚未被揭示。在这项研究中，我们使用生物信息学方法在 13 种植物物种中鉴定了该基因家族。共鉴定出 246 个基因，基因拷贝数从 1 个到 49 个不等。这些 FLA 根据植物 FLA 的系统发育分析主要分为七个组。所有陆地植物中的 FLA 都含有一个或两个纤层素结构域，而藻类中的几个 FLA 含有四个或六个纤层素结构域。据推测，在进化历史中，纤层素结构域的数量从藻类减少到陆地植物，发生了一次分歧事件。此外，基因中的内含子在植物进化过程中丢失，特别是从绿藻到陆地植物。此外，研究发现基因复制事件，包括片段和串联重复，对基因家族的扩张至关重要。基因家族中重复的基因对主要在净化选择下进化。我们的研究结果深入了解了该基因家族的起源和扩张，并有助于我们理解它们在进化过程中的功能。
