Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Nanjing Forestry University, Nanjing, China.
Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
Plant Biol (Stuttg). 2022 Aug;24(5):874-886. doi: 10.1111/plb.13431. Epub 2022 May 19.
Homeodomain-leucine zipper (HD-Zip) proteins are plant-specific transcription factors that play important roles in different biological processes, especially leaf development. However, no studies to date have identified the HD-Zip genes in Liriodendron chinense nor characterized their functions. We identified the HD-Zip genes in L. chinense by analysing the phylogeny, chromosome location, structure, conserved motif, cis-regulatory elements, synteny, post-transcriptional regulation and expression patterns of these genes during leaf development. A total of 36 LcHD-Zip genes were identified and divided into four subfamilies (HD-Zip I to IV). Synteny analysis revealed that segmental duplication was the main force driving the expansion of LcHD-Zip genes. These 36 LcHD-Zip genes exhibited 11 different expression patterns. Pattern 1, 2, 3, 4, 6, 7, 8 and 9 genes may play important roles in leaf development, such as leaf initiation, leaf polarity establishment, leaf shape development, phytohormone-mediated leaf growth and leaf epidermal structure formation. Four HD-Zip III genes were targeted by microRNAs (miRNAs), and the miR165/166a-HD-Zip regulatory module formed regulated leaf initiation and leaf polarity establishment. Overall, LcHD-Zip genes play key roles in leaf development of L. chinense. This work provides a foundation for the functional verification of HD-Zip genes identified in this study.
同源域亮氨酸拉链（HD-Zip）蛋白是植物特有的转录因子，在不同的生物学过程中发挥着重要作用，特别是在叶片发育过程中。然而，迄今为止，尚未有研究鉴定出鹅掌楸中的 HD-Zip 基因，也未对其功能进行表征。我们通过分析鹅掌楸中这些基因的系统发育、染色体定位、结构、保守基序、顺式调控元件、基因同线性、转录后调控以及在叶片发育过程中的表达模式，鉴定出了鹅掌楸中的 HD-Zip 基因。共鉴定出 36 个 LcHD-Zip 基因，分为四个亚家族（HD-Zip I 到 IV）。基因同线性分析表明，片段复制是驱动 LcHD-Zip 基因扩张的主要力量。这 36 个 LcHD-Zip 基因表现出 11 种不同的表达模式。模式 1、2、3、4、6、7、8 和 9 基因可能在叶片发育中发挥重要作用，如叶片起始、叶片极性建立、叶片形状发育、植物激素介导的叶片生长和叶片表皮结构形成。四个 HD-Zip III 基因被 microRNAs（miRNAs）靶向，miR165/166a-HD-Zip 调控模块形成了对叶片起始和叶片极性建立的调控。总的来说，LcHD-Zip 基因在鹅掌楸的叶片发育中起着关键作用。这项工作为该研究中鉴定的 HD-Zip 基因的功能验证提供了基础。
