Zhang Man, Cheng Wenhui, Wang Jia, Cheng Tangren, Lin Xinlian, Zhang Qixiang, Li Cuiling
Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Engineering Research Center of Landscape Environment of Ministry of Education, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing 100083, China.
Flower Research Institute, Meizhou Academy of Agriculture and Forestry Sciences, Meizhou 514071, China.
Plants (Basel). 2023 Dec 14;12(24):4159. doi: 10.3390/plants12244159.
Callose is an important polysaccharide composed of beta-1,3-glucans and is widely implicated in plant development and defense responses. Callose synthesis is mainly catalyzed by a family of callose synthases, also known as glucan synthase-like (GSL) enzymes. Despite the fact that GSL family genes were studied in a few plant species, their functional roles have not been fully understood in woody perennials. In this study, we identified total of 84 genes in seven plant species and classified them into six phylogenetic clades. An evolutionary analysis revealed different modes of duplication driving the expansion of GSL family genes in monocot and dicot species, with strong purifying selection constraining the protein evolution. We further examined the gene structure, protein sequences, and physiochemical properties of 11 GSL enzymes in and observed strong sequence conservation within the functional domain of PmGSL proteins. However, the exon-intron distribution and protein motif composition are less conservative among genes. With a promoter analysis, we detected abundant hormonal responsive cis-acting elements and we inferred the putative transcription factors regulating . To further understand the function of GSL family genes, we analyzed their expression patterns across different tissues, and during the process of floral bud development, pathogen infection, and hormonal responses in species and identified multiple GSL gene members possibly implicated in the callose deposition associated with bud dormancy cycling, pathogen infection, and hormone signaling. In summary, our study provides a comprehensive understanding of GSL family genes in species and has laid the foundation for future functional research of callose synthase genes in perennial trees.
胼胝质是一种由β-1,3-葡聚糖组成的重要多糖，广泛参与植物发育和防御反应。胼胝质合成主要由一类胼胝质合成酶催化，也被称为类葡聚糖合成酶（GSL）。尽管在一些植物物种中对GSL家族基因进行了研究，但在木本多年生植物中它们的功能作用尚未完全了解。在本研究中，我们在七种植物物种中总共鉴定出84个基因，并将它们分为六个系统发育分支。进化分析揭示了驱动单子叶植物和双子叶植物中GSL家族基因扩张的不同复制模式，强烈的纯化选择限制了蛋白质进化。我们进一步研究了11种GSL酶的基因结构、蛋白质序列和理化性质，观察到PmGSL蛋白功能域内有很强的序列保守性。然而，基因间的外显子-内含子分布和蛋白质基序组成不太保守。通过启动子分析，我们检测到大量激素响应顺式作用元件，并推断出调控的假定转录因子。为了进一步了解GSL家族基因的功能，我们分析了它们在不同组织中的表达模式，以及在物种花芽发育、病原体感染和激素响应过程中的表达模式，并鉴定出多个可能与芽休眠循环、病原体感染和激素信号相关的胼胝质沉积有关的GSL基因成员。总之，我们的研究全面了解了物种中的GSL家族基因，为多年生树木中胼胝质合成酶基因的未来功能研究奠定了基础。
