背景:DELLA蛋白,一类GA信号抑制子,属于植物特异性核蛋白的GRAS家族。DELLA基因家族成员编码在植物发育和非生物胁迫反应中具有不同功能的转录调节因子。迄今为止,DELLA已在各种植物物种中被鉴定,比如拟南芥,家蝇,毛果杨,和其他陆地植物。DELLA家族基因的大部分信息来自拟南芥,而对蓝莓中的DELLA基因家族知之甚少。
结果:在这项研究中,我们在蓝莓中鉴定了三个DELLA基因(Vacciniumdarrowii,VdDELLA)并提供了VdDELLA基因家族的完整概述,描述染色体定位,蛋白质性质,保守域,主题组织,和系统发育分析。三个VdDELLA成员,含有两个高度保守的DELLA结构域和GRAS结构域,分布在三个染色体上。此外,顺式作用元件分析表明,VdDELLA基因可能在蓝莓发育过程中起关键作用,激素,和应激反应。使用定量实时PCR(qRT-PCR)的表达分析揭示所有三种VdDELLA基因在各种组织中差异表达。VdDELLA2是所有指定组织中最高表达的VdDELLA,在成熟水果中表达最高。此外,所有三个VdDELLA基因都对不同的非生物胁迫做出了积极的反应。基于qRT-PCR分析,VdDELLA2可能是V.darrowii响应盐胁迫的关键调节剂,而VdDELLA1和VdDELLA2可能在冷应激反应中起重要作用。在干旱胁迫下,所有三个VdDELLA基因都参与介导干旱反应。此外,它们在拟南芥原生质体中与核标记的瞬时共定位证明了它们的转录调节作用。
结论:在这项研究中,在达罗维氏弧菌基因组中鉴定出三个VdDELLA基因。三个VdDELLA基因与C.moschataDELLA基因密切相关,S.lycopersicumDELLA基因,和M.domesticaDella基因,分别,表明它们具有相似的生物学功能。表达分析表明,VdDELLA基因在蓝莓果实发育中是高效的。不同胁迫条件下的表达模式揭示了对盐反应的VdDELLA基因的差异表达,干旱,冷压力。总的来说,这些结果丰富了我们对VdDELLA基因的进化关系和潜在功能的理解,为进一步研究植物产量和植物抗性的遗传改良提供了有价值的信息。
BACKGROUND: The DELLA proteins, a class of GA signaling repressors, belong to the GRAS family of plant-specific nuclear proteins. Members of DELLA gene family encode transcriptional regulators with diverse functions in plant development and abiotic stress responses. To date, DELLAs have been identified in various plant species, such as Arabidopsis thaliana, Malus domestica, Populus trichocarpa, and other land plants. Most information of DELLA family genes was obtained from A. thaliana, whereas little is known about the DELLA gene family in blueberry.
RESULTS: In this study, we identified three DELLA genes in blueberry (Vaccinium darrowii, VdDELLA) and provided a complete overview of VdDELLA gene family, describing chromosome localization, protein properties, conserved domain, motif organization, and phylogenetic analysis. Three VdDELLA members, containing two highly conserved DELLA domain and GRAS domain, were distributed across three chromosomes. Additionally, cis-acting elements analysis indicated that VdDELLA genes might play a critical role in blueberry developmental processes, hormone, and stress responses. Expression analysis using quantitative real-time PCR (qRT-PCR) revealed that all of three VdDELLA genes were differentially expressed across various tissues. VdDELLA2 was the most highly expressed VdDELLA in all denoted tissues, with a highest expression in mature fruits. In addition, all of the three VdDELLA genes actively responded to diverse abiotic stresses. Based on qRT-PCR analysis, VdDELLA2 might act as a key regulator in V. darrowii in response to salt stress, whereas VdDELLA1 and VdDELLA2 might play an essential role in cold stress response. Under drought stress, all of three VdDELLA genes were involved in mediating drought response. Furthermore, their transiently co-localization with nuclear markers in A. thaliana protoplasts demonstrated their transcriptional regulator roles.
CONCLUSIONS: In this study, three VdDELLA genes were identified in V. darrowii genome. Three VdDELLA genes were closely related to the C. moschata DELLA genes, S. lycopersicum DELLA genes, and M. domestica DELLA genes, respectively, indicating their similar biological functions. Expression analysis indicated that VdDELLA genes were highly efficient in blueberry fruit development. Expression patterns under different stress conditions revealed the differentially expressed VdDELLA genes responding to salt, drought, and cold stress. Overall, these results enrich our understanding of evolutionary relationship and potential functions of VdDELLA genes, which provide valuable information for further studies on genetic improvement of the plant yield and plant resistance.