Developmental Genetics of Corolla Tube Formation: A Key Morphological Innovation During Angiosperm Evolution

花冠管形成的发育遗传学：被子植物进化过程中的关键形态创新

• 批准号: 1755373
• 负责人: Yaowu Yuan
• 金额: $ 58.8万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1755373&HistoricalAwards=false
• 关键词: Developmental; Genetics; Corolla; Tube; Formation

About one third of the ~300,000 flowering plant species (e.g., petunia, snapdragon, primrose, rhododendron) produce flowers with petals fused into a tubular structure referred to as the corolla tube. The corolla tube encloses and protects the nectaries and reproductive organs. Differences in the length, width, and curvature of the corolla tube have led to an endless variety of differently shaped flowers that attract specialized groups of pollinators (e.g., beeflies, hawkmoths, hummingbirds, nectar bats). Because of its importance in plant reproduction, the corolla tube is considered a key morphological innovation that contributes to plant diversification and speciation. This study employs a new genetic model system, monkeyflowers (Mimulus lewisii), to identify and characterize the genes responsible for corolla tube development, including the genes responsible for coordinated organ fusion and the generation of a diversity of corolla tube shape. The flower images, pollination videos, and interactive, multimedia illustrations resulting from this project will be incorporated into a new Plant Biology section on the nationally and internationally recognized Learn.Genetics website as online educational resources for K-16 students. Multi-disciplinary training in genetics, development, and evolution includes post-doctoral associates, graduate students and undergraduate students, including members of under-represented groups enrolled in the McNair Scholars Program at UConn.This study leverages recently developed genomic resources, stable transgenic tools, and chemically induced mutants of monkeyflowers (Mimulus) to identify and characterize genes that control corolla tube formation. Results from preliminary work in the investigator's laboratory allows the formulation of a new conceptual model for the developmental genetic control of corolla tube formation. At the heart of the model is auxin signaling that mediates coordinated growth between the bases of the initially separate petal primordia and the inter-primordial regions. Upstream of this core module is the genetic regulatory network (GRN) controlling lateral expansion of the petal primordia, essentially the same GRN that controls leaf adaxial/abaxial polarity and lamina growth. Downstream of this core module lie the organ boundary genes that suppress localized tissue growth if not repressed by auxin signaling. Two specific aims will be pursued to test these hypotheses: (i) Determine the functional roles of the major regulators of leaf polarity in corolla tube formation using in situ hybridization, ectopic gene expression, and RNA interference in the model species Mimulus lewisii. (ii) Identify additional components of the GRN controlling corolla tube formation by bulk segregant analyses of several additional non-allelic mutants of M. lewisii with unfused corollas. Genetic interactions among the newly identified genes and the known leaf polarity regulators will be determined by generating double or higher order combinatorial mutants and transgenic lines. RNA-Seq analyses of selected regulatory mutants and transgenic lines of the leaf polarity regulators will be conducted to identify downstream genes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

约有30万种开花植物物种（例如矮牵牛，snapdragon，primrose，rhododendron）中约有三分之一的花朵产生花瓣，融合到管状结构中，称为花冠管。花冠管包围并保护蜜蜂和生殖器官。花冠管的长度，宽度和曲率的差异导致了各种不同形状的花朵，吸引了专业的授粉媒介（例如，蜂虫，霍克莫斯，蜂鸟，蜂鸟，花蜜蝙蝠）。由于其在植物繁殖中的重要性，花冠管被认为是有助于植物多元化和物种形成的关键形态创新。这项研究采用了一种新的遗传模型系统，即Monkeyflowers（Mimulus lewisii）来识别和表征负责花冠管发育的基因，包括负责协调器官融合的基因和花冠管形的多样性。该项目产生的花图像，授粉视频和互动式的多媒体插图将被纳入全国和国际认可的Learn.ther.genetics网站上的新植物生物学部分，作为K-16学生的在线教育资源。在遗传学，发展和进化方面进行的多学科培训包括专业的伙伴，研究生和本科生，包括参加UConn的麦克奈尔学者计划的成员形成。研究者实验室的初步工作的结果允许制定一种新的概念模型，以形成花冠管的发展遗传控制。该模型的核心是生长素信号传导，它介导了最初分离的花瓣原始区域和育间区域之间的协调生长。该核心模块的上游是控制花瓣原始横向膨胀的遗传调节网络（GRN），基本上与控制叶片伸展/递减极性和层状生长的GRN相同。该核心模块的下游是器官边界基因，即使不被生长素信号抑制，它会抑制局部组织生长。将采用两个具体的目标来检验这些假设：（i）使用原位杂交，异位基因表达和RNA干扰在模型物种Mimulus Lewisii中确定叶片极性主要调节剂在花冠管形成中的功能作用。 （ii）通过对Lewisii的几个其他非平行性突变体和未经融合的花冠，确定了控制花冠管形成的其他组件。新鉴定的基因和已知叶片极性调节因子之间的遗传相互作用将通过产生双重或高阶组合突变体和转基因线来确定。将对选定的调节突变体和叶极性调节剂的转基因线的RNA-seq分析进行识别，以识别下游基因。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛影响的审查标准通过评估来进行评估的。

项目成果

The leaf polarity factors SGS3 and YABBYs regulate style elongation through auxin signaling in Mimulus lewisii

路易斯酸浆草 (Mimulus lewisii) 中叶片极性因子 SGS3 和 YABBYs 通过生长素信号调节花柱伸长

• DOI: 10.1111/nph.17702
• 发表时间: 2021
• 期刊: New Phytologist
• 影响因子: 9.4
• 作者: Ding, Baoqing;Li, Jingjian;Gurung, Vandana;Lin, Qiaoshan;Sun, Xuemei;Yuan, Yao‐Wu
• 通讯作者: Yuan, Yao‐Wu

Comparative analysis of corolla tube development across three closely related Mimulus species with different pollination syndromes

• DOI: 10.1111/ede.12368
• 发表时间: 2021-01-07
• 期刊: EVOLUTION & DEVELOPMENT
• 影响因子: 2.9
• 作者: Gurung, Vandana;Yuan, Yao-Wu;Diggle, Pamela K.
• 通讯作者: Diggle, Pamela K.