Reproductive development in dwarf mistletoes (genus Arceuthobium): the male's tale, explosive seed discharge, and 'environmental' microscopy.

矮槲寄生（Arceuthobium 属）的生殖发育：雄性的故事、爆炸性种子排放和“环境”显微镜。

• 批准号: 327214-2012
• 负责人: RossFriedman, Cynthia
• 金额: $ 1.82万
• 依托单位: Thompson Rivers University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=549009
• 关键词: Reproductive; development; dwarf; mistletoes; genus

Dwarf mistletoes (genus Arceuthobium, Santalaceae) are parasitic flowering plants that infect economically important conifers, seriously compromising their health. As effective maturation of pollen, its dispersal, and seed dissemination all govern the success of Arceuthobium as a parasite, understanding developmental and dispersive events will identify key stages toward which a control program may ultimately be devised. The proposed work will use Arceuthobium americanum (the lodgepole pine dwarf mistletoe) collected near Kamloops, British Columbia and target three short-term objectives. In Objective 1, pollen development will be delineated using advanced tools for microscopy. My students and I will employ light microscopy (LM) and transmission electron microscopy (TEM) to explore developmental anatomy and morphology of anthers and pollen. We will also use fluorescence microscopy (FM) and TEM in conjunction with specific antibodies to determine changes in pollen cell wall chemistry. In Objective 2, the role of aquaporins (membrane water channels) in seed dispersal will be defined in collaboration with Dr. Ralf Kaldenhoff at Technische Universität Darmstadt, Germany and Dr. Carl Douglas at the University of British Columbia. Arceuthobium species are standouts among flowering plants, as they forcibly discharge their single seed from the fruit via hydrostatic pressure. We will identify aquaporin genes in Arceuthobium and monitor their expression using real-time PCR and in situ localization. In Objective 3, real-time changes in dehiscing anthers, intercepted pollen, discharging fruit, and released seeds will be examined with 'environmental" scanning electron microscopy (SEM). Through the Canada Foundation for Innovation, my lab has acquired an SEM capable of imaging living specimens under varying pressures, temperatures, and relative humidity. This powerful tool will enable critical questions regarding real-time events in anthers, germinating pollen, mature fruit, and seeds to be answered. The proposed work will train 13 undergraduate and 3 graduate students as well as contribute information that can be used to shape management decisions regarding this notorious forest pest.

矮槲寄生（属Arceuthobium，檀香科）是寄生开花植物，感染经济上重要的针叶树，严重损害他们的健康。由于花粉的有效成熟，其传播和种子传播都控制着Arceuthobium作为寄生虫的成功，因此了解发育和分散事件将确定最终可能设计控制程序的关键阶段。拟议的工作将使用在不列颠哥伦比亚省坎卢普斯附近采集的Arceuthobium americanum（小杆松矮槲寄生），并针对三个短期目标。在目标1中，将使用先进的显微镜工具描绘花粉发育。我和我的学生将利用光学显微镜（LM）和透射电子显微镜（TEM）来探索花药和花粉的发育解剖学和形态学。我们还将使用荧光显微镜（FM）和TEM结合特异性抗体，以确定花粉细胞壁化学的变化。在目标2中，水通道蛋白（膜水通道）在种子传播中的作用将与德国达姆施塔特工业大学的Ralf Kaldenhoff博士和不列颠哥伦比亚省大学的Carl道格拉斯博士合作定义。Arceuthobium物种是显花植物中的佼佼者，因为它们通过静水压力强行从果实中排出单个种子。我们将鉴定Arceuthobium中的水通道蛋白基因，并使用实时PCR和原位定位监测其表达。在目标3中，将用“环境”扫描电子显微镜（SEM）检查开裂花药、拦截花粉、排出果实和释放种子的实时变化。通过加拿大创新基金会，我的实验室获得了一台扫描电镜，能够在不同的压力、温度和相对湿度下对活体标本进行成像。这个强大的工具将能够回答有关花药，萌发花粉，成熟果实和种子中实时事件的关键问题。这项拟议的工作将培训13名本科生和3名研究生，并提供可用于制定有关这种臭名昭著的森林害虫的管理决策的信息。