Structural, physiological and biochemical aspects of embryo development in vivo and in vitro

体内和体外胚胎发育的结构、生理和生化方面

• 批准号: 6704-2007
• 负责人: Yeung, Edward
• 金额: $ 4.01万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=361338
• 关键词: Structural; physiological; biochemical; aspects; embryo

Apical meristems are located at each growing point and are specialized for the production of new cells for the plant body.  The importance of meristems in plant growth and development can be summarized by a simple statement from Professor Ian Sussex's review "The meristems make the plant" (Cell 56: 225, 1989). In the past funding period, we demonstrated that shoot meristem initiation is sensitive to auxin perturbation.  Furthermore, during in vitro embryogenesis, although a shoot meristem is formed, it is not stably determined as its organization deteriorates upon prolong culture. The root meristem, on the other hand, requires auxin for development. These observations suggest that expression of the meristem genes and hence the cell fate could be altered by auxin levels and factors from the embryonic environment. We also established that the redox state of both the cell and its surrounding environment can modulate in vitro embryo development.  The redox environment can influence the quality of the embryos produced, especially the shoot apical meristem.There are still many important, unanswered questions regarding meristem initiation and its determination process.  At present, we have in our collection a number of Arabidopsis meristem-related enhancer-trap lines with GUS (beta-glucuronidase) as the marker gene.  In the next funding period, we will make use of these enhancer-trap lines to study meristem formation and the role of auxin and other medium additives during in vitro development.  The advantage of using the GUS marker gene is that once this gene is subsequently translated, we can stain for the enzyme activity which gives a blue color.  By studying changes in the color pattern, we can study the activities of various meristem genes during the course of meristem development.  We will further investigate the importance of the redox environment on embryo development.  The white spruce system will be used. The role of the redox compounds, i.e. reduced and oxidized glutathione on embryogenic tissue proliferation and programmed cell death will be studied using histological, histochemical, and biochemical methods.

顶端分生组织位于每个生长点，专门用于为植物体产生新细胞。分生组织在植物生长和发育中的重要性可以通过Ian Sussex教授的综述“The meristems make the plant”（Cell 56：225，1989）中的一个简单陈述来概括。在过去的研究中，我们证明了茎分生组织的发生对生长素的干扰是敏感的。此外，在离体胚胎发生过程中，虽然茎分生组织形成，但随着培养时间的延长，其组织会退化，因此不能稳定地确定。另一方面，根分生组织的发育需要生长素。这些观察结果表明，分生组织基因的表达，因此细胞的命运可以改变生长素水平和胚胎环境的因素。我们还证实了细胞及其周围环境的氧化还原状态可以调节离体胚的发育。氧化还原环境可以影响产生的胚的质量，特别是茎尖分生组织。关于分生组织的起始及其决定过程，还有许多重要的、未回答的问题。目前，我们收集了许多拟南芥分生组织相关的增强子捕获系，（β-葡萄糖醛酸酶）作为标记基因。在下一个资助期，我们将利用这些增强子捕获系来研究分生组织的形成以及生长素和其他培养基添加剂在离体发育过程中的作用。使用GUS标记基因的优点是，一旦该基因随后被翻译，我们可以对酶的活性进行染色，使其呈现蓝色。通过研究颜色模式的变化，我们可以研究分生组织发育过程中各种分生组织基因的活性。我们将进一步研究氧化还原环境对胚胎发育的重要性。我们将使用白色云杉系统。将使用组织学、组织化学和生物化学方法研究氧化还原化合物（即还原型和氧化型谷胱甘肽）对胚胎发生组织增殖和程序性细胞死亡的作用。