Apoplastic permeability barriers: a central regulating factor enabling plant resistance to abiotic stresses and dormancy induction.

质外体渗透屏障：使植物抵抗非生物胁迫和休眠诱导的中心调节因素。

• 批准号: RGPIN-2018-05853
• 负责人: Tanino, Karen
• 金额: $ 2.91万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=666518
• 关键词: Apoplastic; permeability; barriers; central; regulating

Barriers have played a pivotal role enabling successful environmental adaptation throughout plant evolutionary history. Fundamental factors conserved in the progenitors of land plants provided essential tools for plant colonization on land. Development of barriers such as cuticular layers and complex polymers in the apoplast (middle lamella, cell wall) are among key factors enabling avoidance of water loss and preventing disease invasion. Thus, apoplastic complexes are often at the core of higher plant resistance mechanisms to both abiotic and biotic stresses. While the close relationship between multiple stresses and their importance to successful plant adaptation is well recognized, studies have not widely examined the role of specific structural apoplastic barriers as a common mediator across stresses and developmental processes. The cell wall fraction is a biphasic structure consisting of cellulose microfibrils held together by a gel-like matrix. This gel-like matrix constitutes up to two-thirds of the cell wall's dry weight and composed of cross-linking extensin glycoproteins and non-cellulosic polysaccharides including pectins. Pectins are dynamic, the major regulatory molecule dictating the porosity, permeability and therefore, barriers, of Type I cell walls but the precise mechanism is still not resolved. The functional ability to form pectin gels, regulate porosity and permeability is controlled through Pectin Methylesterase (PME), calcium, sucrose and modified by temperature. However, most of the evidence comes from the food processing literature. Remarkably, only a limited number of such studies in plants exist and we are not aware of any currently focussed specifically on sucrose, Ca2+ and PME as regulatory points controlling apoplast permeability barriers to enhance broad range plant adaptation to multiple stresses. Global warming has also placed more recent focus on temperature-driven environmental adaptation. Hypothesis: temperature-mediated plant stress and tree dormancy responses are induced through alterations in pectin apoplastic permeability barriers regulated by PME, calcium and sucrose. Objectives: 1) To demonstrate a reduction in apoplast permeability increases freezing stress resistance; 2) To determine if PME, sucrose and/or calcium levels are the key regulating factors to freezing, salt and drought stress resistance through apoplast permeability changes. 3) To determine if temperature-mediated dormancy induction is regulated by changes in apoplast permeability through PME, sucrose and/or calcium. Discovery apoplast permeability is at the centre of a range of abiotic stress resistances will have widespread impact, creating new tools for crop improvement and begins to provide insight into the role of barriers and regulation of water flow--fundamental principles to all plant growth, development and adaptation to the environment. ***

障碍发挥了关键作用，使得在植物进化史上成功的环境适应能力。土地植物祖细胞中保守的基本因素为土地上的植物定植提供了重要的工具。障碍物（如表皮层和质体中的复杂聚合物（中部薄片，细胞壁））的发展是避免水分流失和预防疾病入侵的关键因素。因此，凋亡复合物通常是对非生物和生物胁迫的较高植物耐药机制的核心。虽然多种压力与成功植物适应的重要性之间的密切关系已得到充分认识，但研究并未广泛研究特定的结构性质外层障碍作为在压力和发育过程中的共同介体的作用。 细胞壁分数是一种双相结构，由纤维素微纤维组成，由凝胶样基质组成。这种类似凝胶的基质构成了细胞壁干重的三分之二，由交联的延伸蛋白糖蛋白和包括果胶在内的非纤维素多糖组成。 果胶是动态的，是I型细胞壁的孔隙率，渗透性以及障碍物的主要调节分子，但仍未解决精确的机制。 形成果胶凝胶，调节孔隙率和渗透率的功能能力通过果胶甲基酯酶（PME），钙，蔗糖并通过温度进行修饰。 但是，大多数证据来自食品加工文献。值得注意的是，只有有限的植物研究存在，我们并不意识到当前的任何专门针对蔗糖，Ca2+和PME，作为控制质体渗透性障碍的调节点，以增强植物对多种压力的广泛适应性。全球变暖还将最近关注温度驱动的环境适应。假设：温度介导的植物应激和树木休眠反应是通过PME，钙和蔗糖调节的果胶质塑料渗透性屏障的改变而引起的。 目的：1）证明凋亡渗透性的降低会增加冻伤的抗应力； 2）确定PME，蔗糖和/或钙水平是否是通过渗透渗透性变化而冻结，盐和干旱胁迫抗性的关键调节因素。 3）确定温度介导的休眠诱导是否受到通过PME，蔗糖和/或钙的凋亡渗透性变化的调节。发现凋亡的渗透性位于一系列非生物压力抗性的中心，将产生广泛的影响，为作物改善创造新的工具，并开始深入了解障碍的作用和水流量的作用 - 对所有植物生长，开发和适应环境的植物生长和适应环境的原理。 ***