Constructing Plant Cuticle Barriers: from molecular architecture to mechanical integrity

陆生植物通过聚集在表皮或周皮细胞壁中的不溶的疏水分子来调节它们与环境的相互作用：切削素、Suberin和蜡共享一些构建块和形成途径。为了了解这些重要保护膜的大分子结构和机械性能，将以基因沉默的番茄果实和马铃薯块茎以及几种模式植物的叶片为研究对象。生物物理测量的协调协议将把植物覆盖物的生物合成与其分子结构和宏观属性(如机械完整性和环境持久性)联系起来。该项目有利于粮食作物产量和植物凋落物的回收利用，还有助于涂料、纺织品和涂料的设计。从高中到博士后水平的跨学科培训团队将进行这项研究，这也将形成非科学人员本科实验室课程的基础。该计划的长期目标是将当前保护植物角质层和周皮的现象学转变为对疏水薄膜多功能屏障功能的全面预测方案。除了与粮食作物保护和植物凋落物回收有关的好处外，项目成果还可以为超疏水涂料、纺织品和涂料的设计提供参考。遗传、分析和生物力学技术的最新进展使人们有可能理解从分子到宏观的长度尺度上的植物角质层结构，从生物合成到生物降解的发展，以及表面或整体的机械完整性。本项目将研究番茄(Solanum Lycopsicum)和马铃薯(Solanum Tuberosum)植物的角质层和周皮的生物合成、大分子组织和机械性能。作为补充，抗化学降解和调节植物角质层功能的聚合物将从结构上进行鉴定。具体的假说将被测试以解决几个问题：两种水果角质素合酶的专一性；基因沉默的马铃薯块茎周皮的代谢重新路由；纤维化的马铃薯细胞壁的大分子组织；角质层和周皮的纳米力学和抗张强度；切割素和Suberin的环境持久性。

Terrestrial plants regulate their interactions with the environment via insoluble hydrophobic molecules assembled within epidermal or peridermal cell walls: cutins, suberins, and waxes that share some building blocks and formation pathways. To understand the macromolecular structure and mechanical performance of these essential protective membranes, gene-silenced tomato fruits and potato tubers as well as leaves from several model plants will be targeted for study. A coordinated protocol of biophysical measurements will link the biosynthesis of plant coverings with their molecular architectures and macroscopic attributes such as mechanical integrity and environmental persistence. The project can benefit food crop yields and recycling of plant litter, also aiding the design of paints, textiles, and coatings. Interdisciplinary training teams spanning high school through postdoctoral levels will conduct this research, which will also form the basis of an undergraduate laboratory curriculum for non-scientists.The long-term objective of this program is to transform the current phenomenology of protective plant cuticles and periderms into a comprehensive predictive scheme for the versatile barrier functions of hydrophobic membranes. In addition to benefits related to food crop protection and plant litter recycling, the project outcomes can inform the design of superhydrophobic paints, textiles, and coatings. Recent improvements in genetic, analytical, and biomechanical technologies are making it possible to achieve an understanding of plant cuticular architecture that spans length scales from molecular to macroscopic, development from biosynthesis to biodegradation, and mechanical integrity at the surface or in bulk. This project will examine the biosynthesis, macromolecular organization, and mechanical performance of cuticles and periderms from tomato (Solanum lycopersicum) and potato (Solanum tuberosum) plants with known genomes. As a complement, the polymers that resist chemical degradation and modulate plant cuticular function will be identified structurally. Specific hypotheses will be tested to address several issues: specificity of two fruit cutin synthase enzymes; metabolic rerouting of gene-silenced potato tuber periderms; macromolecular organization of suberized potato cell walls; nanomechanics and tensile strength of cuticles and periderms, respectively; environmental persistence of cutins and suberins.