Plant surface lipid barriers: biosynthesis, regulation and protective functions

植物表面脂质屏障：生物合成、调节和保护功能

• 批准号: RGPIN-2016-06250
• 负责人: Rowland, Owen
• 金额: $ 4.44万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616187
• 关键词: Plant; surface; lipid; barriers; biosynthesis

Plants have specialized lipid-based barriers that play critical roles in controlling water movement, nutrient uptake, and gas exchange. These surface lipids also provide protection against various environmental stresses such as drought and pathogen attack. Plant aerial surfaces are coated with cuticle, which is composed mostly of polymerized lipids (cutin) and associated waxes. Likewise, suberin is a lipid-phenolic heteropolymeric barrier found in the cell walls of various external and internal tissues, including root endodermis and mature periderms (e.g. tuber skins and tree bark). As such, plant cuticles and suberized periderms form the largest biological interfaces on the planet, providing first points of contact with the surrounding, often hostile, environment. The long-term goal of my NSERC Discovery research program is to understand the regulated biosynthesis of plant surface lipid barriers and the mechanisms by which they exert their protective functions. My research group is using a combination of genetic and biochemical approaches to study plant surface lipid production, largely in the model plant Arabidopsis thaliana. Specifically, over the next five years, my research team will: (1) characterize a family of Myb transcription factors that control the regulation of suberin deposition, (2) uncover additional enzymes, transporters or regulators that are important for producing a fully functional suberin barrier, (3) provide insights into the mechanisms by which suberin and its associated waxes protect plants under periods of extreme stress, and (4) assess the potential roles of volatile fatty acids and methylketones produced by surface tissues in protection against insects and pathogens. Our overall goal is to gain fundamental knowledge regarding the synthesis and eco-physiological functions of surface lipid barriers, with the applied aim of providing information and tools for the development of stress tolerant crops. The improvement of crop drought tolerance is particularly attractive considering changing climate conditions are currently limiting agricultural production in large areas of the world, including Canada. Enhancing the natural defences of crops towards pathogens and pests is also an important strategy in our efforts to reduce crop losses to disease. In addition, plant surface lipids are rich in fatty alcohols, alkyl esters and oxygenated fatty acids, which are commercially valuable chemicals. Detailed knowledge of plant surface lipid biosynthesis is critical for harnessing this renewable chemical resource to its full potential, for example through the metabolic engineering of oilseed crops and microbes. Over the next 5 years, this research program will provide advanced training to 9 graduate (5 PhD, 4 MSc) and 20-25 undergraduate students in the areas of lipid biochemistry, genetic dissection, molecular biotechnology, and plant stress physiology.

植物具有特殊的脂质屏障，在控制水分运动、营养吸收和气体交换中起关键作用。这些表面脂质也提供保护，抵御各种环境压力，如干旱和病原体的攻击。植物的空气表面覆盖着一层角质层，角质层主要由聚合脂质（角质）和相关蜡质组成。同样，木质素是一种脂质-酚类异聚物屏障，存在于各种外部和内部组织的细胞壁中，包括根的内胚层和成熟的周皮（如块茎皮和树皮）。因此，植物的角质层和被埋没的周皮形成了地球上最大的生物界面，提供了与周围环境（通常是敌对的）的第一个接触点。我的NSERC发现研究计划的长期目标是了解植物表面脂质屏障的调节生物合成及其发挥其保护功能的机制。