The Cellular and Molecular Bases of Penetration Resistance to Fungal Pathogens in Arabidopsis

植物病害每年都会对农业生产和粮食供应造成毁灭性的影响。然而，为了应对病原体的攻击，大多数植物都进化出了物理和化学防御系统，以抵御企图的入侵。在植物表面，病原菌的穿透尝试通常是通过沉积额外的细胞壁材料形成的靶向细胞壁结合(CWA)，如木质素、痂和结构蛋白。长期以来，穿透抗性一直被认为是植物基础防御反应中最突出的方面之一。最近发现了几个与穿透抗性有关的基因，包括主穿透(PEN)基因(PEN1、PEN2和PEN3)。然而，病原体穿透部位细胞壁物质的生物合成和沉积的基本细胞途径仍然很大程度上是未知的。我的研究项目致力于了解模式植物拟南芥和作物对真菌病原菌攻击的渗透抗性的分子和细胞机制。我们最近发现，由肌动蛋白细胞骨架调控的细胞运输介导了CWAs，并对穿透阻力做出了贡献。这项研究的目的是：(A)阐明在病原体穿透部位促进CWAs的生化和分子途径；(B)了解协调病原体穿透部位细胞壁物质运输和沉积的细胞运输机制；以及(C)揭示参与调节宿主细胞中肌动蛋白细胞骨架动态重排的分子成分。我们将应用分子生物学、细胞生物学、生物化学、遗传学和基因组学方法以及高通量和经典植物病理学技术来实现这些目标。这一研究将为理解植物抵御病原菌侵袭的防御机制带来重大进展。我的研究计划还将为设计战略提供有价值的见解，以产生持久的抗病作物，抵御更广泛的植物病原体。

Plant diseases have a devastating impact on agricultural production and food supply every year. In response to pathogen attack, most plants however, have evolved physical and chemical defenses to ward off attempted invasions. On the plant surface, pathogen penetration attempts are often met by targeted cell wall appositions (CWAs) formed by the deposition of additional cell wall materials such as lignin, callose and structural proteins. Penetration resistance has long been recognized as one of the most prominent facets of plant basal defense responses. Several loci involved in the penetration resistance have recently been identified including major PENETRATION (PEN) genes (PEN1, PEN2, and PEN3). However, the cellular pathways underlying the biosynthesis and deposition of cell wall materials at the pathogen penetration site remain largely unknown. My research program has been devoted to understanding the molecular and cellular mechanisms of penetration resistance in the model plant Arabidopsis and crop species against fungal pathogen attack. We have recently shown that cellular trafficking regulated by the actin cytoskeleton mediates CWAs and contributes to the penetration resistance. The objectives of the proposed research are: (a) to elucidate biochemical and molecular pathways that contribute to CWAs at the pathogen penetration site, (b) to understand cellular trafficking mechanisms that coordinate transport and deposition of cell wall materials at pathogen penetration sites, and (c) to uncover molecular components that are involved in the regulation of dynamic rearrangement of the actin cytoskeleton in host cells in response to pathogen attack. We will apply molecular biology, cell biology, biochemistry, genetics, and genomics approaches along with high throughput and classical plant pathology techniques to achieve these objectives. This research will lead to significant advances in the understanding of plant defense mechanisms against pathogen attack. My research program will also provide valuable insights into designing strategies for the generation of durable disease resistant crops against a broader spectrum of plant pathogens.