Suberin: From Genes to Function

植物通过在表面涂上抗水材料来保护自己免受环境的侵害。例如，叶子和针叶上有一层蜡质角质层，它可以排斥水分，有助于防止真菌和细菌进入内部组织。同样，树木也有厚厚的树皮，树皮的细胞被一种叫做木质素的抗水物质包裹着。木质素也形成于根和块茎表面的表皮细胞中，在那里它有助于维持水分平衡，并作为土壤传播的疾病生物体的物理屏障。在根中，另一层被称为内胚层的细胞也含有木质素。这些细胞是水、营养物质和病原体进入维管组织之前的最后一道物理屏障，维管组织在整个植物中分配水和营养物质。由于其在调节水流和限制病原菌传播方面的重要作用，在抗旱和抗土传病害方面起着重要作用。以前我们已经证明大豆根系中亚黄素的含量与田间抗病性密切相关。我的研究项目主要是了解木素的形成（生物合成），包括植物控制它们形成的木素量的方式。我们目前专注于脂肪酸w-羟化酶（FAwH）基因的研究，这些基因来自于Solanum tuberosum（马铃薯，木质素生物合成模型）和Glycine max（大豆，木质素在病原体抗性中的作用模型）。这代表了从化学、生化和代谢组学方法到包括分子生物学方法的一个进展。随着对植物如何控制它们形成的木质素的位置和数量有了更好的了解，我们将能够找到在关键农作物中加强这一过程的方法，从而为植物提供增强的自然防御。

Plants protect themselves from the environment by coating their surfaces with water resilient materials. For example, a waxy cuticle that repels water covers leaves and needles and helps prevent fungi and bacteria from accessing the inner tissue. Similarly, trees form a thick bark, the cells of which are encrusted with a water resilient material named suberin. Suberin is also formed on the surfaces of roots and tubers, in the epidermis cells, where it helps maintain water balance and acts as a physical barrier to soil-borne disease organisms. In roots, another layer of cells, called the endodermis, also contains suberin. These cells act as the last physical barrier to water, nutrients and pathogens before they can enter the vascular tissue that distributes water and nutrients throughout the plant. Because if its importance in regulating water flow and restricting pathogen spread, suberin plays a major role in drought resistance and resistance to soil-borne disease agents. Previously we have shown that the amount of suberin in soybean roots is strongly correlated with field level disease resistance. My research program focuses on understanding the formation (biosynthesis) of suberin including the ways that plants control the amount of suberin that they formed. We are currently focusing on Fatty Acid w-Hydroxylase (FAwH) genes from both Solanum tuberosum (potato, a model for suberin biosynthesis) and Glycine max (soybean, a model for the role of suberin in pathogen resistance). This represents a progression from chemical, biochemical and metabolomic approaches to include a molecular biological approach. With a better understanding of how plants control the location and amount of suberin they form, we will be able to find ways to enhance this process in key agricultural crops thereby providing plants with enhanced natural defenses.