Molecular mechanisms of phloem (bast) fibre development

大麻和亚麻等作物的韧皮部（或韧皮）纤维非常结实和长，按单位重量计算，其抗拉强度大于钢。我们感兴趣的是了解亚麻和大麻是如何发育出如此长而强壮的细胞的，以及如何优化这些细胞的特性，以从亚麻茎中制造出环保的纺织品和建筑材料。现在，在加拿大大约80万公顷的农田里，亚麻茎主要被当作废物来处理，这些农田种植亚麻以获取其油。韧皮部纤维的长度受到一种叫做侵入性生长的有趣过程的影响，即细胞在周围细胞之间生长。虽然侵入性生长在动物中比较常见，例如在神经发育过程中，但在植物中不太常见。我们实验室以前的工作使用了微阵列分析和二维凝胶电泳技术来鉴定与亚麻和大麻纤维发育相关的基因。我们发现的基因大多与纤维细胞壁的发育有关，目前我们正在对其中一些基因进行详细的表征。在拟议的研究中，我们希望更具体地研究控制亚麻和大麻韧皮部中纤维细胞长度和数量的基因。我们将再次使用微阵列分析，以及各种类型的突变筛选来识别这些基因，并随后表征它们的功能。筛选过程的一个直接结果将是确定更容易收获的亚麻品种，这将减少对环境不利的做法，如秸秆焚烧的需要。从长远来看，我们的研究将导致对植物细胞如何发育和交流的更好理解，这些信息将帮助育种者开发具有优化纤维特性的亚麻和大麻作物，用于新的产业。

The phloem (or bast) fibres of crops such as hemp and flax are remarkably strong and long, with a tensile strength greater than steel, on a per-weight basis. We are interested in learning how flax and hemp develop such long, strong cells, and how the properties of these cells might be optimized to make environmentally friendly textiles and building materials from flax stems, which are now largely treated as a waste product on the approximately 800,000 hectares of Canadian farmland that grows flax for its oil. The length of phloem fibres is affected by an interesting process called intrusive growth, whereby cells grow in between surrounding cells. Although intrusive growth is relatively well characterized in animals, for example, during nerve development, it is less common in plants. Previous work in our laboratory has used techniques called microarray analysis and two-dimensional gel electrophoresis to identify genes associated with fibre development in flax and hemp. The genes we identified are mostly involved in the development of the fibre cell wall, and we are currently characterizing some of these genes in detail. In the proposed research, we would like to look more specifically at the genes that control the length and number of fibre cells that develop in the phloem of flax and hemp. We will again use microarray analysis, as well as various types of mutant screening to identify these genes, and subsequently characterize their function. One immediate outcome of the screening process will be the identification of flax varieties that are easier to harvest, which will reduce the need for environmentally undesirable practices such as straw-burning. In the long term, our research will lead to an improved understanding of how plant cells develop and communicate, and this information will help breeders develop flax and hemp crops with optimized fibre properties for new industries.