Transcriptome Responses to Environmental Conditions in Loblolly Pine Roots

木材占美国生产的所有工业材料价值的25%，每年，木材衍生产品的价值等于或超过几乎所有其他农作物的价值。然而，生产森林面积的损失，加上对纸张和海外廉价纤维供应的需求增加，给美国公司带来了巨大的压力，要求他们提高每英亩的木材产量，特别是在东南部的森林。不幸的是，我们对树木生物学的有限了解构成了实现必要的生产力提高以跟上消费者对木材产品不断增长的需求的重大障碍。火炬松木材形成组织中表达的基因正在努力编目（火炬松），在美国东南部的主要商业树种，虽然木材特异性基因的收集提供了一个很好的一步，以改善对控制木材形成的基本遗传单位的理解，对于许多将被证明对提高未来森林生产力至关重要的基因来说，它将是不完整的。该项目将开发数千个新基因的集合主要来源于具有商业和生物学意义的其它松树组织，特别是经受各种生物和非生物胁迫的根。该项目的数据将尽最大可能与其他专注于松树基因组研究的项目的数据相结合，以便为研究界创建一套无缝的资源，例如一套全面的unigene。这种全面的unigene集将形成DNA微阵列的基础，将被用来识别基因的表达变化响应各种环境和发展的线索，特别是那些响应压力，树木可能会经历时，受到密集的管理制度。这些基因的鉴定将有助于更好地了解树木用于应对环境和生物压力的分子机制，并将有助于开发技术和工具，如靶向微阵列，可用于近实时监测造林做法对树木生长和发育的影响。例如，响应特定矿物质或营养缺乏的根基因的微阵列可以使造林学家在检测到表型反应之前判断新的施肥方案是否可能改善生长速度或木材质量。这些新技术将为解决目前限制美国东南部森林生产力的生物限制提供手段。

Wood accounts for 25% of the value of all industrial materials produced in the U.S., and on an annual basis, the value of wood-derived products equals or exceeds that of virtually every other agricultural crop. However, losses in production forest acreage, coupled with increasing demands for paper and cheap fiber supplies from overseas, have put intense pressure on U.S. companies to increase wood yields per acre, particularly in southeastern forests. Unfortunately, our limited understanding of tree biology constitutes a significant barrier to attaining the productivity gains necessary to keep pace with the rising consumer demand for wood products. Efforts are underway to catalog genes expressed in the wood-forming tissues of loblolly pine (Pinus taeda), the predominant commercial tree species in the southeastern U.S. Although this collection of wood-specific genes provides an excellent step toward improved understanding of the basic genetic units governing wood formation, it will be incomplete with respect to many genes that will prove critical for increasing the productivity of tomorrow's forests.This project will develop a collection of several thousand new genes derived primarily from other pine tissues of commercial and biological significance, in particular roots undergoing a variety of biotic and abiotic stresses. To the greatest extent possible, data from this project will be integrated with that from other projects focused on genomic studies of pine so as to create a seamless set of resources, such as a comprehensive unigene set, for the research community. Such comprehensive unigene sets will form the basis of DNA microarrays that will be used to identify genes whose expression varies in response to various environmental and developmental cues, particularly those responding to stresses that trees would likely experience when subjected to intensive management regimes. Identification of such genes will provide for better understanding of the molecular mechanisms trees use to respond to environmental and biological stresses, and will enable the development of techniques and tools, such as targeted microarrays, that could be used to monitor in near real-time the effects of silvicultural practices on tree growth and development. For example, microarrays of root genes that respond to specific mineral or nutrient deficiencies could allow silviculturalists to judge whether or not a new fertilization regimen was likely improve growth rates or wood quality well before the phenotypic responses could be detected. Such new techniques will provide the means for addressing current biological constraints that limit forest productivity in the southeastern U.S.