Structure, genetic variability and regulation of the transcriptome in relation to wood formation in forest trees

木材的特性源于遗传编码的发育程序，即次生维管生长或木材形成。木材的形成是一个复杂的过程，因为它受到生长季节和树木寿命的环境条件变化的影响。基因表达是树木整合遗传信息和环境线索以制造木材的机制之一。我的项目旨在通过对全基因组基因表达的研究，识别和探索基因型变异与木材性能之间的分子联系。因此，我的研究目标是为木材等复杂性状的遗传结构提供见解。转录组由存在于细胞或组织中的一整套RNA转录本组成，代表可能表达的基因。我们将使用新的微阵列来调查树木基因组中几乎所有基因的表达。不同的子项目也将依靠定量PCR和其他方法来研究rna池的调节和调控。具体目标是：(1)建立针叶树的参考档案，包括动态转录组的不同观点，并为我们的研究和其他人的研究提供参考框架；(2)描述与木材形成过程相关的转录组模块，作为日变化和季节变化、树木空间位置和干旱等环境因素的函数；(3)在群体水平上研究转录物丰度的变异和遗传控制，以深入了解复杂性状的遗传结构；(4)通过选择调控基因的功能获得实验，研究树木木材形成过程中转录组调控的机制和网络。这项研究将支持博士和硕士学生的培养。它还将导致林业应用，即通过发展森林树木的分子育种。

Wood properties result from a genetically encoded program of development, known as secondary vascular growth or wood formation. Wood formation is a complex process because it is influenced by variations in environmental conditions over the growth season and the life of a tree. Gene expression is one of the mechanisms by which trees integrate genetic information and environmental cues in order to make wood. My program aims to identify and explore molecular links between genotypic variation and wood properties, through the study of genome-wide gene expression. The goal of my research is thus to provide insights into the genetic architecture of complex traits like wood. The transcriptome is comprised of the entire set of RNA transcripts present in a cell or tissue and represents the genes that may be expressed. We will use new microarrays to survey the expression of nearly all the genes present in the genomes of trees. The different subprojects will also rely on quantitative PCR and other methods to investigate the modulation and regulation of RNAs pools. Specific objectives are to (1) Develop reference profiles for conifer trees, comprised of diverse views of the dynamic transcriptome and provide a reference framework for our research and that of others; (2) Delineate the transcriptome modules that are linked to the processes underlying wood formation, as a function of daily and seasonal variation, spatial position in the tree and of environmental factors like drought; (3) Investigate the variability and genetic control of transcript abundance at the population level as a means to gain insights into the genetic architecture underlying complex traits; (4) Study mechanisms and networks underlying transcriptome regulation during wood formation in trees, through gain-of-function experiments with selected regulatory genes. The research will support the training of Ph. D. and M. Sc students. It will also result in applications in forestry, namely through the development of molecular breeding of forest trees.