Mizrachi Eshchar, Verbeke Lieven, Christie Nanette, Fierro Ana C, Mansfield Shawn D, Davis Mark F, Gjersing Erica, Tuskan Gerald A, Van Montagu Marc, Van de Peer Yves, Marchal Kathleen, Myburg Alexander A
Department of Genetics, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0028, South Africa;
Genomics Research Institute, University of Pretoria, Pretoria 0028, South Africa.
Proc Natl Acad Sci U S A. 2017 Jan 31;114(5):1195-1200. doi: 10.1073/pnas.1620119114. Epub 2017 Jan 17.
As a consequence of their remarkable adaptability, fast growth, and superior wood properties, eucalypt tree plantations have emerged as key renewable feedstocks (over 20 million ha globally) for the production of pulp, paper, bioenergy, and other lignocellulosic products. However, most biomass properties such as growth, wood density, and wood chemistry are complex traits that are hard to improve in long-lived perennials. Systems genetics, a process of harnessing multiple levels of component trait information (e.g., transcript, protein, and metabolite variation) in populations that vary in complex traits, has proven effective for dissecting the genetics and biology of such traits. We have applied a network-based data integration (NBDI) method for a systems-level analysis of genes, processes and pathways underlying biomass and bioenergy-related traits using a segregating Eucalyptus hybrid population. We show that the integrative approach can link biologically meaningful sets of genes to complex traits and at the same time reveal the molecular basis of trait variation. Gene sets identified for related woody biomass traits were found to share regulatory loci, cluster in network neighborhoods, and exhibit enrichment for molecular functions such as xylan metabolism and cell wall development. These findings offer a framework for identifying the molecular underpinnings of complex biomass and bioprocessing-related traits. A more thorough understanding of the molecular basis of plant biomass traits should provide additional opportunities for the establishment of a sustainable bio-based economy.
由于其卓越的适应性、快速生长以及优良的木材特性，桉树人工林已成为生产纸浆、纸张、生物能源及其他木质纤维素产品的关键可再生原料（全球种植面积超过2000万公顷）。然而，大多数生物量特性，如生长、木材密度和木材化学性质，都是复杂性状，在长寿多年生植物中很难改良。系统遗传学是一种利用复杂性状存在差异的群体中多个层次的组成性状信息（如转录本、蛋白质和代谢物变异）的方法，已被证明对剖析此类性状的遗传学和生物学特性有效。我们应用了基于网络的数据整合（NBDI）方法，对一个分离的桉树杂交群体中与生物量和生物能源相关性状的基因、过程和途径进行系统水平分析。我们表明，这种整合方法可以将具有生物学意义的基因集与复杂性状联系起来，同时揭示性状变异的分子基础。发现为相关木质生物量性状鉴定的基因集共享调控位点，聚集在网络邻域中，并在木聚糖代谢和细胞壁发育等分子功能方面表现出富集。这些发现为确定复杂生物量和生物加工相关性状的分子基础提供了一个框架。对植物生物量性状分子基础的更深入理解应为建立可持续的生物基经济提供更多机会。
