毛白杨响应旱胁迫与木质部发育的基因组遗传结构与协同作用机制

Genome-wide dissection of genetic architecture and coordinated regulatory mechanism between drought response and xylem development in long-lived tree germplasm resources, is key theory of high-efficiency molecular breeding approaches for elite cultivars with high-quality and drought-resistant improvement. Herein, on the basis of 30× coverage genome re-sequencing data for the germplasm populations of Populus tomentosa (300 individuals) , our project would systematically launch four research topics as follows: 1) Analysis of population differentiation of physiological, biochemical and wood-property phenotypic variations under drought-tolerance in germplasm resources of P. tomentosa; 2) Identification of potential genomic signals of selection respond to the local adaptation of P. tomentosa; 3) Dissection of additive, dominant, and epistatic effects of genome-wide SNPs underlying physiological, biochemical and wood-property traits under drought-tolerance by using Genome-wide association studies (GWASs); 4) Validation of the balanced regulatory mechanism of key genes throughout the integrated genetic networkers using RNA-Seq and CRISPR-Cas9 technologies. Therefore, our study could uncover the genome-wide integrated networkers between drought response and xylem development of P. tomentosa, elaborate the coordinated regulatory mechanism of key node genes, and finally develop major-effect gene marker for high-quality and drought-resistant elite cultivars. This work will provide an importance model for dissecting the genomic basis underlying complex quantitative traits, drive innovative progress in tree molecular breeding platform, and therefore have key theoretical and practical values.

系统揭示林木种质资源响应旱胁迫与木质部发育的基因组遗传结构与协同作用机制，是开展优质、抗旱型新品种高效选育的理论基础。本项目以毛白杨种质资源群体重测序（300株，30×覆盖度）为基础，系统开展：（1）种质资源群体响应旱胁迫生理生化与木材品质性状的表型遗传变异分析；（2）伴随种源进化的基因组适应性选择区域的检测与注释；（3）利用GWAS策略解析响应旱胁迫生理生化与木材品质性状的基因组SNPs联合遗传效应（加性、显性与上位性）；（4）利用RNA-Seq与CRISPR/Cas9技术验证平衡调控旱胁迫与木质部发育的关键基因功能。研究结果将揭示杨树旱胁迫与木质部发育的基因组整合遗传网络，阐明关键节点基因协同调控旱胁迫与木质部发育的分子机制，以此发掘优质、抗旱育种价值的高效基因标记。本研究为解析林木复杂数量性状的基因组遗传机制提供模式系统，将推动林木分子育种技术平台的建设，具有重要科学与应用价值。

系统揭示林木种质资源响应旱胁迫与木质部发育的基因组遗传结构与协同作用机制，是开展优质、抗旱型新品种高效选育的理论基础。本项目以毛白杨种质资源群体重测序（300株，3 0×覆盖度）为基础，系统开展：（1）种质资源群体响应旱胁迫生理生化与木材品质性状的表型遗传变异分析；（2）伴随种源进化的基因组适应性选择区域的检测与注释；（3）利用GWAS 策略解析响应旱胁迫生理生化与木材品质性状的基因组SNPs遗传效应及鉴定关键候选基因PtobZIP18；（4）利用分子实验与杨树遗传转化技术验证平衡调控旱胁迫与木质部发育的关键基因功能。研究结果揭示杨树旱胁迫与木质部发育的基因组整合遗传网络，阐明关键节点基因PtobZIP18协同调控旱胁迫与木质部发育的分子机制，以此发掘优质、抗旱育种价值的高效基因标记。本研究为解析林木复杂数量性状的基因组遗传机制提供模式系统，将推动林木分子育种技术平台的建设，具有重要科学与应用价值。