EAGER: Somatic Mutations in Plants

虽然许多园艺学家和植物学家熟悉体细胞突变的经济方面，但体细胞突变作为进化变化的机制所起的作用尚不清楚。植物组织的模块化和分层性为突变的发生提供了基础，并通过细胞分裂和分化得以延续，潜在地创造了遗传变异的马赛克（在植物遗传变异内）。基因改变的组织可以通过配子进行有性繁殖，也可以通过产生块茎、鳞茎、茎状茎、根茎和种子进行无性繁殖，从而导致亲本和体细胞改变的后代的分化。尽管人们普遍认为体细胞突变是可能发生的，但在一株植物内究竟能产生多少变异并使其永续存在，这是未知的。为了解决这个问题，我们建议使用模式植物系统黑棉杨、毛杨和Illumina测序（重测序）对同一个体不同植物部位（根、茎、叶）的遗传（基因水平）变异进行全基因组扫描，具体解决个体基因水平上常见突变的情况。最终，这项研究的结果将为解决长期以来关于自然界体细胞突变的重要性及其进化重要性的争论迈出第一步，包括植物可能能够进化地应对不断变化的环境条件的方式，以及植物内部的遗传变异是否可以防止害虫和病原体破坏其寄主植物的防御。一名研究生和一名本科生将获得基因组学和生物信息学方面的培训。

Although many horticulturists and botanists are familiar with the economic aspects of somatic mutation, the role somatic mutation plays as a mechanism for evolutionary change is unknown. The modular and layered nature of plant tissues provides the basis for mutations to occur and be perpetuated through cell division and differentiation, potentially creating mosaics of genetic variability (within plant genetic variability). Genetically altered tissues can be perpetuated sexually through gametes or asexually through the production of tubers, bulbs, runners, rhizomes, and seeds, leading to the divergence of parental and somatically altered offspring. In spite of wide acknowledgment that somatic mutation can occur, it is unknown how much variation can be generated and perpetuated within an individual plant. To address this issue we propose conducting a genome-wide scan of genetic (gene level) variation within different plant parts of the same individual (roots, stems, leaves) using the model plant system black cottonwood, Populus trichocarpa, and Illumina sequencing (resequencing), specifically addressing how common mutations are at the level of the gene within an individual. Ultimately, the results of this study will take an initial step toward resolving a long-standing debate over the importance of somatic mutations in nature and their evolutionary importance, including ways in which plants may be able to evolutionarily cope with changing environmental conditions and whether within plant genetic variation can prevent pests and pathogens from breaking the defenses of their host plants. One graduate and one undergraduate student will gain training in genomics and bioinformatics.