Abstract

Genome size in plant species is closely associated with many intracellular and environmental factors, which makes it important for adaptation and evolution. Although research on genome size changes has a long history, the problem continues to be challenging because many factors affecting this evolutionary process are still unknown. Despite substantial effort to investigate genome size changes in major plant lineages, the present-day picture remains rather static because the age of plant species is not always taken into consideration. We attempted to systematically investigate genome size dynamics in multiple genera of diploid seed plants. A remarkably strong intrageneric linear dependence between the genome size and evolutionary age of species was found. This linearity of intrageneric genome size dynamics has persisted over millions of years, suggesting gradual changes in DNA content unrelated to the natural selection process. Our results also reveal that some outlier species did not follow this general trend and could go through drastic changes in genome size over a short period of evolutionary time. We conclude that genome size within the genera of many diploid seed plant species is not stochastic and follows a linear dependence on the evolutionary age of the species.

中文翻译：

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二倍体种子植物多个属的基因组大小动态

摘要

植物物种的基因组大小与许多细胞内和环境因素密切相关，这对于适应和进化很重要。尽管对基因组大小变化的研究已有很长的历史，但是由于影响这一进化过程的许多因素仍然未知，因此该问题仍然具有挑战性。尽管为研究主要植物谱系的基因组大小变化做出了巨大努力，但由于并不总是考虑植物物种的年龄，因此目前的状况仍然是静止的。我们试图系统地研究二倍体种子植物多个属中的基因组大小动态。发现在基因组大小和物种进化年龄之间非常明显的属内线性依赖性。遗传内基因组大小动力学的这种线性关系已经持续了数百万年，提示DNA含量的逐渐变化与自然选择过程无关。我们的结果还表明，一些离群物种没有遵循这一总体趋势，并且可能会在短时间内的进化过程中经历基因组大小的急剧变化。我们得出的结论是，许多二倍体种子植物物种的属内的基因组大小不是随机的，而是线性依赖于该物种的进化年龄。