Character Evolution Team, Royal Botanic Gardens, Kew, Richmond, Surrey, UK; School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, UK.
Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA.
Trends Plant Sci. 2021 Oct;26(10):1039-1049. doi: 10.1016/j.tplants.2021.06.001. Epub 2021 Jul 1.
Angiosperms show a remarkable range in genome size (GS), yet most species have small genomes, despite the frequency of polyploidy and repeat amplification in the ancestries of most lineages. It has been suggested that larger genomes incur costs that have driven selection for GS reduction, although the nature of these costs and how they might impact selection remain unclear. We explore potential costs of increased GS encompassing impacts on minimum cell size with consequences for photosynthesis and water-use efficiency and effects of greater nitrogen and phosphorus demands of the nucleus leading to more severe trade-offs with photosynthesis. We suggest that nutrient-, water-, and/or CO-stressed conditions might favour species with smaller genomes, with implications for species' ecological and evolutionary dynamics.
被子植物的基因组大小（GS）表现出显著的范围，但大多数物种的基因组都很小，尽管大多数谱系的祖先中存在多倍体和重复扩增的频率。有人认为，较大的基因组会产生成本，从而导致选择减少 GS，尽管这些成本的性质以及它们如何影响选择仍不清楚。我们探讨了增加 GS 的潜在成本，包括对最小细胞大小的影响，这会影响光合作用和水分利用效率，以及细胞核对更多氮和磷需求的影响，从而导致与光合作用的权衡更加严重。我们认为，营养物质、水和/或 CO 胁迫的条件可能有利于基因组较小的物种，这对物种的生态和进化动态有影响。
