Integrative Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Plant Cell Environ. 2011 Sep;34(9):1577-85. doi: 10.1111/j.1365-3040.2011.02354.x. Epub 2011 Jun 28.
Symbiotic and parasitic relationships can alter the degree of endoreduplication in plant cells, and a limited number of studies have documented this occurrence in root cells colonized by arbuscular mycorrhizal (AM) fungi. However, this phenomenon has not been tested in a wide range of plant species, including species that are non-endopolyploid and those that do not associate with AM fungi. We grew 37 species belonging to 16 plant families, with a range of genome sizes and a range in the degree of endopolyploidy. The endoreduplication index (EI) was compared between plants that were inoculated with Glomus irregulare and plants that were not inoculated. Of the species colonized with AM fungi, 22 of the 25 species had a significant increase in endopolyploid root nuclei over non-mycorrhizal plants, including species that do not normally exhibit endopolyploidy. Changes in the EI were strongly correlated (R(2) = 0.619) with the proportion of root length colonized by arbuscules. No change was detected in the EI for the 12 non-mycorrhizal species. This work indicates that colonization by symbiotic fungi involves a mechanism to increase nuclear DNA content in roots across many angiosperm groups and is likely linked to increased metabolism and protein production.
共生和寄生关系可以改变植物细胞内内复制的程度，已有少数研究记录了丛枝菌根（AM）真菌定殖的根细胞中发生的这种现象。然而，这一现象尚未在包括非内多倍体植物和不与 AM 真菌相关的植物在内的广泛植物物种中进行测试。我们种植了 37 种来自 16 个科的植物，涵盖了不同的基因组大小和内多倍体程度范围。我们比较了接种 Glomus irregulare 的植物和未接种的植物之间的内复制指数（EI）。在被 AM 真菌定殖的物种中，25 种中有 22 种具有明显增加的内多倍体根核，包括通常不表现内多倍体的物种。EI 的变化与丛枝菌根定殖的根长比例强烈相关（R²=0.619）。在 12 种非菌根植物中，EI 没有变化。这项工作表明，共生真菌的定殖涉及一种机制，即在许多被子植物群中增加根内的核 DNA 含量，这可能与代谢和蛋白质产生的增加有关。
