Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P. 58030, Morelia, Michoacán, Mexico.
Plant Cell Environ. 2017 Sep;40(9):1887-1899. doi: 10.1111/pce.12993. Epub 2017 Jul 26.
Transcriptional regulation of gene expression influences plant growth, environmental interactions and plant-plant communication. Here, we report that population density is a key factor for plant productivity and a major root architectural determinant in Arabidopsis thaliana. When grown in soil at varied densities from 1 to 32 plants, high number of individuals decreased stem growth and accelerated senescence, which negatively correlated with total plant biomass and seed production at the completion of the life cycle. Root morphogenesis was also a major trait modulated by plant density, because an increasing number of individuals grown in vitro showed repression of primary root growth, lateral root formation and root hair development while affecting auxin-regulated gene expression and the levels of auxin transporters PIN1 and PIN2. We also found that mutation of the Mediator complex subunit PFT1/MED25 renders plants insensitive to high density-modulated root traits. Our results suggest that plant density is critical for phase transitions, productivity and root system architecture and reveal a role of Mediator in self-plant recognition.
转录调控基因表达影响植物生长、环境相互作用和植物-植物通讯。在这里，我们报告说种群密度是植物生产力的关键因素，也是拟南芥根系结构的主要决定因素。当在土壤中以 1 到 32 株的不同密度生长时，大量个体减少了茎的生长并加速了衰老，这与生命周期结束时的总植物生物量和种子产量呈负相关。根系形态发生也是受植物密度调节的主要特征，因为在体外生长的个体数量增加会抑制主根生长、侧根形成和根毛发育，同时影响生长素调节基因的表达和生长素转运蛋白 PIN1 和 PIN2 的水平。我们还发现，中介复合物亚基 PFT1/MED25 的突变使植物对高密度调节的根特性不敏感。我们的研究结果表明，植物密度对于阶段转变、生产力和根系结构至关重要，并揭示了中介在自我植物识别中的作用。
