Walter Julia, Lynch Fiona, Battchikova Natalia, Aro Eva-Mari, Gollan Peter J
Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland.
Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20014 Turku, Finland
J Exp Bot. 2016 Jun;67(13):3997-4008. doi: 10.1093/jxb/erw112. Epub 2016 Mar 24.
Calcium is integral to the perception, communication and adjustment of cellular responses to environmental changes. However, the role of Ca(2+) in fine-tuning cellular responses of wild-type cyanobacteria under favourable growth conditions has not been examined. In this study, extracellular Ca(2+) has been altered, and changes in the whole transcriptome of Anabaena sp. PCC 7120 have been evaluated under conditions replete of carbon and combined nitrogen. Ca(2+) induced differential expression of many genes driving primary cellular metabolism, with transcriptional regulation of carbon- and nitrogen-related processes responding with opposing trends. However, physiological effects of these transcriptional responses on biomass accumulation, biomass composition, and photosynthetic activity over the 24h period following Ca(2+) adjustment were found to be minor. It is well known that intracellular carbon:nitrogen balance is integral to optimal cell growth and that Ca(2+) plays an important role in the response of heterocystous cyanobacteria to combined-nitrogen deprivation. This work adds to the current knowledge by demonstrating a signalling role of Ca(2+) for making sensitive transcriptional adjustments required for optimal growth under non-limiting conditions.
钙对于细胞感知、传递及适应环境变化的反应至关重要。然而，尚未研究Ca(2+)在有利生长条件下对野生型蓝细菌细胞反应微调中的作用。在本研究中，改变了细胞外Ca(2+)，并在碳和化合态氮充足的条件下评估了鱼腥藻PCC 7120全转录组的变化。Ca(2+)诱导了许多驱动初级细胞代谢的基因的差异表达，碳和氮相关过程的转录调控呈现相反趋势。然而，发现这些转录反应对Ca(2+)调整后24小时内生物量积累、生物量组成和光合活性的生理影响较小。众所周知，细胞内碳氮平衡是细胞最佳生长所必需的，并且Ca(2+)在异形胞蓝细菌对化合态氮剥夺的反应中起重要作用。这项工作通过证明Ca(2+)在非限制条件下进行最佳生长所需的敏感转录调整中的信号作用，增加了当前的知识。
