Springer Clint J, Orozco Rebecca A, Kelly John K, Ward Joy K
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA.
New Phytol. 2008;178(1):63-67. doi: 10.1111/j.1469-8137.2008.02387.x.
Atmospheric CO(2) concentration ([CO(2)]) is rising on a global scale and is known to affect flowering time. Elevated [CO(2)] may be as influential as temperature in determining future changes in plant developmental timing, but little is known about the molecular mechanisms that control altered flowering times at elevated [CO(2)]. Using Arabidopsis thaliana, the expression patterns were compared of floral-initiation genes between a genotype that was selected for high fitness at elevated [CO(2)] and a nonselected control genotype. The selected genotype exhibits pronounced delays in flowering time when grown at elevated [CO(2)], whereas the control genotype is unaffected by elevated [CO(2)]. Thus, this comparison provides an evolutionarily relevant system for gaining insight into the responses of plants to future increases in [CO(2)]. Evidence is provided that elevated [CO(2)] influences the expression of floral-initiation genes. In addition, it is shown that delayed flowering at elevated [CO(2)] is associated with sustained expression of the floral repressor gene, FLOWERING LOCUS C (FLC), in an elevated CO(2)-adapted genotype. Understanding the mechanisms that account for changes in plant developmental timing at elevated [CO(2)] is critical for predicting the responses of plants to a high-CO(2) world of the near future.
全球范围内，大气二氧化碳浓度（[CO₂]）正在上升，且已知其会影响开花时间。在决定植物发育时间的未来变化方面，升高的[CO₂]可能与温度具有同样的影响力，但对于在升高的[CO₂]条件下控制开花时间改变的分子机制却知之甚少。利用拟南芥，比较了在升高的[CO₂]条件下选择出的高适应性基因型与未选择的对照基因型之间花起始基因的表达模式。所选基因型在升高的[CO₂]条件下生长时开花时间明显延迟，而对照基因型不受升高的[CO₂]影响。因此，这种比较为深入了解植物对未来[CO₂]升高的反应提供了一个具有进化相关性的系统。有证据表明升高的[CO₂]会影响花起始基因的表达。此外，研究表明，在适应了升高的[CO₂]的基因型中，升高的[CO₂]条件下开花延迟与花抑制基因FLOWERING LOCUS C（FLC）的持续表达有关。了解在升高的[CO₂]条件下植物发育时间变化的机制对于预测植物对不久的将来高CO₂环境的反应至关重要。
