Institute for Wood Biology, University of Hamburg, Hamburg, Germany.
Tree Physiol. 2010 Sep;30(9):1140-7. doi: 10.1093/treephys/tpq024. Epub 2010 May 2.
Potassium and calcium are essential for tree metabolism and various physiological processes related to growth. In recent years, special interest was therefore accorded to the effect of both cations on cambial activity and xylem development. Various studies revealed a distinct correlation between potassium as well as calcium nutrition and wood formation. When poplar trees were grown under low K(+) or Ca²(+) regimes, the cambial activity as well as the seasonal rate of wood increment and the vessel size were significantly reduced. Molecular, biochemical and electrophysiological investigations indicate (i) a strong involvement of specific K(+) channels in the regulation of xylem cell expansion and (ii) a significant influence of Ca²(+) on the onset of cambial reactivation after winter dormancy as well as on wood structure and chemistry. These studies highlight the important role of potassium as well as calcium in xylogenesis. Based on that knowledge, further research will be directed towards a better understanding of the mechanisms governing K(+)- as well as Ca²(+)-dependent wood formation.
钾和钙对树木的新陈代谢和与生长有关的各种生理过程至关重要。近年来，人们特别关注这两种阳离子对形成层活动和木质部发育的影响。各种研究表明，钾和钙营养与木材形成之间存在明显的相关性。当杨树在低钾或低钙条件下生长时，形成层活动以及季节性的木材增量和导管尺寸显著降低。分子、生化和电生理学研究表明：（i）特定的钾通道在木质部细胞扩张的调节中起着重要作用；（ii）钙离子对冬季休眠后形成层重新激活的开始以及对木材结构和化学成分有显著影响。这些研究强调了钾和钙在木质部形成中的重要作用。基于这一认识，进一步的研究将致力于更好地理解控制钾依赖和钙依赖的木材形成的机制。
