Effects of foliar potassium concentration on morphology, ultrastructure and polyamine concentrations of Scots pine needles |
| |
Authors: | Jokela A Sarjala T Kaunisto S Huttunen S |
| |
Institution: | University of Oulu, Department of Biology, Botany, P.O. Box 333, FIN-90571 Oulu, Finland. |
| |
Abstract: | We examined the effects of three foliar potassium concentrations (high, intermediate and low) on the morphology, ultrastructure and polyamine concentrations of current-year and 1- and 2-year-old needles of 30-year-old Scots pine (Pinus sylvestris L.) trees. Foliar K concentration had only a slight effect on needle morphology. The sclerenchyma cell walls were thinner, the xylem area was larger, and the resin ducts were smaller in needles with a low K concentration than in needles with a high or intermediate K concentration. In addition, the bundle sheath cells were collapsed in needles having a low K concentration. The secondary growth of phloem tissue and the mesophyll area were greater in needles with a high or intermediate K concentration than in needles with a low K concentration, possibly indicating greater production of photoassimilates in these trees. At the ultrastructural level, mesophyll cells with enlarged central vacuoles and small vacuoles containing electron-dense material were common in needles having a low K concentration. Enlargement of the central vacuole coincided with an exponential increase in putrescine concentration in needles with a low K concentration, suggesting that the central vacuole may function as a storage site for putrescine. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|