Calcium nutrition has a significant influence on wood formation in poplar.
To test the effects of calcium on wood formation, Populus tremula x Populus tremuloides clones were supplied with Hoagland solution modified in its calcium contents. Energy-dispersive X-ray analysis (EDXA) revealed an increase in calcium in the phloem, the cambium and the xylem elongation zone with increasing Ca(2+) supply in the nutrient solution. Using light and electron microscopy, a strong impact was shown on the cambial and the elongation zones under calcium starvation. Using Fourier transform infrared (FTIR) spectroscopy on wood and bark cells formed under calcium starvation, we detected a reduction of some absorptions, such as carbonyl and methoxy groups from S-lignin. Also, a significant reduction in fiber length was detected with decreasing calcium supply in the nutrient solution. High-performance liquid chromatography (HPLC) analysis revealed a large increase in sugar concentrations in the leaves, but reduced concentrations in the bark under Ca(2+) deficiency. In conclusion, our results show a significant influence of calcium on the structure, chemistry and physiology of wood formation. Thus, efficient Ca(2+) supply has to be considered a decisive factor in wood formation.
Lautner
Silke
S
Department for Wood Biology, TU München, Winzerer Strasse 45, 80797 München, Germany.
Ehlting
Barbara
B
Chair of Tree Physiology, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee, 53/54, 79110 Freiburg, Germany.
Windeisen
Elisabeth
E
Department for Wood Biology, TU München, Winzerer Strasse 45, 80797 München, Germany.
Rennenberg
Heinz
H
Chair of Tree Physiology, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee, 53/54, 79110 Freiburg, Germany.
Matyssek
Rainer
R
Chair of Plant Ecophysiology, TU München, Am Hochanger 13, 85354 Freising, Germany.
Fromm
Jörg
J
Department for Wood Biology, TU München, Winzerer Strasse 45, 80797 München, Germany.
D002118:Calcium / Q000032:analysis*; D002241:Carbohydrates / Q000032:analysis; D018547:Plant Stems / Q000166:cytology; D032107:Populus / Q000737:chemistry* / Q000166:cytology / Q000254:growth & development; D017550:Spectroscopy, Fourier Transform Infrared; D014934:Wood / Q000737:chemistry* / Q000648:ultrastructure
D002241:Carbohydrates; D002118:Calcium