Needle Waxes

The white points on the Spruce needle are stomatal openings with their antechambers filled with epicuticular wax.

The epicuticular wax layer (white points, see photograph) on the needle surface from young and mature conifer trees has been chemically analysed and viewed with a scanning electron microscopy with respect to the needle development at different environmental conditions (SO₂ and ozone concentration, climate and site). In each wax sample 68 components in 12 substance classes were quantified.

The most frequent components were secondary alcohols, diols, free omega-hydroxy and n-fatty acids, as well as estolides (longchain esters from omega-hydroxy fatty acids, fatty acids, fatty alcohols and fatty diols, typical in conifer waxes). The variability in the content of the needle wax substance classes was similar within young spruce of the same genotype under different treatments to that within genetically different mature trees at different sites. The 10-nonacosanole content in the wax of the young cloned trees increased, but that of free omega-hydroxy fatty acids decreased with increasing ozone dose (varied by controlled application and according to the ozone concentrations at the different sites).

Waxes cannot be chemically altered by air pollutants because of a certain chemical inertia. However, during wax formation 10-nonacosanole is formed before the estolides, and therefore the above correlation appears to indicate an ozone-induced retardation of the wax formation. The amount and structure of the waxes changed with needle age and weather conditions, whereas SO₂- or drought stress did not lead to significant changes.

Publications

• Scheidegger C., Günthardt-Goerg M., Frey B., 1997: Blattoberflächen und Spaltöffnungen. Bündner Wald 3: 23-34.
• Günthardt-Goerg M.S., Keller T., Matyssek R., Scheidegger C., 1994: Environmental effects on Norway spruce needle wax. Eur. J. For. Path. 24: 92-111.
• Günthardt-Goerg M.S., 1994: The effect of the environment on the structure, quantity and composition of spruce needle wax. In: Percy K.E., Cape J.N., Jagels R., Simpson, C.J. (eds.), Air Pollutants and the Leaf Cuticle. NATO ASI. Ecol. Sci. G 36: 165-174. Springer, Berlin.
• Günthardt-Goerg M.S., 1991: Die Einwirkung von Luftschadstoffen und Klimafaktoren auf die Wachsschicht von Fichtennadeln. In: Stark M. (ed.), Lufthaushalt, Luftverschmutzung und Waldschäden in der Schweiz, Ergebnisse aus dem Nationalen Forschungsprogramm 14, Band 5: Luftschadstoffe und Wald: 107-118. Verlag der Fachvereine, Zürich.
• Günthardt-Goerg M.S., 1989: Site-dependent changes in the epicuticular wax structure of spruce. In: Bucher J.B., Bucher-Wallin I. (eds.), Air Pollution and Forest Decline. Proc. 14th Int. Meeting for Specialists in Air Pollution Effects on Forest Ecosystems, IUFRO P2.05, Interlaken, Switzerland 2: 416-418. EAFV, Birmensdorf.
• Günthardt-Goerg M.S., Keller T., 1988: Cuticular features and conductivitiy of needle diffusate in spruce. Commission of the European Communities, Air Pollut. Res. Report 15: 316-322.
• Goerg-Günthardt M.S., 1988: Auswirkungen von Ozon auf die Nadeloberfläche eines Fichtenklones. ARGE ALP, Symposium Verteilung und Wirkung von Photooxidantien im Alpenraum, GSF-Bericht 17: 382-390, 662-664.
• Günthardt-Goerg M.S., 1988: Wax of some Fulgoroidea. In: Vidano C., Arzone A. (eds.), Proc. 6th Auchen. Meeting, Turin, Italy, 7-11 Sept. 1987: 129-133.
• Günthardt Goerg M.S., Rossi F.A., 1987: Der Einfluss von Fichtennadelwachs auf Nadelzersetzung und Erlenkeimung. Z. Pflanzenernähr. Bodenkd. 150: 86-93.
• Günthardt-Goerg M.S., Keller T., 1987: Some effects of long term ozone fumigations on Norway spruce. II. Epicuticular wax and stomata. Trees 1: 145-150.
• Goerg-Günthardt M.S., Keller T., 1987: Needle surface after a fumigation with low concentrations of SO2 or O3. Commission of the European Communities, Air pollut. Res. Report 4: 159-160.
• Günthardt-Goerg M.S., 1987: Epicuticular wax formation on needles of Picea abies and Pinus cembra. In: Stumph P.K., Mudd J.B., Nes W.D. (eds.), The metabolism, structure, and function of plant lipids: 557-559. Plenum press, New York.
• Günthardt-Goerg M.S., 1986: Epicuticular wax of needles of Pinus cembra, Pinus sylvestris and Picea abies. Eur. J. For. Pathol. 16: 400-408.
• Günthardt M.S., 1985: Entwicklung der Spaltöffnungen und der epicuticulären Wachsschicht bei Pinus cembra und Picea abies. Bot. Helv. 95: 5-12.
• Günthardt M.S., 1984: Epicuticular wax of Picea abies needles. In: Siegenthaler P.-A., Eichenberger W. (eds.), Structure, function, and metabolism of plant lipids: 499-502. Elsevier, Amsterdam.
• Günthardt M.S., Wanner H., 1982: Die Menge des epicuticulären Wachses auf Nadeln von Pinus cembra L. und Picea abies (Karsten) in Abhängigkeit von Nadelalter und Standort. Flora 172: 125-137.
• Günthardt M.S., Wanner H., 1982: Veränderungen der Spaltöffnungen und der Wachsstruktur mit zunehmendem Nadelalter bei Pinus cembra L. und Picea abies (L.) Karsten. Bot. Helv. 92: 47-60.

Contact

• Madeleine S. Goerg-Günthardt