Non-foliar photosynthesis and its contribution to the overall carbon balance of plants


  • Guido Aschan Institute of Applied Botany, University of Duisburg Essen
  • Hardy Pfanz Institute of Applied Botany, University of Duisburg, Essen, Germany



floral photosynthesis, aerial roots, orchids, Helleborus, chlorophyll fluorescens


In addition to the green leaves, commonly considered as the main sources of photosynthate production, higher plants can potentially use nearly all vegetative and reproductive structures to perform photosynthetic CO2 assimilation. Green leaves, stems and green sterile flower organs, optimized for light harvesting and photosynthetic performance, are characterized by net photosynthetic assimilation utilizing mainly the atmospheric carbon dioxide. In contrast, chlorophyll-containing bark and wood tissue, most fruit, root and fertile flower organs are primary sub­ ordinated to non-photosynthetic functions, but typically perform an effective internal CO2 recycling using the respiratory released CO2. Non-foliar photosynthesis, either manifested as positive net photosynthesis or internal CO2 refixation is regarded as an important strategy of additional carbon acquisition. The main strategies of additional carbon acquisition by non-foliar chlorophyllous organs are illustrated, presenting selected examples developed in reproductive as well as in vegetative plant structures.


ANTLFINGER A. E. & L. F. WENDEL 1997: Reproductive effort and floral photosynthesis in Spiranthes cernua (Orchidaceae). Am. J. Bot. 84: 769-780. DOI:

AscHAN G. & H. PFANZ 2003: Non- foliar photosynthesis - a strategy of additional carbon acquisition. Flora 198: 81-97. DOI:

BAZZAZ F. A., R. W. CARLSON & J. L. HARPER 1979: Contribution to reproductive effort by photosynthesis of flowers and fruits. Nature 279: 554-555. DOI:

BENZING D. H. & D. W. OTT 1981: Vegetative reduction in epiphytic Bromeliaceae and Orchidaceae: its origin and significance. Biotropica 13 (2): 131-140. DOI:

BENZING D. H. & W. T. PocKMAN 1989: Why do nonfoliar green organs of leafy orchids fail to exhibit net photosynthesis? Lindleyana 4: 53-60.

BENZING D. H., W. E. FRIEDMAN, G. PEIBRSON & A. RENFROW 1983: Shootlessness, velamentous roots, and the pre-eminence of Orchidaceae in the epiphytic biotope. Am. J. Bot. 70: 121-133. DOI:

BLANKE M. M. & F. LENZ 1989: Fruit photosynthesis - a review. Plant Cell Environ. 12: 31-46. DOI:

CLEMENT C., P..MISCHLER, M. BURRUS & J. C. AuDRAN 1997A: Characteristics of the photosynthetic apparatus and CO2-fixation in the flower bud of Lilium. I. Corolla. Int. J. Plant Sci. 158: 794-800. DOI:

CLEMENT C., P. MISCHLER, M. BURRUS & J.C. AuDRAN 1997B: Characteristics of the photosynthetic apparatus and CO2-fixation in the flower bud of Lilium. II. Anther. Int. J. Plant Sci. 158: 801-810. DOI:

COCKBURN W., GoH C. J. & P. N. AvADHANI 1985: Photosynthetic carbon assimilation in a shootless orchid, Chiloschista usneoides (DON) LDL. Plant Physiol. 77: 83-86. DOI:

DuEKER J. & J. ARDITTI 1968: Photosynthetic 14CO -fixation by green Cymbidium (Orchidaceae) flowers. Plant Physiol. 43: 130-132. DOI:

Dycus A. M. & L. KNuDSON 1957: The role of the velamen of the aerial roots of orchids. - Botan. Gaz. 119: 78-87. DOI:

GALEN C., T. E. DAWSON & M. L. STANTON 1993: Carpels as leaves: meeting the carbon cost of reproduction in an alpine buttercup. Oecologia 95: 187-193. DOI:

HEILMEIER H. & D. M. WHALE 1987: Carbon dioxide assimilation in the flowerhead of Arctium. Oecologia 73: 109-115. DOI:

HEW C. S., Y. W. Na, S. C. WoNG, H. H. YEOH & K. K. Ho 1984: Carbon dioxide fixation in orchid aerial roots. Physiol. Plant. 60: 154-158. DOI:

HOGAN K. P., M. B. GARCIA, J.M. CHEESEMAN & M. D. LOVELESS 1998: Inflorescence photosynthesis and investment in reproduction in the dioecious species Aciphylla glaucescens (Apiaceae). New Zeal. J. Bot. 36: 653-660. DOI:

MARCELIS L. F. M. & L. R. B. HoFMAN-EIJER 1995: The contribution of fruit photosynthesis to the carbon requirement of carbon requirement of cucumber fruits as affected by irradiance, temperature and ontogeny. Physiol. Plant. 93: 476-483. DOI:

NILSEN E.T. 1995: Stem photosynthesis extent, patterns and role in plant carbon economy. In: Gartner B. (ed.): Plant stems - Physiology and functional morphology. - Academic Press, San Diego, pp. 223-240. DOI:

PFANZ H. & G. ASCHAN 2001: The existence of bark and stem photosynthesis and its significance for the overall carbon gain. An eco-pysiological and ecological approach. Progress in Botany Vol. 62, Springer, Berlin-Heidelberg-New York, pp. 477-510. DOI:

PFANZ H., G. AscHAN, R. LANGENFELD-HEYSER, C. WITTMANN & M. LoosE 2002: Ecology and ecophysiology of tree stems - corticular and wood photosynthesis. Naturwissenschaften 89: 147-162. DOI:

PREBEG, T.; LJUBESIC, N. & M. WRISCHER 1999: Structural and physiological characteristics of the coloured tips of Leucojum petals. In: Vodnik, D. & Zel, J. (eds.) 2nd Slovenian Symposium on Plant Physiol., Univ. of Ljubljana, Slov. Gozd Martuljek, p. 62.

SALOPEK-SONDI B., M. KovAc, N. LJUBESIC & V. MAGNUS 2000: Fruit initiation in Helleborus niger L. triggers chloroplast formation and photosynthesis in the perianth. J. Plant Physiol. 157: 357-364. DOI:

SCHREIBER U., W. BILGER & C. NEUBAUER 1995: Chlorophyll fluorescence as a non-intrusive indicator for rapid assessment of in vivo photosynthesis. - In: Schulze E.D. & M.M. Caldwell (eds): Ecophysiology of photosynthesis, Vol. 100, Springer, Berlin, Heidelberg, New York, pp. 49-70. DOI:

SMILLIE R. M. 1992: Calvin cycle activity in fruit and the effect of heat stress. Sci. Hortic. 51: 83-95. Vu J. C. V., G. YELONSKY & M. G. HAUSHER 1985: Photosynthetic activity in the flower buds of ,,Valencia" orange (Citrus sinensis L. Osbeck). Plant Physiol. 78: 420---423. DOI:

WEISS D., M. SCHONFELD & A. H. HALEVY 1988: Photosynthetic activities in the Petunia corolla. Plant Physiol. 87: 666-670. DOI:

Zorz G. & P. Hrnrz 2001: The ecophysiology of vascular epiphytes: current knowledge, open questions. J. Exp. Bot. 52: 2067-2078. DOI:






Original Research Paper

How to Cite

Aschan, G., & Pfanz, H. (2003). Non-foliar photosynthesis and its contribution to the overall carbon balance of plants. Acta Biologica Slovenica, 46(2), 3-10.

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