Abstract
Photosynthetic responses to irradiance by the grey mangrove, Avicennia marina (Forstk.) Vierh var. australasica (Walp.) Moldenke, were studied using seedlings grown under natural understory shade and exposed conditions as well as in the laboratory under high and low light regimes, i.e. 100% and 6% sunlight, respectively. Leaves in exposed locations were subjected to daylight quantum flux densities greater than 1,000 microeinsteins per square meter per second from 0900 to 1700 hours, whereas those in understory shade experienced only 30 to 120 microeinsteins per square meter per second, interrupted for brief periods by sunflecks ranging in quantum flux density from 800 to 1,500 microeinsteins per square meter per second. The low light regime was similar in light intensity to that of the understory environment, but lacked sunflecks.
Leaves from the understory environment showed several properties of `shade' leaves; i.e. they contained more chlorophyll on both a leaf area and fresh weight basis but had a lower specific weight and greater area than exposed leaves, and were enriched in chlorophyll b relative to a. However, there were no significant differences in either the gas exchange or leaf chlorophyll fluorescence characteristics of the two populations, both being typical of `sun' leaves.
Leaves grown in the laboratory under low and high light regimes had similar properties. However, light saturated assimilation rates in the leaves from the low light treatment were 20% less and became light saturated at a lower quantum flux density than those of leaves grown under the high light regime. The ecological significance of these results is discussed.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anderson J. M., Goodchild D. J., Boardman N. K. Composition of the photosystems and chloroplast structure in extreme shade plants. Biochim Biophys Acta. 1973 Dec 14;325(3):573–585. doi: 10.1016/0005-2728(73)90217-x. [DOI] [PubMed] [Google Scholar]
- Arnon D. I. COPPER ENZYMES IN ISOLATED CHLOROPLASTS. POLYPHENOLOXIDASE IN BETA VULGARIS. Plant Physiol. 1949 Jan;24(1):1–15. doi: 10.1104/pp.24.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burnside C. A., Böhning R. H. The Effect of Prolonged Shading on the Light Saturation Curves of Apparent Photosynthesis in Sun Plants. Plant Physiol. 1957 Jan;32(1):61–63. doi: 10.1104/pp.32.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ehleringer J., Björkman O. Quantum Yields for CO(2) Uptake in C(3) and C(4) Plants: Dependence on Temperature, CO(2), and O(2) Concentration. Plant Physiol. 1977 Jan;59(1):86–90. doi: 10.1104/pp.59.1.86. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nobel P. S. Photosynthetic Rates of Sun versus Shade Leaves of Hyptis emoryi Torr. Plant Physiol. 1976 Aug;58(2):218–223. doi: 10.1104/pp.58.2.218. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nobel P. S., Zaragoza L. J., Smith W. K. Relation between Mesophyll Surface Area, Photosynthetic Rate, and Illumination Level during Development for Leaves of Plectranthus parviflorus Henckel. Plant Physiol. 1975 Jun;55(6):1067–1070. doi: 10.1104/pp.55.6.1067. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Powles S. B., Critchley C. Effect of Light Intensity during Growth on Photoinhibition of Intact Attached Bean Leaflets. Plant Physiol. 1980 Jun;65(6):1181–1187. doi: 10.1104/pp.65.6.1181. [DOI] [PMC free article] [PubMed] [Google Scholar]