Abstract
Two pea (Pisum sativum L.) hybrids differing in the presence or absence of the cyanide-resistant (alternative) pathway of respiration were constructed by reciprocally crossing cv. Alaska and cv. Progress No. 9. The F1 hybrids were grown in greenhouses maintained at either 350 or 650 ppm CO2, and the growth, flowering, and dry matter accumulation were compared. The objective was to assess the significance of the alternative respiratory pathway to whole-plant carbon budgets and further to test the hypothesis that the alternative pathway is important in oxidizing excess carbohydrates such as might accumulate under conditions of CO2 enrichment. More carbohydrates were available in the F1 hybrid lacking the pathway, as evidenced by greater plant height, leaf area, specific leaf weight, and total dry matter compared with the reciprocal hybrid, especially at 650 ppm CO2. Specific leaf weight increased markedly under CO2 enrichment in the hybrid lacking the pathway, while it was the same at 350 and 650 ppm in the reciprocal cross. The hybrid lacking the alternative pathway also outperformed the reciprocal cross in terms of total dry matter and seed production. Increased branching with CO2 enrichment was observed in the hybrid lacking the pathway, while branching in the reciprocal cross was only slightly stimulated. These results suggest that alternative respiration consumes luxury carbohydrate and that respiration via this pathway may be considered energetically wasteful in terms of whole-plant carbon budgets.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Azcón-Bieto J., Lambers H., Day D. A. Effect of photosynthesis and carbohydrate status on respiratory rates and the involvement of the alternative pathway in leaf respiration. Plant Physiol. 1983 Jul;72(3):598–603. doi: 10.1104/pp.72.3.598. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bahr J. T., Bonner W. D., Jr Cyanide-insensitive respiration. I. The steady states of skunk cabbage spadix and bean hypocotyl mitochondria. J Biol Chem. 1973 May 25;248(10):3441–3445. [PubMed] [Google Scholar]
- Day D. A., Arron G. P., Christoffersen R. E., Laties G. G. Effect of ethylene and carbon dioxide on potato metabolism: stimulation of tuber and mitochondrial respiration, and inducement of the alternative path. Plant Physiol. 1978 Nov;62(5):820–825. doi: 10.1104/pp.62.5.820. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GREGORY F. G., VEALE J. A. A reassessment of the problem of apical dominance. Symp Soc Exp Biol. 1957;11:1–20. [PubMed] [Google Scholar]