Plant Physiol. email content delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Plant Physiology 71:122-127 (1983)
© 1983 American Society of Plant Biologists

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rainbird, R. M.
Right arrow Articles by Sanford, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rainbird, R. M.
Right arrow Articles by Sanford, P.
Agricola
Right arrow Articles by Rainbird, R. M.
Right arrow Articles by Sanford, P.
Articles

Significance of Hydrogen Evolution in the Carbon and Nitrogen Economy of Nodulated Cowpea 1

Ross M. Rainbird2, Craig A. Atkins, John S. Pate and Paul Sanford

Department of Botany, University of Western Australia, Nedlands 6009, Australia

The carbon and nitrogen economies of a single cultivar of cowpea (Vigna unguiculata (L.) Walp.cv Caloona) nodulated with either a high H2-evolving strain (176A27) or a low H2-evolving strain (CB756) of Rhizobium were compared. The two symbioses did not differ in total dry matter production, seed yield, nitrogen fixed, the spectrum of nitrogenous solutes produced by nodules for export, or the partitioning of net photosynthate within the plant throughout the growth cycle. Detailed examination of the carbon and nitrogen economy of the nodules, however, showed a significant difference between the symbioses. Nodules formed with CB756 lost less CO2 in respiration compared to the higher H2-evolving symbioses and this could have been largely responsible for a 36% better economy of carbon use in CB756 nodules during the period of maximum H2 evolution (48-76 days) and over the whole growth period (20-90 days), a 16% economy. In terms of overall net photosynthate generated by the plant, these economies were equivalent to 5% and 2% of the carbon utilized in the two periods, respectively. From the differences in H2 evolution and CO2 production by nodules of the two symbioses, the cost of H2 evolution was found to be 3.83±0.6 millimoles CO2/millimoles H2 for plants grown in sand culture and 1.69 ± 0.48 millimoles CO2/millimoles H2 for those in water culture. In both symbioses, the ratio of H2 evolution to N2 fixed varied markedly during ontogeny, indicating a significant variation in the relative efficiency and thus metabolic cost of N2 fixation at different stages during development.

2 Present address: Du Pont Experimental Station, Central Research and Development Department, Wilmington, Delaware 19898.

1 Supported by funds from the General Development Grant of the University of Western Australia and the Wheat Industry Research Council of Australia.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY THE PLANT CELL
Copyright © 1983 by the American Society of Plant Biologists