Am. J. Bot. Visit Plant Cell Online
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
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 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 Google Scholar
Google Scholar
Right arrow Articles by Randle, C. P.
Right arrow Articles by Wolfe, A. D.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Randle, C. P.
Right arrow Articles by Wolfe, A. D.
Agricola
Right arrow Articles by Randle, C. P.
Right arrow Articles by Wolfe, A. D.
(American Journal of Botany. 2005;92:1575-1585.)
© 2005 Botanical Society of America, Inc.

Systematics and Phytogeography

The evolution and expression of RBCL in holoparasitic sister-genera Harveya and Hyobanche (Orobanchaceae)1

Christopher P. Randle2,4 and Andrea D. Wolfe3

2Department of Ecology and Evolutionary Biology and the Natural History Museum, University of Kansas, 1200 Sunnyside Ave., Lawrence, Kansas 66045 USA; 3Department of Evolution, Ecology and Organismal Biology, Ohio State University, 318 W. 12th Ave., Columbus, Ohio 43210 USA

The evolution of holoparasitism decreases the adaptive value of genes maintaining the photosynthetic apparatus. These may become pseudogenes through insertion or deletion events resulting in frameshift mutations, or by the evolution of premature stop codons. The holoparasitic sister genera Harveya and Hyobanche have undergone alternate pathways of evolution and expression at the plastid locus rbcL. An open reading frame in all but a single species of Harveya is maintained by purifying selection and is expressed. However, the function of Rubisco in this putative holoparasite is unknown. Conversely, Hyobanche has undergone rbcL pseudogene formation, and comparison of synonymous and nonsynonymous rates of evolution indicates that selection has not played a role in its evolution. This is complicated by the following findings: multiple pseudogene copies of rbcL exist in tissues of Hyobanche, rbcL transcripts also encode pseudogenes, and the large subunit is present in some tissues of Hyobanche. We hypothesize that the rbcL operon is in a state of degradation as may be expected in a holoparasite and is not endogenously expressed. Rather, the large subunit may be taken up from the host plants, and accumulate in tissues as a result of transpiration.

Key Words: Harveya • Hyobanche • Orobanchaceae • parasitic plant • rbcL • Rubisco • South Africa






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2005 by the Botanical Society of America, Inc.