Journal article
Legume phylogeny and the evolution of a unique contractile apparatus that regulates phloem transport
American journal of botany, Vol.97(5), pp.797-808
05/2010
Handle:
https://hdl.handle.net/2376/105004
PMID: 21622445
Abstract
Protein bodies called forisomes undergo Ca(2+)-dependent deformations to occlude sieve tubes reversibly, providing a unique regulatory mechanism of phloem transport. Because forisomes are known exclusively from the Papilionoideae (Leguminosae), the evolution of forisome function may have played a role in the rapid radiation of this huge taxon. The unexpected discovery of a papilionoid species lacking forisomes led us to evaluate a representative set of species covering 33 of the 36 legume tribes traditionally recognized. We found forisomes in Papilionoideae but not in Caesalpinioideae and Mimosoideae. Forisomes were absent from several species of the papilionoid tribe Galegeae. Forisomes with tail-like protrusions occurred less frequently than tailless ones; their distribution correlated with taxonomic units but not sharply enough to render forisome type a reliable criterion for classification. Thus, the distribution of forisome types appeared to reflect physiological variability in the pathways of forisome assembly rather than the evolution of forisome genes. On the other hand, Ca(2+)-dependent forisome deformation and sieve tube plugging occurred in Bobgunnia madagascariensis, a member of the swartzioid clade that presumably is the sister group of all other papilionoids, suggesting that forisomes and their unique mechanism of deformation are a synapomorphy of the Papilionoideae.
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Details
- Title
- Legume phylogeny and the evolution of a unique contractile apparatus that regulates phloem transport
- Creators
- Winfried S Peters - Indiana/Purdue University Fort Wayne, Department of Biology, 2101 East Coliseum Boulevard, Fort Wayne, Indiana 46805-1499 USADietmar HafferClaudia B HanakamAart J E van BelMichael Knoblauch
- Publication Details
- American journal of botany, Vol.97(5), pp.797-808
- Academic Unit
- Biological Sciences, School of
- Publisher
- United States
- Identifiers
- 99900546880501842
- Language
- English
- Resource Type
- Journal article