Cladistic analysis of phylogenetic relationships among tribes Cicereae, Trifolieae, and Vicieae (Leguminosae)

A cladistic analysis of tribes Cicereae, Trifolieae, and Vicieae was carried out using 33 morphological, anatomical, karyological, and chemotaxonomical characteristics. Transformation polarities of the character states were developed by comparison with the character states of the genus Galega, the sister group of the tribes. Cicereae and Vicieae were found to be a monophyletic group, and Trifolieae was its sister group. The seven synapomorphic characters of Cicereae and Vicieae were presumed to be: germination hypogeal vs. epigeal; first leaf in seedlings scarious vs. laminous; leaves paripinnately and tendrilous vs. imparipinnately and etendrilous; postchalazal vascular bundle present in seed coats vs. absent; a cotyledon flap present at antihilar side vs. absent; radicles short in seeds vs. long; and plumules long in seeds vs. short.     

Phytoalexin induction and its chemosystematic significance in the genus Trigonella

Using the drop-diffusate technique, a number of isoflavonoid phytoalexins have been obtained from the excised, fungus-inoculated leaflets of 41 species belonging to the legume genus Trigonella. Leaf diffusates variously contained pterocarpan (medicarpin and maackiain) and isoflavan (vestitol and sativan) derivatives previously associated with genera closely allied to Trigonella. In diffusates from T. calliceras, medicarpin was accompanied by a phytoalexin (designated TC-1) provisionally identified as a new hydroxylated pterocarpan. Most of the Trigonella species were also examined for their ability to release coumarin upon tissue maceration. The combined phytoalexin/coumarin data suggest that three major intrageneric chemical divisions occur in Trigonella; two of these apparently link the genus to Medicado/Factorovskya and Melilotus respectively, whilst the third provides some evidence for a connection with Trifolium. The taxonomic aspects of these findings are discussed in the light of earlier morphological studies which provided evidence for a distinct floral dichotomy amongst Trigonella species.     

Trifolieae and related seeds from archaeological contexts: problems in identification

Small legume seeds are commonly recovered from Epipalaeolithic and Early Neolithic sites in north Africa and south-west Asia, often as a high proportion of the total plant remains. Their role is uncertain, but it is thought that small-seeded legumes may once have been a human food resource. They are difficult to identify. The gross morphology and testa surface micromorphology have been investigated in fresh seeds of members of the tribe Trifolieae and some related tribes in the same subfamily Faboideae. The separation of the four genera Medicago, Melilotus, Trifolium, and Trigonella has been attempted by multivariate analysis of seed characters that can be seen in experimentally charred seed specimens. The characters used have also been observed in well-preserved ancient charred small legume seeds, and so can be readily used for the purpose of identification. Although identification to the level of species is rarely possible, identification to generic level could provide information useful for the interpretation of this category of ancient plant remains.     

An isocoumarin and other phenolic components of Ononis natrix

From the n-hexane extract of the whole aerial part of flowering Ononis natrix, besides homopterocarpin and some known terpenoids and sterols, three new compounds: 8-hydroxy-6-methoxy-3-undecyl-3,4-dihydroisocoumarin, 5-(2-acetoxytridecyl)-3-methoxyphenol and 5-(2-hydroxytridecyl)-3-methoxyphenol have been isolated.     

Homoglutathione: isolation, quantification and occurrence in legumes

Homoglutathione (hGSH: γ-glutamyl-eysteinyl-β-alanine) was purified from seeds of Phaseolus coccineus L. cv. Preisgewinner, using anion-exchange chromatography and Cu₂O precipitation. Quantitative and specific determination of this thiol is possible by high-performance liquid chromatography (HPLC) after monobromobimane derivatization. The enzymatic recycling assay based on yeast glutathione reductase (EC 1.6.4.2) can also be applied, but only to samples containing either hGSH or glutathione (GSH), since enzyme reaction with hGSH is 2.7 times faster than with GSH. Using the very sensitive HPLC method, the thiol content of leaves, roots and seeds of several legumes was investigated. Although GSH and hGSH were found in all plants analysed, the GSH/hGSH ratio varied greatly within the different tribes as well as within the different organs of plants of one species. In seeds and leaves of Vicieae, only traces of hGSH were found beside the main thiol GSH, whereas in roots the hGSH content exceeded the GSH content. The Trifolieae contained both tripeptides and in the tribe Phaseoleae, hGSH predominated by far.     

The delimitation of the tribe Vicieae (Leguminosae) and the relationships of Cicer L.

A survey of morphological, anatomical, karyological and chemical characters has been carried out, centred on the Vicieae but extending to the neighbouring tribes Trifolieae and Ononideae. The results show that Cicer , traditionally a member of the Vicieae, has more in common with genera of the Trifolieae and Ononideae than with the rest of the Vicieae. It is proposed that Cicer should be removed from the Vicieae and recognized as the monogeneric tribe Cicereae Alef. The tribe Vicieae sensu stricto, a well-defined natural group, is delimited and described. Phylogenetic relationships of the Cicereae are discussed.     

Immunochemical behaviour of legumin and vicilin from Vicia faba: a survey of related Proteins in the leguminosae subfamily faboideae

An antiserum specific for the legumin and vicilin of Vicia faba was used to examine extracts of seeds of taxa of the Fabeae and Trifolieae for the presence of related storage proteins, Proteins related to legumin were found to be widely distributed, indicating considerable conservation of the genetic information for this protein. Only Pisum sativum contained a protein immunochemically identical with the vicilin of V. faba; the equivalent proteins of all other genera tested here were immunochemically different from vicilin.     

Fungal modification of pterocarpan phytoalexins from Melilotus alba and Trifolium pratense

Medicarpin (3-hydroxy-9-methoxypterocarpan), an isoflavonoid phytoalexin characteristic of sweetclover (Melilotus alba), is metabolised by three fungi, Botrytis cinerea, Colletotrichum lindemuthianum (race β) and C. coffeanum (isolates CCA and CCP) to afford products with decreased antifungal activity. Peterocarpan phytoalexins from red clover (Trifolium pratense) are similarly modified. A fourth organism, Helminthosporium carbonum apparently lacks this ability. Fungal-mediated tranformation principally involves hydroxylation, methylation and demethylation although ring fission has also been noted.