Colutea Research Articles

The Genus Colutea L.

The Genus Colutea L.

A SYNOPSIS OF THE GENUS COLUTEA (FABACEAE) IN IRAN

The genus Colutea (Fabaceae) has been revised in preparation for the Flora of Iran treatment and a synopsis is presented here. In Iran the genus includes four sections, three subsections and nine species. An identification key, notes and distributions are given for the taxa. Two new subsections are described: Colutea sect. Rostrata subsect. Gifana and Colutea sect. Rostrata subsect. Uniflora.

Colutea arborescens is nodulated by diverse rhizobia in Eastern Morocco

Eighteen isolates of rhizobia isolated from root nodules of Colutea arborescens (Bladder senna) grown in different soils of the eastern area of Morocco were characterized by phenotypic and genomic analyses. All the isolates characterized were fast growers. This is may be due to the isolation procedures used. The phenotypic, symbiotic and cultural characteristics analyzed allowed the description of a wide physiological diversity among tested isolates. The results obtained suggest that the phenotype of these rhizobia might have convergent evolved to adapt the local conditions. The genetic characterization consisted in an analysis of the rep-PCR fingerprints and the PCR-based RFLP of the 16S rDNA patterns. The 16S rDNA of six isolates representing the main ribotypes obtained by the PCR-based RFLP was sequenced. A large diversity was observed among these rhizobia, and they were classified as different species of the genera Rhizobium, Sinorhizobium and Mesorhizobium. The nodC gene was also sequenced, and the results confirmed the three lineages corresponding to the three genera. The results of the sequencing of nodC and 16S rDNA genes suggest that the nodulation genes and chromosome might have co-evolved among these bacteria.

Conservation of Colutea gifana, a rare and potential ornamental species, using in vitro method

In vitro methods provide a variety of tools to supplement traditional methods for collection, propagation and preservation of endangered plant species. In this study, an efficient protocol was developed for in vitro propagation of Colutea gifana, a rare and endangered plant species with limited reproductive capacity that grows in a narrow area of Iran. Single node explants were used for a series of experiments to select the appropriate disinfection method and growth regulators for establishment, proliferation and rooting stages. Explants showed the highest establishment percent after treatment with 2% Sodium hypochlorite (NaOCl) for 15 min, cultured in MS medium containing 2.2 μM 6-benzylaminopurine (BA) and 1 μM indole-3-butyric acid (IBA). In proliferation stage, 8.8 μM of BA was more effective cytokinin than Kinetin (Kin) and Thidiazuron (TDZ) for growth induction of axillary shoots. In vitro rooting of proliferated shoots was induced in halfstrength MS medium in all concentrations of both tested auxins i.e. IBA and α-naphthalene acetic acid (NAA). Eighty percent of the plantlets were successfully acclimatized to ex vitro conditions, showed normal development. These plants were used to replenish declining populations in the collection sites and conserve C. gifana from extinction.

Coluteol and Colutequinone B, More Antifungal Isoflavonoids from Colutea arborescens

The new antifungal compounds, coluteol (3',5'-dihydroxy-7,2',4'-trimethoxyisoflavan) and colutequinone B (7,4',6'-trimethoxyisoflavan-2',5'-quinone) have been isolated from the root bark of Colutea arborescens (common bladder senna) and identified by a combination of 1H- and 13C-NMR techniques.

Biosynthesis of the isoflavan isomucronulatol: Origin of the 2′,3′,4′-oxygenation pattern

Feeding experiments with 14C-labelled isoflavones in seedlings and pods of bladder senna ( Colutea arborescens) have demonstrated that 7-hydroxy-4′-methoxyisoflavone (formononetin), 7,3′-dihydroxy-4′-methoxyisoflavone (calycosin), 7,2′,3′-trihydroxy-4′-methoxyisoflavone (koparin) and 7,2′-dihydroxy-3′,4′-dimethoxyisoflavone are excellent precursors of (3 R)-isomucronulatol (7,2′-dihydroxy-3′,4′-dimethoxyisoflavan). 7,2′-Dihydroxy- 4′-methoxyisoflavone (2′-hydroxyformononetin) and 7-hydroxy-3′,4′-dimethoxyisoflavone (cladrin) were, however, poor substrates. Thus, the biosynthetic sequence to isomucronulatol from formononetin involves 3′-hydroxylation, 2′-hydroxylation and then 3′- O-methylation, followed presumably by stereospecific reduction of 7,2′-dihydroxy-3′,4′-dimethoxyisoflavone. Treatment of 2′,3′,4′-trimethoxyisoflavones with aluminium chloride in acetonitrile gives modest yields of 2′,3′-dihydroxy derivatives rather than 2′-monohydroxyisoflavones, and thus provides a convenient access to 2′,3′-dihydroxyisoflavones and related pterocarpans.

Observations of the Visits of Honey Bees and Bumble Bees to Bladder Senna (Colutea arborescens)2

The observations recorded herein were made on a few plants of bladder senna ( Colutea arborescens Lain.) grown experimentally in the forest nursery at Utah State University. This is a yellow-flowered, leguminous shrub introduced from Southern Europe or North Africa. It is grown as an ornamental or for a wind break in much the same manner as the more familiar Siberian pea bush ( Caragana arborescens Lam.). Its inflated pods distinguish it from the latter.