1021-4437/02/4906- $27.00 © 2002
Russian Journal of Plant Physiology, Vol. 49, No. 6, 2002, pp. 766–770. Translated from Fiziologiya Rastenii, Vol. 49, No. 6, 2002, pp. 859–864.
Original Russian Text Copyright © 2002 by Kosenko.
Various legume cultivars are well known to differ in
their capacity for the effective symbiosis with homolo-
gous root nodule bacteria. One of the causes for these
variations is a different degree of correspondence
between lectins of macro- and microsymbionts, which
determines the early stages of symbiosis development
and the efﬁciency of the symbiotic system as a whole
[1–3]. In this connection, a comparison between culti-
var-speciﬁc lectin properties is of considerable interest.
The evidence concerning broad-bean (
lectins, which are also termed favins, is extremely
scarce [4, 5]. As far as we know, cultivar-speciﬁc favin
properties have still not been investigated.
In this study, we compared the carbohydrate speci-
ﬁcity of lectins isolated from seeds of three broad bean
cultivars differing in their symbiotic response to inocu-
lation with effective nitrogen-ﬁxing strains of homolo-
gous root nodule bacteria . We attempted to reveal
possible differences in their afﬁnity for particular car-
MATERIALS AND METHODS
Lectins were isolated from seeds of three broad bean
L.) cultivars: Aushra, Daiva, and Yugeva,
which were obtained from the Latvian Research Insti-
tute of Agriculture, the Lithuanian Research Institute of
Agriculture, and the Estonian Research Institute of
Lectin puriﬁcation from other proteins was per-
formed using a Sephadex G-100 column chromatogra-
phy . Since favins are D-glucose/D-mannose-spe-
ciﬁc lectins [4, 5], they can be usually desorbed from
the column with 0.1 M D-glucose in 0.1 M acetate
buffer, pH 6.5–6.8. Such method for lectin elution was
successful in the case of lectins from cv. Aushra and
Daiva seeds, but not for cv. Yugeva lectins. In the last
case, we tried to elute lectins using 0.1 M solutions of
D-glucuronic and D-galacturonic acids, D-galactose, or
D-glucosamine–HCl in 0.1 M acetate buffer, pH 6.5–
6.8. The most effective eluent was D-glucosamine–
HCl. Two lectin preparations were isolated from cv.
Yugeva seeds: Yu-1, which was eluted from the column
with D-glucose; and Yu-2, which was eluted with D-
glucosamine–HCl. Only one lectin was isolated from
seeds of cv. Aushra, and another one was isolated from
seeds of cv. Daiva. The total amount of two lectins iso-
Cultivar-Specific Carbohydrate-Binding Properties of Lectins
from Broad-Bean Seeds
L. V. Kosenko
Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine,
ul. Zabolotnogo 154, Kiev, 03143 Ukraine;
fax: (38044) 266-2379; e-mail: firstname.lastname@example.org
Received October 21, 2001
—Lectins were isolated and puriﬁed from three broad bean (
L.) cultivars differing in the
effectiveness of their symbiosis with root nodule bacteria (
). From seeds
of symbiotically effective cvs. Aushra and Daiva, we isolated only one lectin from each cultivar, whereas two
lectins, Yu-1 and Yu-2, were isolated from seeds of symbiotically ineffective cv. Yugeva. Lectins from cvs.
Aushra and Daiva were more active than lectins from cv. Yugeva and exhibited similar carbohydrate speciﬁcity.
-D-mannopyranoside and trehalose were the most potent inhibitors of their hemagglutination activity.
Lectin Yu-1 resembled them in its carbohydrate-binding properties. However, D-mannose, trehalose, and
melecitose were its most effective inhibitors. Lectin Yu-2 differed substantially from these lectins. It exhibited
an afﬁnity for D-glucuronic acid, D-glucosamine, and 2-deoxy-D-glucose. In addition, it could interact with
carbohydrates of the galactose family (2-deoxy-D-galactose, D-galactosamine, and lactose) and also with D-
xylose and 2-deoxy-D-talose. Thus, lectins from cvs. Aushra and Daiva and also Yu-1 can be considered D-
mannose/D-glucose-speciﬁc lectins, whereas Yu-2 lectin exhibited a combined carbohydrate speciﬁcity. The
afﬁnity of Yu-1 and Yu-2 lectins for their natural receptors, exopolysaccharides and lipopolysaccharides of
broad-bean nodule bacteria, was twice as low as that of lectins from cvs. Aushra and Daiva. We believe that
properties of seed lectins are an important cultivar-speciﬁc trait that determines host-plant (broad beans) spec-
iﬁcity during the establishment of legume–rhizobia symbiosis.
Key words: Vicia faba - lectins - carbohydrate-binding properties - cultivar speciﬁcity
: MIC—the minimal inhibitory
concentration of the carbohydrate; Yu-1 and Yu-2—lectins from
cv. Yugeva seeds; SBL—soybean lectin.