全 文 ：Received 5 Aug. 2003 Accepted 2 Jan. 2004
Supported by the Hi-Tech Research and Development (863) Program of China (2001AA212091) and the National Special Program for
Research and Industrialization of Transgenic Plants (J99-A-007).
* Author for correspondence. Tel: +86 (0)21 65642772; E-mail: .
http://www.chineseplantscience.com
Acta Botanica Sinica
植 物 学 报 2004, 46 (7): 767-772
.Rapid Communication.
Transgenic Tobacco Expressing Lycoris radiata Agglutinin Showed
Enhanced Resistance to Aphids
PANG Yong-Zhen1, YAO Jian-Hong1, SHEN Guo-An2, QI Hua-Xiong3, TAN Feng4,
SUN Xiao-Fen1, TANG Ke-Xuan 1, 2*
(1. State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan-SJTU-Nottingham Plant Biotechnology
R & D Center, Fudan University, Shanghai 200433, China;
2. Plant Biotechnology Research Center, School of Agriculture and Biology, Fudan-SJTU-Nottingham Plant
Biotechnology R & D Center, Shanghai Jiaotong University, Shanghai 200030, China;
3. Hybrid Rice Research Center, Hubei Academy of Agricultural Sciences, Wuhan 430064, China;
4. Faculty of Life Sciences, Southwest Normal University, Chongqing 400715, China)
Key words: insect bioassay; Lycoris radiata agglutinin (LRA); transgenic tobacco; peach potato aphid
(Myzus persicae)
Transgenic plants expressing foreign genes resulting in
resistance against pests could make significant contribu-
tion to sustainable agriculture. Considerable progress has
been achieved to control the chewing insect pests by the
development of transgenic plants expressing Bacillus
thuringiensis endotoxins (Barton and Miller, 1993) or plant-
derived proteins such as protease inhibitor (Hoffman et al.,
1992; Hilder et al., 1993) or lectins (Boulter et al., 1990).
However, there are fewer reports on the successful control
of sap-sucking insects belonging to the order Homoptera
by the use of genetic engineering technology. The sap-
sucking insects have piercing and sucking mouth-parts and
feed upon sap of the plants and most of them are serious
pests of agricultural and horticultural crops including aphids
(Aphididae), whiteflies (Aleyrodidae), planthoppers
(Delphacidae) and leafhoppers (Cicadellidae). Crop is de-
stroyed not only by pest feeding, but also by plant viruses
produced through lesions that the mouthparts made.
In the past few years, a number of plant lectin genes
have been cloned, among which lectins from Amaryllidaceae
species were most extensively studied and well documented
(van Damme et al., 1991a; 1991b; 1992; 1998; Rahbe et al.,
1995; Gatehouse et al., 1996). Lectins from different spe-
cies of family Amaryllidaceae showed extensive similarity
in both structures and functions (van Damme et al., 1992).
Recent studies showed that some plant lectins from
Amaryllidaceae species were toxic to sap-sucking insects
in artificial diet assay (Powell et al., 1993; 1995), among
which the lectin (GNA) from snowdrop (Galanthus nivalis)
was the most toxic. Transgenic tobacco and rice express-
ing GNA showed significant insecticidal activity towards
the peach potato aphids (Myzus persicae) (Hilder et al.,
1995) and rice brown planthopper (BPH, Nilaparvata
lugens) respectively in bioassay and feeding tests (Rao et
al., 1998). Interestingly, up to now, most of the lectin genes
cloned from species of Amaryllidaceae such as G. nivalis,
Narcissus pseudonarcissus and Hippeastrum showed more
or less toxicity towards sap-sucking insects, including
aphids and planthoppers, in artificial diet assays (Powell et
al., 1995).
Recently, a lectin gene from Lycoris radiata has been
cloned from our laboratory (GenBank accession number
AY191306) (Yao et al., 2001). The homology analysis
showed that the amino acid sequence of (Lycoris radiata
agglutinin) (LRA) is 72% identical to that of G. nivalis ag-
glutinin (Genbank accession number AAA33346) and the
nucleic acid sequence of lra is 81% identical to that of G.
nivalis agglutinin (GenBank accession number M55556).
As Lycoris radiata also belongs to Amaryllidaceae and its
lectin shares high similarity to GNA, it is speculated that
LRA may also have a similar inhibitory effect on sap-suck-
ing insects like other lectins such as GNA from
Amaryllidaceae and may play a role in controlling sap-suck-
ing insects by genetic engineering. Up to now, there is no
report on the genetic transformation and generation of
transgenic plants containing the lra gene, which is a pre-
requisite for testing the insect resistance effect of LRA in
whole plant. In the present paper, we report the generation
Acta Botanica Sinica 植物学报 Vol.46 No.7 2004768
of transgenic tobacco plants containing and expressing
LRA. The aphid bioassay test on transgenic tobacco is
also presented.
1 Materials and Methods
1.1 Plasmid construction
The lra gene was cloned from leaves of Lycoris radiata
(L’Her）Herb. using RACE-PCR protocol (Yao et al., 2001)
and inserted into pGEM T-Easy Vector (Promega, USA).
The resulting plasmid TELRA was digested with NotⅠ and
inserted into the NotⅠ -pre-digested pKS to generate
pKSLRA. The plasmid pKSLRA was then digested with
BamHⅠ and SacⅠ to release a fragment containing the
coding sequence of the lra (477 bp) and the latter was
inserted into Agrobacterium binary vector pBI121 pre-di-
gested with BamHⅠ and SacⅠ to generate pBILRA. The
recombinant plasmid, pBILRA, contained the selectable
marker neomycin phosphotransferase gene (nptⅡ) confer-
ring kanamycin resistance and the lra, both driven by the
cauliflower mosaic virus 35S promoter (CaMV35S). pBILRA
was transferred from Escherichia coli DH5a into
Agrobacterium tumefaciens EHA105 by triparental mating
(Holsters et al., 1978) and was used to transform tobacco.
1.2 Transformation and regeneration of transgenic to-
bacco plants
The tobacco (Nicotiana tabacum L.) cultivar “Geshi 1”
was used for transformation. The transformation was per-
formed essentially as described by Horsch et al. (1988). A.
tumefaciens strain EHA105 containing pBILRA was grown
for 2 d at 28 ℃ in Luria Broth medium supplemented with 50
mg/L kanamycin, 50 mg/L rifampicin and 50 mg/L
streptomycin. The bacteria were collected and suspended
at a density of 1× 109 in hormone-free half-strength MS
(Murashige and Skoog, 1962) liquid medium before use.
The leaf discs of approximately 0.5-1.0 cm2 were immersed
in the bacterial suspension for 5 min, transferred onto hor-
mone-free MS medium solidified with 2.6 g/L phytagel
(Sigma, USA) and incubated at 26 ℃ in the dark for 2 d.
After the co-cultivation, the discs were placed on selection
medium (MS basal medium supplemented with 1.0 mg/L
BA, 0.1 mg/L NAA, 50 mg/L kanamycin and 250 mg/L
carbenicillin) and cultured for three weeks at 26 ℃ under a
12-h light/12-h dark photoperiod (50 µmol.m-2 .s-1 light
intensity provided by white fluorescent tubes) until shoots
developed. The regenerated green healthy shoots were
separated from the explants and transferred to hormone-
free MS medium containing 50 mg/L kanamycin for rooting.
The well-rooted plants were eventually transferred to soil
in pots in greenhouse.
1.3 PCR and Western blotting analyses
Putative transformants and the control (non-
transformant) plant were used for PCR analysis. Plant DNA
was extracted from young leaves using the protocol of
Edwards et al. (1991). PCR analysis for the detection of the
lra gene was carried out using the forward primer SSF1
s t a r t i n g f r o m t h e s t a r t c o d o n ( 5 -
ATGGCTAAGCCAAGTTTCCTC-3 ) and the reverse primer
SSR1 including 8 bp downstream of stop codon (5-
ACCGGTCATTACTTGTTGGTC-3). The expected product
size was 485 bp (shown in Fig.1). The PCR reactions were
carried out in a total volume of 25 mL comprising 50 ng
tobacco genomic DNA, 50 mmol/L KCl, 10 mmol/L Tris-HCl
(pH 8.3), 1.5 mmol/L MgCl2, 200 mmol/L dNTPs, 1.25 units
of Taq DNA polymerase and 25 pmol of each primer. For
PCR analysis, DNA was denatured at 94 ℃ for 5 min fol-
lowed by 35 cycles of amplification (94 ℃ for 30 s, 56 ℃ for
50 s, 72 ℃ for 1 min) and by 10 min at 72 ℃.
Nineteen independently derived transgenic tobacco
lines were also analyzed for LRA expression by Western
blot. Due to the high similarity between LRA and GNA,
polyclonal rabbit anti-GNA antiserum (Pestax, UK) was used
as the primary antiboby in the Western blotting analysis
for LRA expression in transgenic plants. Protein was ex-
tracted from young leaves by grinding in 100 µL phosphate
buffered saline buffer (PBS, pH 7.2) at 4 ℃. Following cen-
trifugation at 2 000g for 10 min at 4 ℃, supernatants were
transferred into fresh tubes and total protein from each
sample was quantified by using the Bradford assay
(Bradford, 1976). Bradford regent (Amresco, USA) was used
to quantify the protein samples according to the
Fig.1. Representative PCR analysis for the presence of the
Lycoris radiata agglutinin (lra) gene in transgenic tobacco plants.
Lanes 1-7, independent transgenic plants; M, size marker
(DL2000); N, untransformed plant (negative control); P, pBILRA
(positive control). The arrow indicates the expected PCR prod-
uct (485 bp).
PANG Yong-Zhen et al.: Transgenic Tobacco Expressing Lycoris radiata Agglutinin Showed Enhanced Resistance to Aphids 769
manufacture’s introduction. Aliquots of 30 µg total soluble
protein per sample were loaded and fractionated on a 15%
SDS-polyacrylamide gel and blotted to a nitrocellulose
membrane. The protocols for the Western blot were carried
out according to the manuscript’s introduction (Pestax,
UK). Subsequently, levels of LRA protein were measured
by scanning densitometry using purified GNA protein (100
ng) as a reference.
1.4 Aphid bioassay test
Three independently derived transgenic tobacco T0
lines expressing different levels of LRA (plant numbers 2, 5
and 6, three cloned replicate plants per line), together with
untransformed tobacco controls, were challenged by peach
potato aphids (M. persicae Sulzer) and investigated for
their effects on aphid survival and the development of aphid
population using a protocol essentially the same as de-
scribed by Hilder et al. (1995). The aphid bioassay test was
carried out at Crop Protection Institute of Hubei Academy
of Agricultural Sciences in China. Each plant (20-30 cm
tall) was confined to an insect-proof fine-mesh nylon cage,
10 late (third) instar aphid nymphs were introduced with a
hair brush to tobacco leaves of each plant on day 0 and the
insect survival and growth of the insect populations were
measured at 2 d intervals for a 20 d period. The experiment
was repeated three times (each independently derived
transgenic line was micropropagated into three cloned
plants).
1.5 Genetic analysis of segregation of lra gene in T1
progenies
Seven independent T0 primary transgenic plants (plant
numbers 1, 2, 3, 4, 5, 6 and 7) were grown to maturity. T1
seeds were harvested and sown in soil in the greenhouse.
The germinated T1 plants were analyzed for the presence
of the lra gene by PCR for the segregation patterns.
2 Results and Discussion
2.1 Selection, plant regeneration and molecular analysis
of transgenic plants
After three weeks of selection with 50 mg/L kanamycin,
a total of 32 independent kanamycin-resistant plants were
recovered. PCR analysis revealed that 25 out of 32 plants
were positive for the presence of the lra gene, indicating
that the lra gene had integrated into the plant genome
(Fig.1).
Nineteen independent lra-PCR positive plants were fur-
ther analyzed by Western blot for LRA expression. The
result showed that 17 out of 19 plants (90%) expressed
LRA and the expression levels varied from 0.01%-1.00% of
total soluble protein. From the representative Western blot
result (Fig.2), it could be measured that plant numbers 2, 3,
5 and 7 expressed LRA of approximately 0.1%-0.2% of to-
tal soluble protein while plant No. 1 expressed LRA of less
than 0.1% of total soluble protein. The highest LRA (over
0.7% of total soluble protein) expression was found in plant
numbers 4 and 6. The band size of LRA was similar to that
of GNA (Fig.2).
2.2 Aphid bioassay test
The results of aphid bioassay revealed that all the three
independent lines (numbers 2, 5 and 6) showed more or
less enhanced resistance and inhibition to aphid popula-
tion and the mean number of aphids on these plants was
less than that on the control plants at the end of the assay
period (Fig.3). However, although aphid population on the
transgenic line numbers 2 and 5 was lower than that on the
control plants during most of the assay period, aphid popu-
lation started to grow up from day 10 and no significant
Fig.3. Aphid bioassay tests on transgenic tobacco line numbers
2, 5 and 6. Points and bars indicate mean ± SE. Ten late instar
aphid nymphs were introduced into each plant on day 0 and the
insect survival and growth of aphid population were measured at
2 d intervals for 20 d period. Differences between transgenic lines
No. 6 with the control were significant at P < 0.05 constantly
from day 6 to day 20 throughout the assay period.
Fig.2. Representative Western blotting analysis for the expres-
sion of the Lycoris radiata agglutinin (lra) gene in transgenic
tobacco plants. Protein was extracted from young leaves and 30
µg was loaded in each lane. Lanes 1-7, independent transgenic
plants; N, untransformed plant (negative control); P, 100 ng pu-
rified GNA protein (positive control, 12 kD).
Acta Botanica Sinica 植物学报 Vol.46 No.7 2004770
difference (P < 0.05) for aphid number could be found be-
tween transgenic lines (numbers 2 and 5) and the control
line. The situation was different for transgenic line No. 6
with high LRA expression (over 0.7%) on which the mean
number of aphids was significantly less than that on the
control plants constantly from day 6 to day 20 throughout
the assay period with the significant differences at P < 0.05.
The results also indicated that transgenic plants with higher
levels of LRA expression had stronger resistance to aphids
and inhibition to the growth of aphid population.
2.3 Genetic analysis of segregation of the lra gene in T1
progenies
T1 progenies of the seven independently derived pri-
mary transformants were analyzed for the presence of the
lra gene by PCR. Results showed that the lra gene in six
out of the seven lines analyzed, except for line No. 3, as
inherited at a segregation ratio of 3:1, indicating the inte-
gration of the lra transgene into a single genetic locus of
tobacco genome (Table 1).
Earlier feeding trials with purified plant lectins showed
that some lectins had chronic detrimental effects on the
survival of certain insects (Shukle and Murdock, 1983;
Rahbe et al., 1995). The development of transgenic plants
expressing a lectin (glucose/mannose-binding lectin) from
pea with enhanced resistance to insect pests was first re-
ported in 1990 (Boulter et al., 1990). The lectin gene from
snowdrop (Galanthus nivalis agglutinin, GNA) was the
first cloned gene to be demonstrated to confer enhanced
resistance to a wide range of sap-sucking insect pests in-
cluding aphids (Hilder et al., 1995; Gatehouse et al., 1996)
and planthoppers (Rao et al., 1998; Foissac et al., 2000).
Previous studies showed that many other mannose-bind-
ing lectins from the monocotyledonous family
Amaryllidaceae had more or less insecticidal activities in
feeding experiments with both native proteins and
transgenic plants (Powell et al., 1993; Hilder et al., 1995;
Rao et al., 1998). In addition to anti-pest properties, recent
studies showed that some mannose-binding lectins from
monocotyledonous species such as gastrodianin from
Orchidaceae also had antifungal properties (Wang et al.,
2001). The isolation and utilization of novel sap-sucking
insect resistance genes are required to provide pyramiding
strategies for enhancing and lasting resistance to the pests.
In the present study, we generated transgenic tobacco
plants containing and expressing the lra gene. Western
blotting analysis revealed that most of the transgenic plants
tested expressed the lra gene at various levels. A similar
phenomenon was also evident for majority of transgenic
plants containing other lectin genes such as the gna gene
in respect to the transgene expression (Tang et al., 1999).
When used in the whole plant bioassay for the resistance
against peach potato aphids (M. persicae), the transgenic
plants expressing LRA at levels of 0.1%-0.2% did show
enhanced inhibition to the growth of aphid population.
However, the level of enhanced resistance to aphids was
not significant at the end of assay period compared with
that for the control plants. The growth of aphid population
was significantly inhibited on the transgenic line with stron-
ger LRA expression (over 0.7%), compared with that on the
control plants. The aphid resistance levels of transgenic
plants were directly proportional to the levels of LRA
expression, revealed by Western blotting analysis, indicat-
ing the resistance of transgenic tobacco plants to peach
potato aphids was conferred by the expression of lra gene
in the plants. A very similar result was also obtained from
aphid bioassay on transgenic tobacco plants expressing
high levels of GNA when challenged by peach potato aphids
in an earlier study (Hilder et al., 1995). Segregation analysis
of T1 progenies indicated that the lra gene from most of
the independent transgenic lines was inherited into T1 prog-
enies as a single Mendelian trait, which was commonly
observed in the transgene segragation studies (Rao et al.,
1998; Bano-Maqbool and Christou, 1999; Tang et al.,
2001).
The present study shows that in small-scale trials car-
ried out under controlled environment conditions,
Table 1 Segregation analysis of Lycoris radiata agglutinin (lra) gene in T1 progenies of transgenic tobacco lines
T1 line Total assayed Expected ratio
PCR for lra gene
lra+ lra- c2 P
No. 1 30 3:1 20 10 1.11 0.29
No. 2 30 3:1 24 6 0.40 0.53
No. 3 30 3:1 16 14 7.51 0.01
No. 4 30 3:1 20 10 1.11 0.29
No. 5 30 3:1 22 8 0.04 0.83
No. 6 30 3:1 18 12 3.60 0.06
No. 7 30 3:1 23 7 0.04 0.83
Four-week-old T1 progeny plants were analyzed by PCR for the presence of the lra gene.
PANG Yong-Zhen et al.: Transgenic Tobacco Expressing Lycoris radiata Agglutinin Showed Enhanced Resistance to Aphids 771
expression of LRA in transgenic tobacco plants affords
enhanced levels of protection against the aphid, one of the
most serious insect pests causing significant yield losses
of crops. The lra gene thus represents a promising
candidate, as a supplement to the gna gene, to be used in
genetic engineering for enhanced insect resistance and may
make a valuable contribution to crop protection. Further
work will be focused on the reconstruction of transforming
vectors containing the lra gene driven by a stronger pro-
moter which would deliver higher expression of LRA, con-
sequently giving the transgenic plants with higher levels
of resistance to aphids.
References:
Bano-Maqbool S, Christou P. 1999. Multiple traits of agronomic
importance in transgenic indica rice plants: analysis of
transgene integration patterns, expression levels and
stability. Mol Breeding, 5: 471-480.
Barton K A, Miller M J. 1993. Transgenic Plants. New York:
Academic Press. 297-315.
Boulter D, Edwards G A, Gatehouse A M R, Gatehouse J A,
Hilder V A. 1990. Additive protective effects of different
plants-derived insect resistance genes on transgenic tobacco
plants. Crop Prot, 9: 351-354.
Bradford M M. 1976. A rapid and sensitive method for the
quantitation of microgram quantities of protein utilizing
the principle of protein-dye binding. Anal Biochem, 72:
248-254.
Edwards K, Johmstone C, Thompson C. 1991. A simple and
rapid method for the preparation of plant genomic DNA
for PCR analyses. Nucleic Acids Res, 98: 1349.
Foissac F, Loc N T, Christou P, Gatehouse A M R, Gatehouse J
A. 2000. Resistance to green leafhopper (Nephotettix
virescens) and brown planthopper (Nilaparvata lugens)
in transgenic rice expressing snowdrop lectin (Galanthus
nivalis agglutinin; GNA). J Insect Physiol, 46: 573-583.
Gatehouse A M R, Down R E, Powell K S, Sauvion N, Rahbe Y,
Newell C A, Merryweather A, Hamilton W D O, Gatehouse
J A. 1996. Transgenic potato plants with enhanced resis-
tance to the peach-potato aphid Myzus persicae. Entomol
Exp Appl, 79: 295-307.
Hilder V A, Gatehouse A M R, Boulter D. 1993. Transgenic
Plants Conferring Insect Tolerance. New York: Academic
Press. 317-338.
Hilder V A, Powell K S, Gatehouse A M R, Gatehouse J A,
Gatehouse L N, Shi Y, Hamilton W D O, Merryweather A,
Newell C A, Timans J C, Peumans W J, van Damme E,
Boulter D. 1995. Expression of snowdrop lectin in transgenic
tobacco plants results in added protection against aphids.
Transgenic Res, 4: 18-25.
Hoffman M P, Zalom F G, Wilso V T, Silanick J M, Malyj L D,
Kiser J, Hilder V A, Barnes W M. 1992. Field evaluation of
transgenic tobacco containing genes encoding Bacillus
thuringiensis d-endotoxin or cowpea trypsin inhibitor: effi-
cacy against Helicoverpa zea (Lepidoptera: Noctuidae).
Econom Entomol, 85: 2516-2522.
Holsters M, de Waele D, Depicker A, Messens E, van Montagu
M, Schell J. 1978. Transfection and transformation of
Agrobacterium tumefaciens. Mol Gen Genet, 163: 181-
187.
Horsch R B, Fry J, Hoffmann N, Neidermeyer J, Rogers S G,
Fraley R T. 1988. Leaf Disc Transformation. Dordtrecht:
Kluwer Academic Publishers. 1-9.
Murashige T, Skoog F A. 1962. Revised medium for rapid growth
and bioassays with tobacco tissue cultures. Plant Physiol,
15: 473-479.
van Damme E J M, Goldstein I J, Peumans W J. 1991a. A com-
parative-study of mannose-binding lectins from the
Amaryllidaceae and Alliacea. Phytochemistry, 30: 509-514.
van Damme E J M, Hanae K, Fulvio P, Irwin J, Goldstein Ben P,
Fumio Y, Benny D, Peumans W J. 1991b. Biosynthesis,
primary structure and molecular cloning of snowdrop
(Galanthus nivalis L.) lectin. Eur J Biochem, 202: 23-30.
van Damme E J M, Goldstein I J, Vercammen G, Peumans W J.
1992. Lectins of members of the Amaryllidaceae are en-
coded by multigene families which show extensive
homologies. Plant Physiol, 86: 245-252.
van Damme E J M, Peumans W J, Barre A, Rougé P. 1998. Plant
lectin: a composite several distinct families of structurally
and evolutionary related proteins with diverse biological
roles. Crit Rev Plant Sci, 17: 575-692.
Powell K S, Gatehouse A M R, Hilder V A, Gatehouse J A. 1993.
Antimetabolic effects of plant lectins and plant and fungal
enzymes on the nymphal stages of two important rice pest,
Nilaparvata lugens and Nephotettix cinciteps. Entomol Exp
Appl, 66: 119-126.
Powell K S, Gatehouse A M R, Hilder V A, Gatehouse J A. 1995.
Antifeedant effects of plant lectins and enzymes on the
adult stage of the rice brown planthopper, Nilaparvata
lugens. Entomol Exp Appl, 75: 51-59.
Rahbe Y, Sauvion N, Febvay G, Peumans W J, Gatehouse A M R.
1995. Toxicity of lectins and processing of ingested pro-
teins in the pea aphid Acyrthosiphon pisum. Entomol Exp
Appl, 76: 143-155.
Rao K V, Rathore K S, Hodges T K, Fu X, Stoger E, Sudhakar D,
Williams S, Christou P, Bharathi M, Bown D P, Powell K
S, Spence J, Gatehouse A M, Gatehouse J A. 1998. Expres-
sion of snowdrop lectin (GNA) in transgenic rice plants
Acta Botanica Sinica 植物学报 Vol.46 No.7 2004772
(Managing editor: ZHAO Li-Hui)
confers resistance to rice brown planthopper. Plant J, 15:
469-485.
Shukle R H, Murdock L L. 1983. Lipoxygenease, trypsin inhibition,
and lectin from soybeans: affecting larval growth of
Manduca Sexta (Lepidoptera:Sphingidae). Environ
Entomol, 12: 787-791.
Tang K, Sun X, Hu Q, Wu A, Lin C H, Lin H J, Twyman R M,
Christou P, Feng T. 2001. Transgenic rice plants express-
ing the ferredoxin-like protein (AP1) from sweet pepper
show enhanced resistance to Xanthomonas oryzae pv.
Oryzae. Plant Sci, 160: 1035-1042.
Yao J-H, Sun X-F, Tang K-X. 2001. Molecular cloning of lectin
gene from Lycoris radiata. J Fudan Univ , 41: 102-105.
Wang X, Bauw G, van Damme E J, Peumans W J, Chen Z L, van
Montagu M, Angenon G, Dillen W. 2001. Gastrodianin-
like mannose-binding proteins: a novel class of plant pro-
teins with antifungal properties. Plant J, 25: 651-661.