Characterization and molecular cloning of mannose‐binding lectins from the Orchidaceae species Listera ovata, Epipactis helleborine and Cymbidium hybrid

Abstract

Mannose-binding lectins were purified from the leaves of three Orchidaceae species, namely Listera ovata (twayblade), Epipactis helleborine (broad-leaved helleborine) and Cymbidium hybrid, using affinity chromatography on mannose-Sepharose-4B. Apparently, the Orchidaceae lectins are dimeric proteins composed of lectin subunits of 12-13 kDa. All of the isolated lectins exhibit exclusive specificity towards mannose.A cDNA library constructed from poly(A) rich RNA isolated from leaves of L. ovata was screened for cDNA clones encoding the lectin using colony hybridization. Since N-terminal sequence analysis of the twayblade lectin revealed some sequence similarity to the previously cloned mannose-binding lectin from Hippeastrum hybrid (amaryllis) ovaries, the amaryllis lectin cDNA clone was used as a probe to screen the L. ovata library. Subsequently, the cDNA clone encoding the L. ovata lectin was used to screen the cDNA libraries from the taxonomically related orchid species Cymbidium hybrid and E. helleborine. Sequence analysis of the lectin cDNA clones from different Orchidaceae species revealed approximately 50% sequence similarity both at the nucleotide and amino acid level.The Orchidaceae lectins are apparently translated from mRNAs consisting of approximately 800 nucleotides. The primary translation products are preproproteins which are converted into the mature lectins following post-translational modifications. Southern blot analysis of genomic DNA has shown that the lectins are most probably encoded by a family of closely related genes which is in good agreement with the sequence heterogeneity found between different lectin cDNA clones of one species.

The Major Tuber Storage Protein of Araceae Species Is a Lectin (Characterization and Molecular Cloning of the Lectin from Arum maculatum L.)

“…The Man-binding lectins (and lectin genes) from the plant families Amaryllidaceae, Alliaceae, and Orchidaceae have in particular been intensively studied, since they represent a superfamily of evolutionary well-conserved proteins with unique biological, physiological, and molecular biological properties (Van Damme et al, 1991b, 1992a, 1992b, 1993a, 1993b, 1994a, 1994b. Moreover, the finding that several members of this lectin family exhibited insecticidal activity in feeding experiments with both artificial diets and transgenic plants (Powell et al, 1993;Gatehouse et al, 1995) not only suggested that they are involved in the plant's defense but also demonstrated their potential use in crop protection against phytophagous invertebrates.…”

“…Characterization and molecular cloning of the Man-binding lectins from several Amaryllidaceae, Alliaceae, and Orchidaceae species demonstrated that they a11 belong to one large superfamily of Man-binding proteins that show a considerable overall sequence homology within the mature protein and, in addition, contain highly conserved domains (Van Damme et al, 1991b, 1992a, 199213, 1993a, 1993b, 1994a, 1994b. In search of possible new members of the Man-binding monocot lectins our attention was drawn to a previously isolated but yet uncharacterized agglutinin Plant Physiol.…”

Expression of cDNA for a bark lectin of Robinia in transgenic tobacco plants

“…The best-characterized lectins are those isolated from the seeds of leguminous plants [1]. Lectins have also been purified from leaves [2~], roots [5,6] and bulbs [7][8][9], and cDNAs that encode such lectins have been cloned [4,10,11]. The bark of woody plants is also a source of lectins [12][13][14][15].…”

Molecular Cloning of Two Different Mannose‐Binding Lectins from Tulip Bulbs

“…Sequence alignment of LECrxL-MI1 and previously cloned monocot mannose-binding lectins from Amaryllidaceae, Alliaceae and Orchidaceae revealed 39- (Van Damme et al, 1991), the Orchidaceae species Listeru ovuta (LECLOA1 and LECLOA2) (Van Damme et al, 1994), the Alliaceae species Allium sativum (ASAIdoml, ASAIdom2 and LECASAII) (Van Damme et al, 1992b), Alliurn ascalorzicurn (LECAAA) (Van Damme et al, 1993a), Alliurn cepa (LECACA) (Van Damme et al, 1993a), Alliurn porrum (LECAPA) (Van Damme et al, 1993a) and Alliurn ursinum (LECAUAGI and LECAUAG2) (Van Damme et al, 1993b), and the Araceae species Arum muculuturn (AMAldoml and AMAldom2) (Van Damme et al, 1995 b).…”

“…bark, bulbs, tubers, rhizomes and corms are particularly rich sources of lectins . Although representatives of most taxonomic groupings contain lectins in some vegetative tissue, the research on non-seed lectins has been focused on leaf, stem and root lectins of a few legume species (Etzler, 1994), bark lectins of a few trees (Nsimba-Lubaki and Peumans, 1986;Hankins et al, 1988;Yoshida et al, 1994;Van Damme et al, 199Sa) and on the bulb and tuberkorm lectins of a limited number of representatives of the monocot families Amaryllidaceae (Van Damme et al, 1987), Alliaceae (Van Damme et al, 1992b, 1993a, Orchidaceae (Van Damme et al, 1994), Araceae (Van Damme et al, 1995b) and, to a lesser extent, Liliaceae (Oda and Minami, 1986;Cammue et al, 1986;Oda et al, 1987;Koike et al, 1995). Surprisingly, all the lectins found thus far in storage organs of Amaryllidaceae, Alliaceae, Orchidaceae and Araceae species belong to a single superfamily Enzyme.…”