Localization of cell wall polysaccharides in nonarticulated laticifers ofAsclepias speciosa Torr.

Summary Asclepias speciosa Torr, has latex-containing cells known as nonarticulated laticifers. In stem sections of this species, we have analyzed the cell walls of nonarticulated laticifers and surrounding cells with various stains, lectins, and monoclonal antibodies. These analyses revealed that laticifer walls are rich in (1→4) β-D-glucans and pectin polymers. Immunolocalization of pectic epitopes with the antihomogalacturonan antibodies JIM5 and JIM7 produced distinct labeling patterns. JIM7 labeled all cells including laticifers, while JIM5 only labeled mature epidermal cells and xylem elements. Two antibodies, LM5 and LM6, which recognize rhamnogalacturonan I epitopes distinctly labeled laticifer walls. LM6, which binds to a (l→5) α-arabinan epitope, labeled laticifer walls more intensely than walls of other cells. LM5, which recognizes a (1→4) β-D-galac-tan epitope, did not label laticifer segments at the shoot apex but labeled more mature portions of laticifers. Also the LM5 antibody did not label cells at the shoot apical meristem, but as cells grew and matured the LM5 epitope was expressed in all cells. LM2, a monoclonal antibody that binds to β-D-glucuronic acid residues in arabinogalactan proteins, did not label laticifers but specifically labeled sieve tubes. Sieve tubes were also specifically labeled byRicinus communis agglutinin, a lectin that binds to terminal β-D-galactosyl residues. Taken together, the analyses conducted showed that laticifer walls have distinctive cytochemical properties and that these properties change along the length of laticifers. In addition, this study revealed differences in the expression of pectin and arabinogalactan protein epitopes during shoot development or among different cell types.     

Immunodetection of pectin and arabinogalactan protein epitopes during pollen exine formation of Beta vulgaris L.

Summary. We present the results of ultrastructural and immunocytochemical studies of sugar beet microsporocytes during the developmental phase that begins with the first meiotic metaphase and ends with the formation of young tetrads. The most prominent feature noted during this period of microsporogenesis was the presence of numerous cisternae of endoplasmic reticulum which frequently lie perpendicular to the surface of the plasma membrane and eventually fuse to it. Microscopic observations have been combined with the detection of several carbohydrate epitopes representing pectins and arabinogalactan proteins in the primexine and incipient exine. Pectin domains that possess both low and highly methylesterified epitopes, as well as pectin side chains enriched in (1→4)-β-D-galactose residues, are deposited in this young microspore wall. The epitopes of arabinogalactan protein that bind to JIM13, JIM8, and LM2 antibodies are localised within the callose wall surrounding posttelophase tetrads. The possibility of endoplasmic-reticulum involvement in the synthesis, transport, or metabolism of several microspore wall compounds is discussed. Correspondence and reprints: Institute of Plant Breeding and Acclimatization, Powstańców Wielkopolskich 10, 85-090 Bydgoszcz, Poland.     

Arabinoxylan and (1→3),(1→4)-β-glucan deposition in cell walls during wheat endosperm development

Arabinoxylans (AX) and (1→3),(1→4)-β-glucans are major components of wheat endosperm cell walls. Their chemical heterogeneity has been described but little is known about the sequence of their deposition in cell walls during endosperm development. The time course and pattern of deposition of the (1→3) and (1→3),(1→4)-β-glucans and AX in the endosperm cell walls of wheat (Triticum aestivum L. cv. Recital) during grain development was studied using specific antibodies. At approximately 45°D (degree-days) after anthesis the developing walls contained (1→3)-β-glucans but not (1→3),(1→4)-β-glucans. In contrast, (1→3),(1→4)-β-glucans occurred widely in the walls of maternal tissues. At the end of the cellularization stage (72°D), (1→3)-β-glucan epitopes disappeared and (1→3),(1→4)-β-glucans were found equally distributed in all thin walls of wheat endosperm. The AX were detected at the beginning of differentiation (245°D) in wheat endosperm, but were missing in previous stages. However, epitopes related to AX were present in nucellar epidermis and cross cells surrounding endosperm at all stages but not detected in the maternal outer tissues. As soon as the differentiation was apparent, the cell walls exhibited a strong heterogeneity in the distribution of polysaccharides within the endosperm.     

The differences in cell wall composition in leaves and regenerating protoplasts of Beta vulgaris and Nicotiana tabacum

Cell wall composition in leaves and regenerating leaf-derived protoplasts was studied in Beta vulgaris L. and Nicotiana tabacum L. Several oligosaccharides that characterize arabinogalactan proteins (AGPs) and pectins were visualized in situ by a series of immunocytochemical reactions. The most conspicuous difference between the two species involved the expression of AGP epitopes that bind LM2 and MAC207 in only sugar beet cells; both epitopes being characterized by the presence of glucuronic acid (GlcA). Moreover, B. vulgaris leaves and protoplast-derived cells showed lower content of pectin side-chains bearing (1→4)-β-D-galactose residues as compared to N. tabacum.     

Temporal and spatial appearance of wall polysaccharides during cellularization of barley (Hordeum vulgare) endosperm

Barley endosperm begins development as a syncytium where numerous nuclei line the perimeter of a large vacuolated central cell. Between 3 and 6 days after pollination (DAP) the multinucleate syncytium is cellularized by the centripetal synthesis of cell walls at the interfaces of nuclear cytoplasmic domains between individual nuclei. Here we report the temporal and spatial appearance of key polysaccharides in the cell walls of early developing endosperm of barley, prior to aleurone differentiation. Flowering spikes of barley plants grown under controlled glasshouse conditions were hand-pollinated and the developing grains collected from 3 to 8 DAP. Barley endosperm development was followed at the light and electron microscope levels with monoclonal antibodies specific for (1→3)-β-d-glucan (callose), (1→3,1→4)-β-d-glucan, hetero-(1→4)-β-d-mannans, arabino-(1→4)-β-d-xylans, arabinogalactan-proteins (AGPs) and with the enzyme, cellobiohydrolase II, to detect (1→4)-β-d-glucan (cellulose). Callose and cellulose were present in the first formed cell walls between 3 and 4 DAP. However, the presence of callose in the endosperm walls was transient and at 6 DAP was only detected in collars surrounding plasmodesmata. (1→3,1→4)-β-d-Glucan was not deposited in the developing cell walls until approximately 5 DAP and hetero-(1→4)-β-d-mannans followed at 6 DAP. Deposition of AGPs and arabinoxylan in the wall began at 7 and 8 DAP, respectively. For arabinoxylans, there is a possibility that they are deposited earlier in a highly substituted form that is inaccessible to the antibody. Arabinoxylan and heteromannan were also detected in Golgi and associated vesicles in the cytoplasm. In contrast, (1→3,1→4)-β-d-glucan was not detected in the cytoplasm in endosperm cells; similar results were obtained for coleoptile and suspension cultured cells.     

Modification of cambial cell wall architecture during cambium periodicity in Populus tomentosa Carr.

Cambium periodicity is correlated with changes in the cambial cell wall, but the heterogeneity of cell wall structure and composition makes it difficult to give an accurate interpretation, especially for complex secondary vascular tissues. A combination of different methods is necessary to reveal the structure of this complex cell wall. In this study, the cell wall architecture and composition of active and dormant cambial cells in Populus tomentosa were investigated by a combination of light microscopy, rapid-freezing and deep-etching electron microscopy, Fourier-transform infrared microspectroscopy and immuno-histochemistry. The results showed that the architecture of dormant cambial cell walls displayed a multi-layered structure, denser fibril network, smaller pore size, and fewer crosslinks between microfibrils than active cambial cell walls. The FTIR spectra of cell walls from active and dormant cambium showed differences in the intensity of bands near 1,740, 1,629, 1,537, 1,240, and 830 cm⁻¹, which reflected differences in cell wall composition. Immuno-labeling indicated that high methyl-esterified homogalacturonan and (1 → 4)-β-d-galactan epitopes were abundant and distributed in active cambial cell walls, and relatively de-esterified homogalacturonan and (1 → 5)-α-l-arabinan epitopes had weak labeling in the active cambium, while almost no labeling or very weak labeling for high methyl-esterified homogalacturonan, (1 → 4)-β-d-galactan and (1 → 5)-α-l-arabinan epitopes occurred in dormant cambial cells, except for the de-esterified homogalacturonan epitope, which was abundant in dormant cambial cells. These results demonstrate that there are great differences, both in structure and composition, between active and dormant cambial cell walls, which reflect their dynamic changes during cambium activity.     

Structures and cytotoxic activities of two new asterosaponins from the antarctic starfish <Emphasis Type="Italic">Diplasterias brucei</Emphasis>

Two new asterosaponins, diplasteriosides A and B, bearing the same β-D-Fucp-(1→2)-β-D-Galp-(1→4)-[β-D-Quip-(1→2)]-β-D-Quip-(1→3)-β-D-Quip-(1→ oligosaccharide chains linked to the C6 atom of the known genins, 3-O-sulfates of thornasterols A and B, respectively, were isolated from the Antarctic Diplasterias brucei starfish along with the previously known asteriidoside A. The structures of the new compounds were elucidated by two-dimensional NMR spectroscopy and mass spectrometry. Cytotoxicities of the isolated asterosaponins against the human colon cancer HCT-116, human breast cancer T-47D cell line, and human melanoma cancer RPMI-7951 cell lines were studied.     

Differences among the cell wall galactomannans from Aspergillus wentii and Chaetosartorya chrysella and that of Aspergillus fumigatus

The alkali extractable and water-soluble cell wall polysaccharides F1SS from Aspergillus wentii and Chaetosartorya chrysella have been studied by methylation analysis, 1D- and 2D-NMR, and MALDI-TOF analysis. Their structures are almost identical, corresponding to the following repeating unit: [→ 3)-β-D-Galf-(1 → 5)-β-D-Galf-(1 →] _n → mannan core. The structure of this galactofuranose side chain differs from that found in the pathogenic fungus Aspergillus fumigatus, in other Aspergillii and members of Trichocomaceae: [→ 5)-β-D-Galf-(1 →] _n → mannan core. The mannan cores have also been investigated, and are constituted by a (1 → 6)-α-mannan backbone, substituted at positions 2 by chains from 1 to 7 residues of (1 → 2) linked α-mannopyranoses. Published in 2004. This revised version was published online in July 2006 with corrections to the Cover Date.     

Characterization of the <Emphasis Type="Italic">Pragia fontium</Emphasis> Lipopolysaccharides

Lipopolysaccharides (LPSs) of two strains Pragia fontium 97U116 and 27480 were isolated and characterized; they were close to those of other representatives of the family Enterobacteriaceae in fatty acid composition and contained, respectively, 3-hydroxytetradecanoic acid as the predominant component (45.8 and 45.1%), tetradecanoic (23.5 and 28.9%), hexadecanoic (12.6 and 7.9%), hexadecenoic (12.6 and 7.9%), and dodecanoic (4.9 and 4.2%) fatty acids. The O-specific polysaccharides consisted of linear penta- and tetrasaccharide repeating units: →2)-α-D-Galf-(1→3)-α-L-Rhap2Ac-(1→4)-α-D-GlcpNAc-(1→2)-α-L-Rhap-(1→3)-β-D-GlcpNAc-(1→ →4)-β-D-ManpNAc3NAcA-(1→2)-α-L-Rhap-(1→3)-β-L-Rhap-(1→4)-α-D-GlcpNAc-(1→ The LPSs of P. fontium 97U116 and 27480 were serologically active and belonged to different serogroups; they were less toxic than those of strain E. coli O55:B5, but more pyrogenic than the Pyrogenal preparation.     

Cell wall (1 → 3)- and (1 → 3, 1 → 4)-β-glucans during early grain development in rice (Oryza sativa L.)

Immunogold labeling was used to study the distribution of (1 → 3)-β-glucans and (1 → 3, 1 → 4)-β-glucans in the rice grain during cellularization of the endosperm. At approximately 3–5 d after pollination the syncytial endosperm is converted into a cellular tissue by three developmentally distinct types of wall. The initial free-growing anticlinal walls, which compartmentalize the syncytium into open-ended alveoli, are formed in the absence of mitosis and phragmoplasts. This stage is followed by unidirectional (centripetal) growth of the anticlinal walls mediated by adventitious phragmoplasts that form between adjacent interphase nuclei. Finally, the periclinal walls that divide the alveoli are formed in association with centripetally expanding interzonal phragmoplasts following karyokinesis. The second and third types of wall are formed alternately until the endosperm is cellular throughout. All three types of wall that cellularize the endosperm contain (1 → 3)-β-glucans but not (1 → 3, 1 → 4)-β-glucans, whereas cell walls in the surrounding maternal tissues contain considerable amounts of (1 → 3, 1 → 4)-β-glucans with (1 → 3)-β-glucans present only around plasmodesmata. The callosic endosperm walls remain thin and cell plate-like throughout the cellularization process, appearing to exhibit a prolonged juvenile state. Received: 7 January 1997 / Accepted: 11 February 1997     

Catalytic properties and amino acid sequence of endo-1→3-β-D-glucanase from the marine mollusk <Emphasis Type="Italic">Tapes literata</Emphasis>

A specific 1→3-β-D-glucanase with molecular mass 37 kDa was isolated in homogeneous state from crystalline style of the commercial marine mollusk Tapes literata. It exhibits maximal activity within the pH range from 4.5 to 7.5 at 45dgC. The 1→3-β-D-glucanase catalyzes hydrolysis of β-1→3 bonds in glucans as an endoenzyme with retention of bond configuration, and it has transglycosylating activity. The K _m for hydrolysis of laminaran is 0.25 mg/ml. The enzyme is classified as a glucan endo-(1→3)-β-D-glucosidase (EC 3.2.1.39). The cDNA encoding this 1→3-β-D-glucanase from T. literata was sequenced, and the amino acid sequence of the enzyme was determined. The endo-1→3-β-D-glucanase from T. literata was assigned to the 16th structural family (GHF 16) of O-glycoside hydrolases.     

Carbohydrate antigens and lectin receptors of the plasma membrane of carrot cells

Summary A monoclonal antibody (JIM 1) has been derived, subsequent to immunization of rats with carrot protoplasts and a hybridoma screen of protoplast immunoagglutination, that recognizes a determinant at the outer face of the plasma membrane of carrot cells. The binding of JIM 1 is readily inhibitable by -D-galactosyl residues. Although weakly cross-reacting with an extracellular arabinogalactan protein, isolated from the conditioned medium of suspension-cultured carrot cells, JIM 1 does not recognize arabinogalactan proteins associated with the plasma membrane. The plasma membrane antigen recognized by JIM 1 was of low molecular weight and was sensitive to both periodate treatment and a protease. JIM 1 therefore defines a new class of galactosyl-residue containing plant cell surface antigen, distinct from the arabinogalactan proteins. However, the extracellular arabinogalactan protein and related plasma membrane-associated glycoproteins are demonstrated to bind the anti-galactose plant lectin peanut agglutinin.Abbrevations AGP arabinogalactan protein - McAb monoclonal antibody - PNA peanut agglutinin     

Low-Molecular-Weight Compounds

Self-association of caffeine has been investigated using mass spectrometry. It was found that associates are composed of caffeine trimers and hexamers. The possibility of complex formation of caffeine with triterpene glycosides 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside of hederagenin and its 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosil-(1→6)-O-β-D-glucopyranosil ester have been considered. Under the experimental conditions, inclusion compounds do not form and only self-associates of caffeine and glycosides are found.     

Structural analysis of the exopolysaccharide produced by <Emphasis Type="Italic">Streptococcus thermophilus</Emphasis> ST1 solely by NMR spectroscopy

The use of lactic acid bacteria in fermentation of milk results in favorable physical and rheological properties due to in situ exopolysaccharide (EPS) production. The EPS from S. thermophilus ST1 produces highly viscous aqueous solutions and its structure has been investigated by NMR spectroscopy. Notably, all aspects of the elucidation of its primary structure including component analysis and absolute configuration of the constituent monosaccharides were carried out by NMR spectroscopy. An array of techniques was utilized including, inter alia, PANSY and NOESY-HSQC TILT experiments. The EPS is composed of hexasaccharide repeating units with the following structure: → 3)[α-d-Glcp-(1 → 4)]-β-d-Galp-(1 → 4)-β-d-Glcp-(1 → 4)[β-d-Galf-(1 → 6)]-β-d-Glcp-(1 → 6)-β-d-Glcp-(1 →, in which the residues in square brackets are terminal groups substituting backbone sugar residues that consequently are branch-points in the repeating unit of the polymer. Thus, the EPS consists of a backbone of four sugar residues with two terminal sugar residues making up two side-chains of the repeating unit. The molecular mass of the polymer was determined using translational diffusion experiments which resulted in M_w = 62 kDa, corresponding to 64 repeating units in the EPS.     

Electrophoretic profiling and immunocytochemical detection of pectins and arabinogalactan proteins in olive pollen during germination and pollen tube growth

Background and Aims

Cell wall pectins and arabinogalactan proteins (AGPs) are important for pollen tube growth. The aim of this work was to study the temporal and spatial dynamics of these compounds in olive pollen during germination.

Methods

Immunoblot profiling analyses combined with confocal and transmission electron microscopy immunocytochemical detection techniques were carried out using four anti-pectin (JIM7, JIM5, LM5 and LM6) and two anti-AGP (JIM13 and JIM14) monoclonal antibodies.

Key Results

Pectin and AGP levels increased during olive pollen in vitro germination. (1 → 4)-β-d-Galactans localized in the cytoplasm of the vegetative cell, the pollen wall and the apertural intine. After the pollen tube emerged, galactans localized in the pollen tube wall, particularly at the tip, and formed a collar-like structure around the germinative aperture. (1 → 5)-α-l-Arabinans were mainly present in the pollen tube cell wall, forming characteristic ring-shaped deposits at regular intervals in the sub-apical zone. As expected, the pollen tube wall was rich in highly esterified pectic compounds at the apex, while the cell wall mainly contained de-esterified pectins in the shank. The wall of the generative cell was specifically labelled with arabinans, highly methyl-esterified homogalacturonans and JIM13 epitopes. In addition, the extracellular material that coated the outer exine layer was rich in arabinans, de-esterified pectins and JIM13 epitopes.

Conclusions

Pectins and AGPs are newly synthesized in the pollen tube during pollen germination. The synthesis and secretion of these compounds are temporally and spatially regulated. Galactans might provide mechanical stability to the pollen tube, reinforcing those regions that are particularly sensitive to tension stress (the pollen tube–pollen grain joint site) and mechanical damage (the tip). Arabinans and AGPs might be important in recognition and adhesion phenomena of the pollen tube and the stylar transmitting cells, as well as the egg and sperm cells.     

Identification of biosynthetic intermediates of the extracellular polysaccharide viilian in Lactococcus lactis subspecies cremoris SBT 0495

Lactococcus lactis subspecies cremoris SBT 0495 produces the phosphopolysaccharide viilian, which consists of the repeating unit β-d-glucosyl-(1→4)-(α-l-rhamnosyl-(1→2))-(α-d-galactose-1-phosphoryl-(→3)-β-galactosyl-(1→4)-β-d-glucose. A lipid extract was prepared from cells in the late exponential phase of growth and was hydrolyzed by hydrochloric acid under mild conditions to split lipid-linked intermediates in the extract into lipid and sugar moieties. Both moieties were purified by chromatographic techniques and were characterized to identify intermediates of the viilian biosynthetic pathway. A polyisoprenoid isolated from the chloroform-soluble fraction of the hydrolyzed lipid extract was identified by mass spectrometry as undecaprenol. Saccharides isolated from the water-soluble fraction of the hydrolyzed lipid extract by anion-exchange chromatography, were characterized by glycosidic linkage analysis to discriminate sugar moieties of intermediates of viilian biosynthesis from compounds liberated from cell wall components. Some oligosaccharide analogues contain a glycerol residue, suggesting that these are fragments of glycosylglycerides and/or lipoteichoic acid. Three fragments were identified to be glucose, galactosyl-(1→4)-glucose, and rhamnosyl-(1→2)-galactosyl-(1→4)-glucose, which are in agreement with the structure of the repeating unit of viilian. These saccharides most likely represent the first three steps of the sequential assembly of the repeating unit of the undecaprenol assembly. Received: 2 November 1998 / Accepted: 3 March 1999     

Regulation of polysaccharide breakdown during auxin-induced cell wall loosening

Auxin induces cell elongation by increasing the extensibility of the cell wall. Biochemical modifications of wall constituents lead to such changes in the mechanical properties of the cell wall (wall loosening). The results obtained in the studies using antibodies and lectins as specific probes indicate that the breakdown of xyloglucans in dicotyledons and (1→3), (1→4)-β-glucans in Poaceae is involved in auxin-induced wall loosening. In dicotyledons, xyloglucans are degraded by the direct hydrolysis with an endoglucanase to oligosaccharides and by the two-step reaction via a product with intermediate size. (1→3), (1→4)-β-Glucan breakdown in Poaceae coleoptiles is mediated by the two-step reaction with endo-and exoglucanases. Although auxin inducesde novo synthesis of some hydrolases involved in breakdown of these polysaccharides, the breakdown activity is also regulated by the wall environment such as pH, by the mobility of hydrolases through wall networks, by the interaction of hydrolases with wall polysaccharide complex, and by the presence and the concentrations of different types of regulatory molecules. Recipient of the Botanical Society Award of Young Scientists, 1992.     

Mass spectrometry of triterpene glycosides molecular complexation with purine bases of nucleic acids

For the first time, the molecular complexation of adenine and guanine with hederagenin 3-O-α-L-rhamnopyranosyl-(1 2)-O-α-L-arabinopyranoside (α-hederin) and its 28-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester (hederasaponin C) was investigated using the method of electrospray ionization mass spectrometry. Guanine forms more diversely composed complexes than adenine.     

Structure of the O-Specific polysaccharide from Shewanella japonica KMM 3601 containing 5,7-Diacetamido-3,5,7,9-tetradeoxy-D-glycero-D-talo-non-2-ulosonic acid

Structure of the O-specific polysaccharide chain of the lipopolysaccharide (LPS) of Shewanella japonica KMM 3601 was elucidated. The initial and O-deacylated LPS as well as a trisaccharide representing the O-deacetylated repeating unit of the O-specific polysaccharide were studied by sugar analysis along with ¹H and ¹³C NMR spectroscopy. The polysaccharide was found to contain a rare higher sugar, 5,7-diacetamido-3,5,7,9-tetradeoxy-d-glycero-d-talo-non-2-ulosonic acid (a derivative of 4-epilegionaminic acid, 4eLeg). The following structure of the trisaccharide repeating unit was established: →4)-α-4eLegp5Ac7Ac-(2→4)-β-d-GlcpA3Ac-(1→3)-β-d-GalpNAc-(1→.     

A review of acacic acid-type saponins from Leguminosae-Mimosoideae as potent cytotoxic and apoptosis inducing agents

The aim of this review is to highlight updated results on the biologically active saponins from Leguminosae-Mimosoideae. Acacic acid-type saponins (AATS), is a class of very complex glycosides possessing a common aglycon unit of the oleanane-type (acacic acid = 3β, 16α, 21β trihydroxy-olean-12-en-28 oic acid), having various oligosaccharide moieties at C-3 and C-28 and an acyl group at C-21. About sixty molecules of this type have been actively explored in recent years from Leguminosae family, from a chemical point of view and some fifty were reported to possess cancer related activities. These include cytotoxic/antitumor, immunomodulatory, antimutagenic, and apoptosis inducing properties and appear to depend on the acylation and esterification by different moieties at C-21 and C-28 of the acacic acid-type aglycone. One can observe that the (6S) configuration of the outer monoterpenyl moiety (MT) seems more potent in mediating high cytotoxicity than its (6R) isomer. Furthermore, the trisaccharide moiety {β-d-Xylopyranosyl-(1→2)-β-d-Fucopyranosyl-(1→6)- N-Acetamido 2-β-d-Glucopyranosyl-} at C-3, the tetrasaccharide moiety {β-d-Glucopyranosyl-(1→3)-[α-L-Arabinofuranosyl-(1→4)]-α-l-Rhamnopyranosyl-(1→2)-β-d-Glucopyranosyl} at C-28 of the aglycone, and the inner MT hydroxylated at its C-9, having a (6S) configuration can be important substituent patterns for the induction of apoptosis of AATS. Because of their interesting cytotoxic/apoptosis inducing activity, some AATS can be useful in the search for new potential antitumor agents from Fabaceae. Furthermore, the sequence 28-O-{Glc-(1→3)-[Ara_f-(1→4)]-Rha-(1→2)-Glc-Acacic acid}, often encountered in the genera Acacia, Albizia, Archidendron, and Pithecellobium may represent a chemotaxonomic marker of the Mimosoideae subfamily.