Cells with Crystals of Calcium Oxalate in the Leaves of Phaseolus vulgaris — a Comparison with those in Canavalia ensiformis

Leaflets of Phaseolus vulgaris contain crystals of calcium oxalate in the adaxial bundle sheath extensions. Most of the crystals accompany the lateral veins of third order. The average oxalate content of the leaves is 0.8% of dry weight. Some features of leaflet anatomy of Phaseolus and Canavalia are shown and the possible relation of anatomy to localization and development of crystals in each of the species is discussed. The majority of crystals in Phaseolus originate with the young leaflets newly unfolded. Calcium deficiency reduces number and size of crystals.     

Calcium and oxalate content of the leaves of Phaseolus vulgaris at different calcium supply in relation to calcium oxalate crystal formation

Soluble and insoluble oxalate and insoluble calcium were measured in the leaves of Phaseolus vulgaris. The plants were grown in nutrient solutions with two different concentrations of calcium. Two developmental stages of the leaves were studied. Although the content of insoluble calcium differs widely according to leaf age and growth conditions, the percentage bound in crystals is nearly the same in all cases. In the growing leaves, concentrations of total oxalate are independent of calcium supply, thus, showing that the known rise in numbers of crystals, and of cells containing them, is not induced via oxalate biosynthesis. Fully expanded leaves contain more oxalate when grown in a nutrient solution with higher calcium concentration. Amounts of oxalate in percent of dry weight are similar to those given in the literature for other legume leaves.     

Quantitative determination of calcium oxalate and oxalate in developing seeds of soybean (Leguminosae)

Developing soybean seeds accumulate very large amounts of both soluble oxalate and insoluble crystalline calcium (Ca) oxalate. Use of two methods of detection for the determination of total, soluble, and insoluble oxalate revealed that at +16 d postfertilization, the seeds were 24% dry mass of oxalate, and three-fourths of this oxalate (18%) was bound Ca oxalate. During later seed development, the dry mass of oxalate decreased. Crystals were isolated from the seeds, and X-ray diffraction and polarizing microscopy identified them as Ca oxalate monohydrate. These crystals were a mixture of kinked and straight prismatics. Even though certain plant tissues are known to contain significant amounts of oxalate and Ca oxalate during certain periods of growth, the accumulation of oxalate during soybean seed development was surprising and raises interesting questions regarding its function.     

Cellular ultrastructure and crystal development in Amorphophallus (Araceae)

Background and Aims: Species of Araceae accumulate calcium oxalate in the form ofcharacteristically grooved needle-shaped raphide crystals andmulti-crystal druses. This study focuses on the distributionand development of raphides and druses during leaf growth inten species of Amorphophallus (Araceae) in order to determinethe crystal macropatterns and the underlying ultrastructuralfeatures associated with formation of the unusual raphide groove. Methods: Transmission electron microscopy (TEM), scanning electron microscopy(SEM) and both bright-field and polarized-light microscopy wereused to study a range of developmental stages. Key Results: Raphide crystals are initiated very early in plant development.They are consistently present in most species and have a fairlyuniform distribution within mature tissues. Individual raphidesmay be formed by calcium oxalate deposition within individualcrystal chambers in the vacuole of an idioblast. Druse crystalsform later in the true leaves, and are absent from some species.Distribution of druses within leaves is more variable. Drusesinitially develop at leaf tips and then increase basipetallyas the leaf ages. Druse development may also be initiated incrystal chambers. Conclusions: The unusual grooved raphides in Amorphophallus species probablyresult from an unusual crystal chamber morphology. There aremultiple systems of transport and biomineralization of calciuminto the vacuole of the idioblast. Differences between raphideand druse idioblasts indicate different levels of cellular regulation.The relatively early development of raphides provides a defensivefunction in soft, growing tissues, and restricts build-up ofdangerously high levels of calcium in tissues that lack theability to adequately regulate calcium. The later developmentof druses could be primarily for calcium sequestration.     

Plant calcium oxalate crystal formation, function, and its impact on human health

Crystals of calcium oxalate have been observed among members from most taxonomic groups of photosynthetic organisms ranging from the smallest algae to the largest trees.The biological roles for calcium...     

草酸钙结晶在几种凤仙花属植物中的特征及其分类学意义

首次研究了7种凤仙花属(ImpatiensL.)植物茎的解剖学及细胞组织中草酸钙结晶的特征.结果表明,7种凤仙花属植物茎的解剖学结构非常近似,而茎中草酸钙结晶特征则差异显著,7种凤仙花属植物茎中均有草酸钙针晶,根据草酸钙结晶形态特征的不同,将针晶分为3种类型,即针晶束、针晶簇和散针晶.其中,黄金凤、长角凤仙花、锐齿凤仙花和红纹凤仙花有针晶束分布,而湖北凤仙花、紫花黄金凤和窄萼凤仙花则无针晶束分布,只有针晶簇或散针晶分布;此外,针晶的形态、长度、排列方式及丰富程度等在不同的物种中亦有差异.草酸钙结晶特征对凤仙花属植物的分类具有一定的科学意义.     

Calcium channels are involved in calcium oxalate crystal formation in specialized cells of Pistia stratiotes L

BACKGROUND AND AIMS: Pistia stratiotes produces large amounts of calcium (Ca) oxalate crystals in specialized cells called crystal idioblasts. The potential involvement of Ca(2+) channels in Ca oxalate crystal formation by crystal idioblasts was investigated. METHODS: Anatomical, ultrastructural and physiological analyses were used on plants, fresh or fixed tissues, or protoplasts. Ca(2+) uptake by protoplasts was measured with (45)Ca(2+), and the effect of Ca(2+) channel blockers studied in intact plants. Labelled Ca(2+) channel blockers and a channel protein antibody were used to determine if Ca(2+) channels were associated with crystal idioblasts. KEY RESULTS: (45)Ca(2+) uptake was more than two orders of magnitude greater for crystal idioblast protoplasts than mesophyll protoplasts, and idioblast number increased when medium Ca was increased. Plants grown on media containing 1-50 microM of the Ca(2+) channel blockers, isradipine, nifedipine or fluspirilene, showed almost complete inhibition of crystal formation. When fresh tissue sections were treated with the fluorescent dihydropyridine-type Ca(2+) channel blocker, DM-Bodipy-DHP, crystal idioblasts were intensely labelled compared with surrounding mesophyll, and the label appeared to be associated with the plasma membrane and the endoplasmic reticulum, which is shown to be abundant in idioblasts. An antibody to a mammalian Ca(2+) channel alpha1 subunit recognized a single band in a microsomal protein fraction but not soluble protein fraction on western blots, and it selectively and heavily labelled developing crystal idioblasts in tissue sections. CONCLUSIONS: The results demonstrate that Ca oxalate crystal idioblasts are enriched, relative to mesophyll cells, in dihydropyridine-type Ca(2+) channels and that the activity of these channels is important to transport and accumulation of Ca(2+) required for crystal formation.     

Development of the crystalliferous cuticle of Chamaecyparis lawsoniana (A. Murr.) Pari. (Gupressaceae)

A developmental study of the cuticle has shown that it consists of a homogeneous cuticle proper apposed on the wall and a heterogeneous cuticular layer generated by intussusception of cutin into the wall. At an early stage, the adcrusted cuticle proper is underlain by a ruthenium red-positive layer in which the cuticular layer originates. The origin of the anticlinal flange is referable to an electron-dense, ruthenium red-positive ridge which arises above the anticlinal wall and which also becomes cutinized. At leaf maturity, the inner surface of the cuticular layer, including that of the flange, forms interdigitating protuberances with the cell wall.
Development of the cuticle coincides with deposition of crystals of calcium oxalate in the epidermal cell wall. Initiation of large, early-formed crystals is associated with electron-opaque membranous structures formed close and parallel to the plasmalemma in the young cell wall. Crystals undergo periclinal and anticlinal growth and subsequently become engulfed within the cuticle by development of the cuticular layer. Cutin/polysaccharide interaction during development and the significance of crystal deposition are discussed.     

Calcium oxalate crystals of some <Emphasis Type=Italic>Crataegus</Emphasis> (Rosaceae) species growing in Aegean region

In this study, Ca oxalate crystals were isolated from the leaves and X-ray diffraction identified them as weddelite in Crataegus pontica C. Koch, C. stevenii Polar., C. monogyna ssp. monogyna Jacq. in C. orientalis var. orientalis Pallas ex Bieb. both whewellite and weddelite crystals were found. Although there were some differences among the soluble and insoluble oxalate contents, they were not notable in the species of C. stevenii (10%; 18%), C. orientalis (12.4%; 15%), C. monogyna (12.9%; 13%), whereas in C. pontica the difference was so great with the lowest soluble (4%), and highest (28%) insoluble oxalate content. Crystals have tetragonal or prismatic shape in general but tetrahedral kinked and straight shapes were seen in C. orientalis, tetragonal aggregates in C. stevenii, and also pseudo-tetrahedral cordate (heart) shape were found in C. monogyna ssp. monogyna and C. pontica. As the crystal biomineralization is under genetic control, this characteristic hydration state of crystals of Crataegus orientalis var. orientalis must be important for systematic phylogenetics.     

Developmentally regulated antigen associated with calcium crystals in tobacco anthers

We have found and characterized an antigen associated with crystal-containing cells in the stomium and connective tissue of the anthers of Nicotiana tabacum L. (tobacco). The antigen, defined by the monoclonal antibody NtF-8B1, localizes to subcellular regions surrounding the crystals. At the light-microscope level, the antigen is detectable just after the first appearance of crystals in the connective tissue of the anther, and at approximately the same time as the appearance of crystals in the stomium. The antigen is not detectable on a Western blot, and gave inconclusive results on a test of periodate sensitivity. It is not the crystals themselves, nor is the presence of the crystals required for antibody recognition. The antigen is sensitive to heat and protease treatment, indicating that it is a protein. The antigen is not tightly membrane-bound, in spite of its localization closely surrounding the crystals. Chemical tests indicate that the druse crystals in the stomium are calcium oxalate.Abbreviations ELISA enzyme-linked immunosorbent assay - FITC fluorescein isothiocyanate This research was supported by a National Science Foundation postdoctoral fellowship to B.L.H., by National Science Foundation grants DMB-87-15799 and to W.E.F. BSR-88-18035, and by U.S. Department of Agriculture grant GAM-89-01056. The authors thank Phillip T. Evans (Louisiana State University, Baton Rouge, USA), Wilma L. Lingle, Harry T. Horner, Jr. (Iowa State University), and A. Jack Fowler, Jr., for advice and helpful discussions.     

Structure of Crystal Cells and Influences of Leaf Development on Crystal Cell Development and Vice Versa in Phaseolus vulgaris (Leguminosae)

The structure of cells with calcium oxalate crystals and their nelghbouring cells has been studied by light and transmission electron microscopy at different stages of bean leaf development. Plants were grown with varying calcium supply to identify a possible influence of calcium nutrition on cell structure. Crystals are formed inside the vacuole of already highly vacuolated cells of bundle sheath extensions. The membrane around the crystal vacuole is continuous with the plasmalemma. The crystal vacuole contains membraneous structures. In the fully expanded leaf the crystal becomes ensheathed by wall material. Chloroplasts of bundle sheath extension cells, with or without crystals, are smaller, with fewer membranes, and with much narrower stroma regions than those of the palisade parenchyma. There is a stage in the young leaf when only the bundle sheath extension cells without crystals have starch grains in their chloroplasts. As their number is lower in plants grown with high calcium supply this means that, in this case, less cells are competent for photosynthesis.     

Relationship between selected morphological, anatomical and cytological characteristics of leaves and the level of tolerance to herbicides in strawberry cultivars

Foliar application of a mixture of herbicides containing phenmedipham, desmedipham and ethofumesate to the plants of nine strawberry cultivars revealed that there were differences in the level of plant tolerance to the applied chemicals. Light, polarized light and scanning electron microscopy were used to explain differences in tolerance to herbicides. The surface of strawberry leaves and cells was examined for stomata, hairs, trichomes, surface structures, cucticle, vacuole and oxalate crystals. The thicker the cuticle on the adaxial leaf surface, the thicker the layer of epicuticular waxes, greater number of large vacuoles and greater number of calcium oxalate crystals in epidermis cells were characteristic for cultivars with very good tolerance to herbicides. The cracking of epicuticular waxes layer was typical to cultivars with respectively low tolerance to herbicides.     

Heavy metal stress reduces the deposition of calcium oxalate crystals in leaves of Phaseolus vulgaris

Calcium oxalate (CaOx) crystals in plants may serve as a sink for the absorption of excess calcium, and they could play an important role in heavy metal detoxification. In this study, the effect of heavy metals and different calcium concentrations on the growth of calcium oxalate crystals in leaves of Phaseolus vulgaris was investigated. Different analytical techniques were used to determine the influence of exogenous lead and zinc on CaOx deposition and to detect a presence of these metals in CaOx crystals. We found a positive correlation between the calcium concentration in the nutrient medium and the production of calcium oxalate crystals in leaves of hydroponically grown plants. On the other hand, addition of the heavy metals to the nutrient medium decreased the number of crystals. Energy dispersive X-ray spectrometry did not detect the inclusion of heavy metals inside the CaOx crystals. Our investigation suggests that CaOx crystals do not play a major role in heavy metal detoxification in P. vulgaris but do play an important role in bulk calcium regulation.