bluuebunny/crossref_metadata_2025 huggingface dataset:
Histomorphology of rabbit thigh muscles: establishment of standard control values
Authors: RAB M. , NEUMAYER CH. , KOLLER R. , KAMOLZ L.‐P. , HASLIK W. , GASSNER R. , GIOVANOLI P. , SCHADEN G. , FREY M.
Published: March 2003

The thigh muscles of New Zealand White (NZW) rabbits are frequently used in experimental surgery, particularly for evaluation after reinnervation or ischaemia. Although histomorphometric analyses are regularly performed, morphological data for untreated thigh muscles in previously unoperated animals are not available. Specimens from the rectus femoris (RF), vastus medialis (VM) and adductor magnus (AM) muscles from both thighs were harvested in 7 untreated rabbits and were processed for histomorphometric evaluation. The right RF and VM were harvested in a further 5 rabbit hindlimbs after experimental denervation and reinnervation of the contralateral RF and subsequently processed for histomorphometric analysis. Muscle fibre type distribution, diameter and connective tissue content were evaluated on serial transverse cryosections reacted for ATPase and NADH tetrazolium reductase activity and statistical analysis was performed. In all untreated animals RF revealed the highest proportion of type I muscle fibres (right: 8.4±4%, left: 11.4±4.9%), whereas VM showed the highest percentage of IIa fibres (right: 31.9±5.5%, left: 28.3±7.8%) and AM the highest proportion of IIb/d fibres (right: 80.5±8.6%, left: 84.4±6.3%). Fibre type distribution and diameter in rabbits after contralateral experimental operations revealed a statistically significant difference from the data obtained in bilaterally untreated animals. Knowledge of the morphology of untreated muscles is fundamental to the understanding of changes induced by intervention to the ipsi and/or contralateral thigh muscles.
Bones in the heart skeleton of the otter (Lutra lutra)
Authors: EGERBACHER MONIKA , WEBER HEIKE , HAUER SILKE
Published: March 2003

In most mammalian species the cardiac skeleton is composed of coarse collagen fibres, fibrocartilage, and pieces of hyaline cartilage. Bone, the os cordis, is a regular constituent of the ruminant heart. The cardiac skeleton of the otter (Lutra lutra) has not previously been described. The skeleton in 30 otter hearts was studied by x‐ray analysis and light microscopy. Serial sections were cut parallel to the atrioventricular plane and histochemical staining methods were performed to identify connective tissue fibres, glycosaminoglycans, mineral deposits, and bone. Age and sex of the animals under investigation were considered. The otter heart skeleton was composed of coarse collagen fibres with intercalated pieces of fibrous and/or hyaline cartilage, calcified cartilage, and lamellar bone with red or white marrow. Pieces of hyaline cartilage were not clearly defined: a perichondrial layer was missing and coarse connective tissue continuously transformed into fibrous and hyaline cartilage. In both sexes the amount of cartilage and bone were found to increase with age.

Our results establish the presence of bony material in the heart skeleton of the otter, a small mammalian species. This finding indicates that differentiation of bone is not exclusively related to the size of the organ. Increasing amounts of calcified cartilage and bone correlated with increasing age.
Cerebellar connections to the dorsomedial and posterior nuclei of the hypothalamus in the rat
Authors: ÇAVDAR SAFİYE , ŞAN TANGÜL , AKER REZZAN , ŞEHİRLİ ÜMİT , ONAT FİLİZ
Published: March 2003

The stimulation or ablation of cerebellar structures has produced a variety of visceral responses, indicating a cerebellar role in visceral functions. Studies using anterograde and retrograde tracing methods have revealed connections between the hypothalamus and cerebellar structures. The aim of this study is to investigate the cerebellar connections of the dorsomedial (DMH) and posterior hypothalamic nuclei using retrograde axonal transport of horseradish peroxidase (HRP). In the present study, micro‐injection of HRP restricted within the borders of the DMH showed that the projections of this nucleus are not uniform throughout its extent. The posterior DMH receives projections from the cerebellum, whereas the anterior DMH does not. These projections were from the (greatest to least concentration) lateral (dentate), anterior interposed (emboliform), and medial (fastigial) cerebellar nuclei. In addition, both the anterior and posterior DMH receive projections from various areas of the brainstem which confirms earlier studies and provides detailed descriptions. This study also demonstrates the distribution of labelled neurons to cerebellar and brainstem nuclei following HRP injection into the posterior hypothalamic nucleus. It provides clear evidence for a direct cerebellar nuclei‐posterior DMH and cerebellar nuclei‐posterior hypothalamic nucleus connections. We suggest that the brainstem reticular nuclei and other connections, such as the solitary, trigeminal and vestibular nuclei, of both DMH and posterior hypothalamus may contribute to the indirect cerebellohypothalamic connections. These observations offer a new perspective on the question of how the cerebellum may influence autonomic activity.
Quantification of fibre type regionalisation: an analysis of lower hindlimb muscles in the rat
Authors: WANG L. C. , KERNELL D.
Published: March 2003

Newly developed concepts and methods for the quantification of fibre type regionalisation were used for comparison between all muscles traversing the ankle of the rat lower hindlimb (n = 12). For each muscle, cross‐sections from the proximodistal midlevel were stained for myofibrillar ATPase and classified as type I (‘slow’) or II (‘fast’). For the 11 ‘fast’ muscles (i.e. all except soleus), the muscle outline and the position of each type I fibre were digitised for further computer processing. Two potentially independent aspects of type I fibre regionalisation were evaluated quantitatively: (1) the degree to which type I fibres were restricted to a limited portion of the total cross‐sectional area (‘area‐regionalisation’) ; (2) the extent and direction of the difference (if any) between the centre of the muscle cross‐section and the calculated centre for the type I fibre cluster (‘vector regionalisation’). Statistical analysis showed that type I fibres were vector regionalised in practically all investigated muscles and area regionalised within most of them, the only consistent exceptions being peroneus brevis and peroneus digitorum 4, 5. In muscles with a high degree of area regionalisation the population of type I fibres also had a markedly eccentric intramuscular position (i.e. high vector regionalisation). A significant relationship was observed between the relative position of a muscle within the hindlimb (transverse plane) and the direction and degree of its type I fibre eccentricity. On average, the degree of type I fibre eccentricity was greater for muscles remote from the limb centre than for those situated more centrally. In addition, the intramuscular concentration of type I fibres was typically greatest towards the centre of the limb, the most striking exception being tibialis posterior. For the slow soleus muscle, which is centrally placed within the limb, our analysis concerned the type II fibres, which were found to be weakly vector regionalised but not significantly area regionalised. It is concluded that, within muscles of the rat's lower hindlimb, fibre type regionalisation is a general and graded phenomenon which may reflect differentiating (embryological?) mechanisms of a transmuscular significance. Furthermore, the analysis demonstrated the usefulness of our new methods and concepts for the quantification of fibre type regionalisation.
The three‐dimensional feto‐maternal vascular interrelationship during early bovine placental development: a scanning electron microscopical study
Authors: PFARRER CHRISTIANE , EBERT BRIGITTE , MIGLINO MARIA ANGELICA , KLISCH KARL , LEISER RUDOLF
Published: March 2003

Both the fetal and maternal microvasculature of bovine placentomes was examined by scanning electron microscopy of vascular casts. So far the development of the vascular architecture of the bovine placentome in early gestation has only been studied 2‐dimensionally due to technical difficulties arising from the fragility of the early placental blood vessels. Repeated experiments led to the selection of the microvascular corrosion casts presented here. The vasculature of the maternal compartment is supplied by large caruncular stalk or spiral arteries, which release short maternal stem arteries. In the 3rd month of gestation, these arteries branch into several arterioles at their base, thus providing the vascular framework for the lower part of the septal walls of the primary crypts. In the 4th month, due to progressive longitudinal growth of the stem arteries, branching into arterioles occurs not only at the base, but over the whole length of the stem arteries. These arterioles supply the capillary complexes of the septa which resemble the major part of the septal vasculature and face the secondary crypts. Further indentation results in the formation of tertiary crypt capillary complexes, encircling the earlier secondary unit. From the 6th month of gestation the architecture resembles the fully developed maternal placenta with stem arteries running directly to the fetal side to branch into 4 to 6 arterioles, which turn back to enter secondary and tertiary septa. Maternal venules, collecting the blood from the capillary bed of secondary and tertiary septa, converge onto stem veins leaving the caruncle via branches of the uterine vein. The fetal part of the placentome is supplied by the cotyledonary arteries, which branch into fetal stem arteries that are the tributary to single villous trees. Over their whole course towards the maternal side, these give off arterioles entering secondary villi. The tertiary or terminal villous vasculature consists of capillaries, which are organised in serial capillary loops. This system is progressively elaborated in the course of gestation. In the 4th month there are only finger‐like loops, whereas from the 6th month large fan‐like structures can be observed. In early gestation the maternal and fetal blood vessels meet predominantly in a countercurrent fashion, changing to the less efficient crosscurrent exchange when the tertiary unit develops. These results indicate the development of a highly elaborated fetomaternal villous‐crypt exchange system, already established in the 1st half of gestation, thus meeting the increasing needs of the fetus.
A novel branching pattern of the superior mesenteric artery found in the bullfrog (Rana catesbeiana) amphibian
Authors: ICHIMURA KOICHIRO , KOIZUMI KENJI , KUDOH HIROYUKI , MIYAKI TAKAYOSHI , SAKAI TATSUO
Published: March 2003

The branching and distribution patterns of the superior mesenteric artery were studied in 10 adult bullfrogs (Rana catesbeiana) after injection of coloured latex solution into the vasculature. The abdominal digestive organs in the bullfrog were mainly supplied by the coeliac artery and the superior mesenteric artery, both of which arose as a common trunk, the coeliacomesenteric artery, from the abdominal aorta. The coeliac artery supplied the stomach, liver, gallbladder and the pancreas, whereas the first branch of the superior mesenteric artery was the splenic artery with other branches supplying the greater part of intestine. The apex of the intestinal loop was defined as the region supplied by the trunk of the superior mesenteric artery, and its intestinal branches constituted a ‘nested formation' which had the following characteristics. (1) The branches of the trunk were distributed to both sides of the apex, and the distribution regions of younger branches were located more distant from the apex than those of older branches. (2) Two branches directed towards both sides of the trunk frequently made a common stem arising from the trunk. The second branch of the superior mesenteric artery constituted a secondary trunk and its distribution region could be defined as a secondary apex, since 1 of its branches also constituted a nested formation which was distributed to both sides of the primary and secondary apices. The intestinal branches of the superior mesenteric artery were divided into 4 types on the basis of their pattern of branching and course. It is suggested that the nested formation of the superior mesenteric artery in the bullfrog is a remnant of the vascular pattern of the tadpole, which possesses a double spiral mode of intestinal convolution, probably supplied by arteries with the nested formation in a latent form.
Morphological diversity in digital skin microstructure of didelphid marsupials
Authors: HAMRICK MARK W.
Published: March 2003

The purpose of this study was to investigate how didelphid marsupials have diversified in morphology of their claws and digital pads as they evolved different foraging preferences such as terrestrial, aquatic, and arboreal feeding behaviours. Both arboreal and more terrestrial didelphids have papillary ridges on the digital pads of the fore and hindfoot. In contrast, the papillary ridges on the pedal digital skin of the water opossum Chironectes minimus have been replaced by nonoverlapping, thickened epidermal scales. Chironectes also differs from the other didelphids studied in having finger tips with reduced claws and digital pads that are covered with raised epidermal scales having projecting, finger‐like cones arranged radially around the perimeter of each scale. The reduced claws and unusual digit skin microstructure of Chironectes likely improve this animal's ability to recognise and identify live animal prey under water using only its sense of touch.
The human vomeronasal organ. III. Postnatal development from infancy to the ninth decade
Authors: BHATNAGAR KUNWAR P. , SMITH TIMOTHY D.
Published: March 2003

The large literature on the human vomeronasal organ (VNO) offers little consensus as to its persistence in the adult. We have already documented the existence of the VNO from embryonic day 33 through the neonatal stages. This has now been extended to human adults: 27 cadaver nasal septa, aged 2–86 y, were either dissected or decalcified, serially sectioned, stained and examined. The consistent presence of the VNO is reported as a homologue, in the form of a duct‐like structure on the nasal septum at all ages. Also reported are size variability, pronounced bilateral asymmetry, a nonchemosensory pseudostratified ciliated epithelium with considerable structural variation and generally without medial–lateral differentiation, nasal septal glands opening into the VNO lumen, a lack of correlation between postnatal age and VNO size, visualisation of the human VNO with certainty by histological means alone, and a minute opening as its only visible surface feature. The human VNO is a discrete structure that should not be confused with the nasopalatine fossa, the septal mucosal pits or VNO openings.
Ultrastructural and histochemical study on the interrenal cells of the male stickleback (Gasterosteus aculeatus, Teleostea), in relation to the reproductive annual cycle
Authors: CIVININI ANNALENA , PADULA DANIELA , GALLO VALENTINA P.
Published: March 2003

The steroidogenic interrenal cells in the adrenal homologue of the male stickleback (Gasterosteus aculeatus) were studied in relation to the reproductive cycle by means of histological and ultrastructural observations, and using histochemical methods for the localisation of 3β‐hydroxysteroid dehydrogenase (3βHSD) and 17β‐hydroxysteroid dehydrogenase (17βHSD). To determine the various stages of the reproductive cycle, the testes were also examined by histological and histochemical methods (3βHSD). The results indicate that in this teleost the interrenal cells can undergo a cycle in which phases characterised by different cytological aspects are observed. During this cycle there is a renewal of organelles, in particular mitochondria and SER. Periodic degenerative processes are also found. Organelle cytology showed that the cell cycle has at least 3 different aspects during the year. An analogy with some cytological aspects of the adrenal zonation in mammals is possible. It is postulated that the interrenal gland activity could substitute or supplement androgen production by the testes.
The relationship of the number of Meissner's corpuscles to dermatoglyphic characters and finger size
Authors: DILLON YVONNE K. , HAYNES JULIE , HENNEBERG MACIEJ
Published: March 2003

This study investigated the relationships between the density of Meissner's corpuscles and the dermatoglyphic characteristics of human fingers. Dermatoglyphic prints and tissue samples were collected from the index (II) and ring (IV) fingers of 28 cadavers from the Medical School, University of Adelaide. Pattern types, pattern intensity, total ridge count and ridge breadth, were determined for each sample and the density of Meissner's corpuscles established by recording the mean number of Meissner's corpuscles underlying a 10 mm long line on the skin surface. No relationship was found between the density of Meissner's corpuscles and pattern type, pattern intensity or total ridge count. Negative correlations were found for the density of Meissner's corpuscles with both ridge width and size of fingers. Males were found to have significantly larger fingers, larger ridge breadth, and a lower density of Meissner's corpuscles per 10 mm compared with females. However, there was no difference between the total number of Meissner's corpuscles per finger in males and females. No significant differences were found in either the density of Meissner's corpuscles between antimeres or between the index and ring fingers. These results suggest that for both the left and right hand in males and females, there is a similar number of Meissner's corpuscles for both the index and ring fingers.
Comparative histochemical composition of muscle fibres in a pre‐ and a postvertebral muscle of the cervical spine
Authors: BOYD‐CLARK L. C. , BRIGGS C. A. , GALEA M. P.
Published: March 2003

References to histochemistry are extensive for human limb muscles but occur less frequently in relation to vertebral muscle. Most vertebral muscle literature has been concerned with muscle fibre characteristics in the lumbar and thoracic spine, due in large part to the incidence of low back pain and idiopathic scoliosis. However few studies have investigated the histochemical composition of neck muscles in humans: and, to our knowledge, no previous study has examined the antagonistic longus colli and multifidus muscle pair. In addition, while age‐related segmental degeneration is most prominent between C5 and C7, it is not known whether these osteoligamentous changes are paralleled by changes in muscle fibre ratio. Tissue blocks comprising muscle and bone from C5–C7 segments were harvested at autopsy from 16 subjects with ages ranging from 4 to 77 years. The prevertebral longus colli and postvertebral multifidus muscle pairs were randomly selected from one or other side in each subject. The tissue was frozen, sectioned and histochemically stained for myofibrillar adenosine triphosphatase. Analysis of muscle fibre types was performed by light microscopy. Wilcoxon paired t‐tests were used to ascertain whether intramuscular and intermuscular differences in fibre composition were significant. In addition, correlation and regression analyses were used to determine whether fibre type proportions changed in either muscle with increasing age. The present study has revealed histochemical differences between longus colli and multifidus at the level of the C5–C7 vertebral segments. Multifidus comprises a significantly greater proportion of type I than type II fibres. Longus colli comprises a significantly greater proportion of type II fibres than multifidus. Further there were no changes in fibre type proportion in either muscle with increasing age. These observations suggest that longus colli responds equally to postural and phasic demands, whereas multifidus is predominantly postural. Also it would appear that age‐related structural alterations in lower cervical segments are not paralleled by changes in muscle fibre ratio.
Evolution of the structure and function of the vertebrate tongue
Authors: Iwasaki Shin‐ichi
Published: March 2003

Studies of the comparative morphology of the tongues of living vertebrates have revealed how variations in the morphology and function of the organ might be related to evolutional events. The tongue, which plays a very important role in food intake by vertebrates, exhibits significant morphological variations that appear to represent adaptation to the current environmental conditions of each respective habitat. This review examines the fundamental importance of morphology in the evolution of the vertebrate tongue, focusing on the origin of the tongue and on the relationship between morphology and environmental conditions. Tongues of various extant vertebrates, including those of amphibians, reptiles, birds and mammals, were analysed in terms of gross anatomy and microanatomy by light microscopy and by scanning and transmission electron microscopy. Comparisons of tongue morphology revealed a relationship between changes in the appearance of the tongue and changes in habitat, from a freshwater environment to a terrestrial environment, as well as a relationship between the extent of keratinization of the lingual epithelium and the transition from a moist or wet environment to a dry environment. The lingual epithelium of amphibians is devoid of keratinization while that of reptilians is keratinized to different extents. Reptiles live in a variety of habitats, from seawater to regions of high temperature and very high or very low humidity. Keratinization of the lingual epithelium is considered to have been acquired concomitantly with the evolution of amniotes. The variations in the extent of keratinization of the lingual epithelium, which is observed between various amniotes, appear to be secondary, reflecting the environmental conditions of different species.
Keratinization and ultrastructure of the epidermis of late embryonic stages in the alligator (Alligator mississippiensis)
Authors: Alibardi Lorenzo , Thompson Michael B.
Published: March 2003

Using specific anti‐β keratin and general anti‐α keratin antibodies, keratins were located in the epidermis of the alligator during the final developmental stages by ultrastructural and immunocytochemical methods. The maturation of the bilayered periderm (= embryonic epidermis) coincides with the disappearance of cell organelles, including the 25–35‐nm‐thick coarse filaments, and the coalescing of α‐keratin filaments into a compact mass. The plasmalemma of peridermal cells forms a 15–25‐nm‐thick electron‐dense corneous envelope. These changes start at stage 25, about 3 weeks before hatching, and continue until hatching when the embryonic epidermis is shed. Immature β‐keratogenic cells beneath the embryonic epidermis accumulate immunolabelled β‐filaments which are packed into thin, electron‐pale β‐keratogenic cells in the corneous layer. Together, electron‐pale and electron‐dense materials form a compact 3–4‐nm filament pattern of β‐keratin. Melanosomes from epidermal melanocytes, incorporated into β‐cells, give rise to the banded skin pattern of hatchlings. β‐keratin production is much reduced in the hinge regions, where many α‐filaments remain packed together with lipid droplets or mucous granules into thinner, more electron‐dense, α‐cells. The keratinaceous material of the α‐cells is mostly concentrated along the cell membrane, while the lipid/mucous material remains centrally located, as in sebokeratinocytes of the apteric areas of avian skin. Some lipid and mucus is also incorporated into typical β‐cells of the outer scale surface, so that lipids are part of the fully keratinized hard keratin layer of the alligator. Lipids within β‐cells of outer scale surfaces and α‐cells of the hinge region are probably responsible for limiting water loss and ion movements across the skin. Neither typical mammalian keratohyalin granules nor lepidosaurian keratohyalin‐like granules were detected anywhere in alligator epidermis. The combination of anti‐β and anti‐α keratin antibodies revealed different distributions of β‐ and α‐keratins. In late embryonic stages (25–26 to hatching), β‐keratin occurs only in the upper suprabasal cells, in prekeratinized and keratinized layers, whereas α‐keratin bundles (tonofilaments) remain only in the lowest layers. The cross‐reactivity of the β‐antibody, produced against a chick scale keratin, further shows that avian and crocodilian hard (β) keratins share common antigenic sites, reflecting a phylogenetic affinity between these taxa.
Two generations of the tongue and gustatory organs in the development of Hynobius dunni Tago
Authors: Żuwała K. , Kato S. , Jakubowski M.
Published: March 2003

In the development of Hynobius dunni there are two consecutive generations of the tongue and two generations of gustatory organs (taste buds and taste disks). The anlage of the developing secondary tongue appears just in front of the free ending of the primary tongue beginning at the larval developmental stage 62. From stage 67, a gradual reduction in the anterior part of the gill skeleton that supports the primary tongue occurs as the developing secondary tongue replaces the primary one. The lining of the entire oropharyngeal cavity of larvae contains only gustatory organs of the taste bud (TB) type. In younger larvae, the sensory area of a TB has a diameter of between 10 and 13 µm, while in older larvae, TBs reach 16–18 µm in diameter. After metamorphosis, some gustatory organs in the secondary tongue with a sensory area of 26–36 µm in diameter appear. In older animals they may reach as much as 56–71 µm. In other regions of the oropharyngeal epithelium than the tongue, these organs have an ellipsoid shape with a major axis of about 50 µm. On the basis of the cytomorphological criteria established previously, these organs were designated as taste disks. Thus, the presence of two generations of gustatory organs is characteristic of some urodeles, as well as frogs.
Infectivity of the propagules associated with extraradical mycelia of two AM fungi following winter freezing
Authors: ADDY H. D. , MILLER M. H. , PETERSON R. L.
Published: March 2003

Abuscular mycorrhizal fungi are thought to survive adverse environmental conditions primarily as spores. Extraradical mycelia of two Glomus species were produced in fine mesh pouches which excluded roots but not hyphae. The mycelia in these pouches were exposed to freezing conditions, either in the field or in a controlled–temperature chamber. Bioassay plants were grown directly in the pouches and mycorrhizal colonization was assessed after 1 month. The mycelia remained infective in frozen soil over winter. This survival was not dependent on either the presence of root pieces or on the connection of mycelia to roots. Spores were not an effective inoculum in these bioassays. Overwinter survival of mycelia would enable plants to become incorporated into functional mycorrhizal associations early in spring.
Fructan and fructan‐metabolizing enzymes in the growth zone of barley leaves
Authors: ROTH ADRIAN , LÜSCHER MARCEL , SPRENGER NORBERT , BOLLER THOMAS , WIEMKEN ANDRES
Published: March 2003

To study the role of fructan in leaf development of barley seedlings, fructan contents and the activities of enzymes involved in fructan metabolism were measured in segments of the third leaf at the stage of maximal growth. Fructans amounted to more than 10% of the d. wt in the growth zone at the base of the developing leaf and decreased sharply in the zone above. The specific activities of sucrose∶sucrose 1‐fructosyltransferase (1‐SST) and sucrose∶fructan 6‐fructosyltransferase (6‐SFT), two key enzymes in fructan synthesis, also peaked in the growth zone but decreased more slowly in the zone above. By contrast, the specific activities of invertase and fructan exohydrolase (FEH) were low in the growth zone at the leaf base and had their peak just above it. The specific activity of fructan∶fructan 1‐fructosyltransferase (1‐FFT) was approx. constant over the whole leaf. These results indicate that transitory accumulation of fructans in the growth zone plays a key role in the development of barley leaves.
A comparative study of leaf nutrient concentrations in a regional herbaceous flora
Authors: THOMPSON KEN , PARKINSON JOHN A. , BAND STUART R. , SPENCER RITA E.
Published: March 2003

Mineral nutrient concentrations were determined in leaves of 83 mostly herbaceous species collected from central England. Most samples were analysed for N, P, K, Ca, Mg, Na, Fe, Al, Mn, Cu and Zn. Concentrations of K, N and P showed similar levels of interspecific variability, with the highest concentrations being 6–9 times the lowest. Mg and (especially) Ca were much more variable, with the highest concentrations being 24 and 49 times the lowest respectively. Only in the case of P concentration was the majority of the variance in the data found at or below the species level. Most of the variance in Ca and Mg concentrations was between monocots and dicots. Concentrations of N and P were strongly positively correlated with each other. Only Ca and Mn were consistently associated with soil pH, positively and negatively respectively. Dicots tended to accumulate more Ca and Mn from high soil concentrations than did monocots. Concentration of P was significantly positively correlated with maximum potential relative growth rate. Plants of woodland and arable habitats contained high concentrations of P, and those of pasture and skeletal habitats contained low concentrations of P. The P: N ratio was higher in plants of arable habitats. Species with P‐rich leaves tended to be currently increasing in abundance. The results suggest that plants with nutrient‐rich foliage grow quickly, dominate nutrient‐rich ecosystems and are generally increasing as a result of the eutrophication and disturbance arising from human exploitation.
Identification of four starch‐branching enzymes in barley endosperm: partial purification of forms I, IIa and IIb
Authors: SUN CHUANXIN , SATHISH P. , AHLANDSBERG STAFFAN , DEIBER ANNA , JANSSON CHRISTER
Published: March 2003

summary

Developing caryopses of barley (Hardeum vulgare L. ev. Golf) were monitored for starch‐branching enzyme activity for 1 month after anthesis. Homogenized caryopses from grains with the highest specific activity were used as starting material for purification of branching enzyme by FPLC chromatography. Several branching enzyme activity fractions were resolved. We have previously described the isolation of a 51/50 kDa protein with starch branching activity from one of these fractions. From three other fractions, we have now partially purified starch branching enzymes corresponding to forms I, IIa and IIb.
Identification of cultivar‐specific leghaemoglobin components in Pisum sativum
Authors: ULRICH KRISTINA , LENTZSCH PETER , SEYFARTH WOLFGANG
Published: March 2003

summary

The components of leghaemoglobin (Lb) from twelve different Pisum sativum L. cvs and three near‐isogenic foliar mutants were investigated by anion‐exchange high‐performance liquid chromatography (HPLC). Five different Lb component profiles could he found. The number of components varied from four to six dependent on cultivar used. An Lb pattern composed of four Lb components could be detected in thirteen P. sativum cultivars and lines. Ten of them showed an identical profile. In nodules of each cultivar, the two known major components, LbI and LbV, but also LbIV, could be detected. Additionally, cultivar‐specific Lb components could be identified, each representing up to 10%, of total Lb. One of these components, LbIII, has been described previously, but three new Lb components (LbII, LbVI, and LbVII) were found. The presence of all Lb components detected by HPLC was confirmed by analytical isoelectric focusing. Further, it was shown that age‐dependent changes in the relative concentrations of LbI and LbV are common in P. sativum and that these variations are independent of breeding lines and cultivars.
The occurrence of crassulacean acid metabolism among vascular epiphytes from Central Panama
Authors: ZOTZ G. , ZIEGLER H.
Published: March 2003

summary

The occurrence of crassulacean acid metabolism (CAM) among the epiphyte flora of the lowland forest on Barro Colorado Island (BCJ), Panama, was investigated. A total of 116 species was included, i.e. about 2/3 of the known epiphyte taxa. As judged from the carbon isotope ratios and the absence of Kranz anatomy, indications of CAM were found in 29 species of three families, Orchidaceae (20), Bromeliaceae (7), and Cactaceae (2). We estimate that about 25% of the epiphyte flora of BCI are CAM plants. CAM was most prevalent in exposed sites, but even in the understorey two epiphyte species engage in CAM.
Partitioning of 14C‐labelled photosynthate to developing nodules and roots of soybean (Glycine max)
Authors: HACIN JANEZ I. , BOHLOOL B. BEN , SINGLETON PAUL W.
Published: March 2003

summary

A split‐root growth system was used to study photosynthate partitioning to developing nodules and roots of soybean (Glycine max L., Merr). Opposite sides of the root systems were inoculated with Bradyrhizobium japonicum at 8 and 12 d after planting (early/delayed inoculation treatment) or, alternatively, only one side was inoculated 8 d after planting (early/uninoculated treatment). Plants were incubated with 14CO2 at 24‐h intervals from early inoculation until the onset of N2 fixation (acetylene reduction). After staining with Eriochrome black, root and nodule meristematic structures were excised under a dissecting microscope and their radioactivity determined by scintillation counting. The specific radioactivity of nodule structures increased with nodule development, and was as much as 4 times higher in early nodules than in roots and nodules on half‐roots receiving delayed inoculation By the time that N2 fixation could be measured in the first mature nodules, the early inoculated half‐root contained over 70% of the radioactivity recovered from the entire root systems of both early/delayed and early/uninotulated treatments. These results suggest that developing nodules create a strong sink for photosynthate, and that nodules and roots compete for current photosynthate. Early initiated nodules might develop at the expense of late initiated nodules, as well as at the expense of the roots themselves.
Genetic analysis and physiology of a trait for enhanced K+/Na+ discrimination in wheat
Authors: GORHAM J. , BRIDGES J. , DUBCOVSKY J. , DVORAK J. , HOLLINGTON P. A. , LUO M.‐C. , KHAN J. A.
Published: March 2003

summary

Variation for K+ and Na+ accumulation at low salinities in hydroponic (water) culture were observed in shoots of different wheat species. Greater discrimination (in favour of K+ and against Na+ accumulation) was shown by hexaploid bread wheat (Triticum aestivum L.) than by tetraploid durum wheat (T. turgidum L.). Since Aegilops tauschii Cosson (A. squarrosa L.), the source of the D genome in bread wheat, also exhibited high discrimination between K+ and Na+, it was concluded that the character resided in the D genome. Studies of aneuploid bread wheat lines and disomic substitution lines of D genome chromosomes for their A and B genome homoeologues in durum wheat cv. Langdon revealed that the trait was controlled by the long arm of chromosome 4D. Since the aneuploid and disomic substitution lines showed better relative salt tolerance than durum wheat, but had lower yield potentials, we recombined chromosome 4D with chromosome 4B in a tetraploid wheat background using a homoeologous pairing mutant. This produced families of 4D/4B recombinant lines, some of which exhibited the enhanced K+/Na+ discrimination trait. RFLP analysis confirmed that the trait was controlled by a single gene (Kna1) which was completely linked to five markers on the distal third of the long arm of 4D. A second cycle of homoeologous recombination was employed to remove the distal 4D genetic material from the recombined Kna1 4B/4D chromosome and to map Kna1 in greater detail. By this strategy, Kna1 was mapped within a short 2 cM region. Genetic analysis of K+: Na+ ratios showed very high LOD scores in this region for plants grown in solution culture, but lower values for plants grown in the field.

In general, recombinant lines which exhibited the enhanced K+/Na+ trait were slightly more tolerant of salinity in the field and in sand culture than recombinants lacking the trait. There was, however, considerable variation between individual lines. Ion discrimination and relative tolerance were also higher in a Kna1 recombinant (line no. R3) than in a kna1 recombinant (line no. R165) in sodic conditions. In these two lines the enhanced K+/Na+ discrimination trait did not alter responses to low potassium or calcium supply.
Introgression of salt‐tolerance genes from Thinopyrum bessarabicum into wheat
Authors: KING IAN P. , FORSTER BRIAN P. , LAW COLIN C. , CANT KAREN A. , ORFORD SIMON E. , GORHAM JOHN , READER STEVE , MILLER TERRY E.
Published: March 2003

summary

Salt‐affected soil is a major problem and has led to large areas of the earth's surface being unable to support agriculture. Wheat is not tolerant to high levels of salt; however, a number of its wild relatives, in particular Thinopyrum bessarabicum Savul. and Rayss, which grows on the Black Sea shore in the Crimea, are tolerant to high levels of NaCl. Thus the introgression of genes conferring salt tolerance from Th. bessarabicum into Triticum aestivum is one way in which salt‐tolerant wheat varieties can be produced. This paper reviews the progress made in developing salt‐tolerant wheat carrying Th. bessarabicum genes and salt‐tolerant wheat/Th. bessarabicum amphiploids.
Growth and development of Mesembryanthemum crystallinum (Aizoaceae)
Authors: ADAMS PATRICIA , NELSON DON E. , YAMADA SHIGEHIRO , CHMARA WENDY , JENSEN RICHARD G. , BOHNERT HANS J. , GRIFFITHS HOWARD
Published: March 2003

This review describes the life cycle of Mesembryantheum crystallinum L. (the common ice plant, Aizoaceae, Caryophyllales), a halophyte with a developmentally programmed switch from C3 photosynthesis to Crassulacean acid metabolism (CAM) which is accelerated by salinity and drought. Since there has been controversy regarding the interplay between genes and environmental stimuli during the development of M. crystallinum, it is timely to summarize the life cycle for a defined set of conditions. We seek to establish the framework whereby five stages of development can be described in terms of morphology, physiology, and molecular biology. Stages 1 and 2, representing germination and growth of a juvenile form, show a determinate pattern of growth. Although specific genes for salt tolerance can be induced at these stages, stress early in development prevents progression to the mature form (stages 3–5) in which the plants advance to mature growth, flowering, and seed development. Growth in stage 3 is indeterminate in the absence of stress, but development and flowering are accelerated by environmental stresses, and CAM is constitutively expressed. Depending on the severity of the stress, plants start to flower (stage 4) and then die from the roots, ultimately with only seed capsules remaining viable, with salt sequestered into large epidermal bladder cells (stage 5). We highlight responses to salinity leading to compartmentation of ions and compatible solutes, turgor maintenance, and CAM. Finally, the molecular genetics of the ice plant are characterized, emphasizing selected genes and their products. We conclude with an analysis of the multiple stages of growth as an ecological adaptation to progressive stress. The initial determinate and inflexible juvenile phase provides a critical mass of plant material which supports the indeterminate, mature phase. Depending on the degree of stress, the mature form is then propelled towards flowering and seedset.

CONTENTS

Summary
171

I.
Introduction
172

II.
Standardizing methodology
173

III.
Growth and development
175

IV.
Effects of salt stress on developmental physiology
176

V.
Ionic composition of cells during development
179

VI.
Water transport within the plant
179

VII.
The switch from C3 to Crassulacean Acid Metabolism
181

VIII.
Stress and plant‐growth regulators
182

IX.
Molecular biology
183

X.
Genetics, ploidy and mutants
184

XI.
Conclusions and future directions
185

Acknowledgements
187

References
187
Consequences of high loads of nitrogen for spruce (Picea abies) and beech (Fagus sylvatica) forests
Authors: RENNENBERG HEINZ , KREUTZER KARL , PAPEN HANS , WEBER PAUL
Published: March 2003

High loads of nitrogen to spruce and beech forests can result in a complete inhibition of NO3− uptake by the roots of the trees. This conclusion is based on (a) a comparison of a field site continuously exposed to high loads of N and a N‐limited site, (b) the results of N fertilization of a N‐limited field site, and (c) laboratory experiments under controlled environmental conditions. From fertilization experiments in the field it appears that NH4+ uptake might become inhibited subsequent to an excessive uptake of NH4+. Apparently, the inhibition of NO3− uptake by high loads of N to forests is a consequence of an accumulation of organic amino compounds in the roots originating from phloem transport from the shoot to the roots. These amino compounds seem to signal the N demand of the shoot to the roots. At present this function cannot be attributed to an individual organic amino compound in beech or spruce, but Gln is a likely candidate in both species among other compounds, e.g. Glu in spruce or Asp in beech trees. Direct inhibition of NO3− uptake by NH4+ can be excluded from the present studies. The mechanism(s) by which elevated levels of particular organic amino compounds interact with NO3− uptake remains to be elucidated. This (these) mechanism(s) seem to affect NO3− influx rather than NO3− efflux. As a consequence of this (these) mechanism(s), spruce and beech trees can prevent, within a certain physiological window, N over‐nutrition when the roots are exposed to excessive amounts of inorganic N. However, inhibition of NO3− and NH4+ uptake by the roots makes more N available for leaching into the ground water and, in addition, for soil microbial processes that result in the production and re‐emission of volatile N compounds into the atmosphere.

At the ‘Höglwald’ site, continuously exposed to high loads of N, >20% of the N input from throughfall into the spruce and beech plots is re‐emitted as NO and N2O. However, the NO to N2O ratio is highly dependent on the tree species, with a preference for NO in the spruce and a preference for N2O in the beech plot. Since at least part of the NO emitted from the soil will be converted inside the canopy in the presence of ozone to NO2 that might then be absorbed by the leaves, the portion of the N in the throughfall that will be released from the forest by gaseous N emission is higher in the beech than in the spruce plot. Leaching of NO3− into the ground water is high in the spruce, but minute in the beech plot. However, this positive effect of beech on ground water quality is achieved at the expense of an enhanced release of radiatively active N gases into the troposphere.
Localization of Fe‐containing superoxide dismutase in cyanobacteria from the Baltic Sea: depth and light dependency
Authors: CANINI A. , ALBERTANO P. , CAIOLA M. GRILLI
Published: March 2003

The abundance and cellular location of Fe‐containing superoxide dismutase (Fe‐SOD) in trichomes of Nodularia, Aphanizomenon and Anabaena collected from various depths in the Baltic Sea, and in trichomes of a cultured Nodularia strain, BC Nod‐9427, isolated from the Baltic Sea, was examined by immunogold labelling. For trichomes collected from natural populations the areal concentration of Fe‐SOD labelling decreased with depth: trichomes collected from surface accumulations had between 8 and 11 gold particles μm−2 whereas trichomes collected from a depth of 18 m were unlabelled. When trichomes collected from a depth of 10 m (mean areal labelling density 0·5 gold particles μm−2) were exposed to the higher irradiances present at 1 m, the areal concentration of Fe‐SOD increased to 3·5–4 gold particles μm−2 within 4 h. When cultures of Nodularia strain BC Nod‐9427, adapted to low light (10 μmol m−2 s−1), were transferred to an incident irradiance of 1350 μmol m−2 s−1, a doubling of the areal concentration of Fe‐SOD gold label was observed within 1 h. Addition of 3‐(3,4‐dichlorophenyl)‐1,1′‐dimethylurea (DCMU) to cultures immediately before their transfer to increased illumination resulted in a decrease in areal Fe‐SOD concentrations whereas addition of CdCl2 caused an increase over and above that induced by the elevated irradiance. These results suggest that Baltic Sea cyanobacteria are able to modulate their Fe‐SOD content but that this might be in response to oxidative stress rather than to light per se.
Molecular analysis of Gigaspora (Glomales, Gigasporaceae)
Authors: BAGO BERTA , BENTIVENGA STEPHEN P. , BRENAC VIRGINIE , DODD JOHN C. , PICHÉ YVES , SIMON LUC
Published: March 2003

This work presents a cooperative effort to integrate new molecular (isozyme and SSU analyses) characters into the morphological taxonomy of the genus Gigaspora (Glomales). Previous analyses of published Gigaspora SSU sequences indicated the presence of a few polymorphic nucleotides in the region delimited by primers NS71‐SSU 1492′. In our study, the SSU of 24 isolates of arbuscular mycorrhizal (AM) fungi from the Gigasporaceae were amplified and the NS71‐SSU 1492′ region was directly sequenced. The corresponding sequences of four more isolates of AM fungi from Gigasporaceae, already published, were also included in our analyses. Three Gigaspora groups were identified on the basis of a 6 nucleotide‐long ‘molecular signature’: Gigaspora rosea group (G. rosea+G. albida), Gigaspora margarita group (G. margarita+G. decipiens) and Gigaspora gigantea, which constituted a group by itself. The isozyme profiles (malate dehydrogenase, MDH) of 12 of these 28 isolates, and seven other isolates not sequenced, were compared. The results obtained further supported the grouping of isolates provided by the SSU analysis. Both SSU and MDH analysis indicated that two out of the 35 isolates had been misidentified, which was confirmed when their morphology was reassessed. The use of the Gigaspora intrageneric molecular signature as a quick, unambiguous and objective method to recognize Gigaspora isolates under any (field or laboratory) experimental conditions is suggested.