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Leaf Base (leaf + base)
Selected AbstractsTransgenic maize lines with cell-type specific expression of fluorescent proteins in plastidsPLANT BIOTECHNOLOGY JOURNAL, Issue 2 2010Amir Sattarzadeh Summary Plastid number and morphology vary dramatically between cell types and at different developmental stages. Furthermore, in C4 plants such as maize, chloroplast ultrastructure and biochemical functions are specialized in mesophyll and bundle sheath cells, which differentiate acropetally from the proplastid form in the leaf base. To develop visible markers for maize plastids, we have created a series of stable transgenics expressing fluorescent proteins fused to either the maize ubiquitin promoter, the mesophyll-specific phosphoenolpyruvate carboxylase (PepC) promoter, or the bundle sheath-specific Rubisco small subunit 1 (RbcS) promoter. Multiple independent events were examined and revealed that maize codon-optimized versions of YFP and GFP were particularly well expressed, and that expression was stably inherited. Plants carrying PepC promoter constructs exhibit YFP expression in mesophyll plastids and the RbcS promoter mediated expression in bundle sheath plastids. The PepC and RbcS promoter fusions also proved useful for identifying plastids in organs such as epidermis, silks, roots and trichomes. These tools will inform future plastid-related studies of wild-type and mutant maize plants and provide material from which different plastid types may be isolated. [source] Thermographic visualization of cell death in tobacco and ArabidopsisPLANT CELL & ENVIRONMENT, Issue 1 2001L. Chaerle ABSTRACT Pending cell death was visualized by thermographic imaging in bacterio-opsin transgenic tobacco plants. Cell death in these plants was characterized by a complex lesion phenotype. Isolated cell death lesions were preceded by a colocalized thermal effect, as previously observed at sites infected by tobacco mosaic virus (TMV) (Chaerle et al. 1999Nature Biotechnology 17, 813,816). However, in most cases, a coherent front of higher temperature, trailed by cell death, initiated at the leaf base and expanded over the leaf lamina. In contrast to the homogenous thermal front, cell death was first visible close to the veins, and subsequently appeared as discrete spots on the interveinal tissue, as cell death spread along the veins. Regions with visible cell death had a lower temperature because of water evaporation from damaged cells. In analogy with previous observations on the localized tobacco,TMV interaction (Chaerle et al. 1999), the kinetics of thermographic and continuous gas exchange measurements indicated that stomatal closure preceded tissue collapse. Localized spontaneous cell death could also be presymptomatically visualized in the Arabidopsis lsd2 mutant. [source] Multivariate analysis of leaf shape patterns in Asian species of the Uvaria group (Annonaceae)BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2003CONOR MEADE Multivariate analysis of leaf radian measurements was used to investigate variation in leaf shape among 34 Asian species of the Uvaria group, a large palaeotropical group of climbing Annonaceae characterized by imbricate petals and stellate hairs. Raw data were normalized by conversion into 15 ratio characters and using the log10 transformation. All species surveyed showed a unique leaf-shape ,bauplan'. The ratio character with the greatest discriminating power in both the Principal Components Analysis and Discriminant Analysis (DA) results was a measure of the shape of the leaf base. Ratio characters with the highest factor loadings for principal components 1 and 2 clearly separated the sampled taxa when plotted against one another and provided support for the retention of several taxa as distinct species or varieties. Classification of cases into taxa using DA yielded a correct classification rate of only 52% for the ratio-transformed data; however, division of taxa in the dataset into smaller subgroups defined by discrete morphological characters significantly increased the accuracy of case identification to between 67 and 100% of cases correctly classified, depending on the group. Case identification using DA on log10 -transformed data was higher than for the ratio values in the entire dataset (61.7%) and the larger subgroups. However, the rate of correct case assignment was lower in the smaller groups than for the ratio data. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 143, 231,242. [source] Adult large pine weevils Hylobius abietis feed on silver birch Betula pendula even in the presence of conifer seedlingsAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2006Riitta Toivonen Abstract 1,The feeding preference of the adult pine weevil Hylobius abietis (L.) (Coleoptera: Curculionidae) for Betula pendula Roth was studied in no-choice and paired-choice feeding experiments. 2,In the first no-choice test, large quantities of silver birch bark in Petri dishes were consumed; on average, the daily consumption of each weevil was 67 mm2. 3,In the second no-choice test, the weevils were offered 1-year-old silver birch seedlings for 6 days. Initially, the weevils fed mostly on the stem bases; later, they moved upward to feed on other parts of the stems. In addition to the main shoots, scars caused by gnawing were also found on leaf bases, blades, veins and petioles. Feeding resulted in the death of the main stems in 15% of the seedlings. 4,In the paired-choice tests, the conifers were preferred to silver birch, even though a large amount of silver birch was also consumed in the presence of conifers. 5,In the paired-choice tests, equal amounts of Scots pine and Norway spruce were always consumed. When hybrid aspen was offered, only small amounts were gnawed. [source] Food mechanical properties in three sympatric species of Hapalemur in Ranomafana National Park, MadagascarAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Nayuta Yamashita Abstract We investigated mechanical dietary properties of sympatric bamboo lemurs, Hapalemur g. griseus, H. aureus, and H. (Prolemur) simus, in Ranomafana National Park, Madagascar. Each lemur species relies on bamboo, though previous behavioral observations found that they specialize on different parts of a common resource (Tan: Int J Primatol 20 1999 547,566; Tan: PhD dissertation 2000 State University of New York, Stony Brook). On the basis of these earlier behavioral ecology studies, we hypothesized that specialization on bamboo is related to differences in mechanical properties of specific parts. We quantified mechanical properties of individual plant parts from the diets of the bamboo lemur species using a portable tester. The diets of the Hapalemur spp. exhibited high levels of mechanical heterogeneity. The lemurs, however, could be segregated based on the most challenging (i.e., mechanically demanding) foods. Giant bamboo culm pith was the toughest and stiffest food eaten, and its sole lemur consumer, H. simus, had the most challenging diet. However, the mechanical dietary properties of H. simus and H. aureus overlapped considerably. In the cases where lemur species converged on the same bamboo part, the size of the part eaten increased with body size. Plant parts that were harvested orally but not necessarily masticated were the most demanding, indicating that food preparation may place significant loads on the masticatory apparatus. Finally, we describe how mechanical properties can influence feeding behavior. The elaborate procurement processes of H. simus feeding on culm pith and H. griseus and H. aureus feeding on young leaf bases are related to the toughnesses of protective coverings and the lemurs' exploitation of mechanical vulnerabilities in these plants. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Developmental morphology of Saxicolella amicorum and S. submersa (Podostemaceae: Podostemoideae) from GhanaBOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2002K. GABRIEL AMEKA Saxicolella (six spp.) is a podostemoid genus occurring in tropical west Africa (Cameroon, Ghana, Nigeria). Taxonomically used characters such as root (with holdfasts), pollen (dyads in many Podostemoideae), capsules (with ribs) and seeds are demonstrated and discussed. This paper deals with the structure and development of two species, which are endemic to rivers in southern Ghana: Saxicolella amicorum J.B.Hall and Saxicolella submersa (J.B.Hall) C.D.K.Cook & Rutish. (syn. Polypleurum submersum J.B.Hall).,Saxicolella amicorum has simple, one-flowered stems up to 3 cm long, whereas S. submersa has branched, many-flowered stems up to 25 cm long. Vegetative shoots can reach 12 cm (S. amicorum) and even 50 cm (S. submersa) in length. The latter species was previously placed in the Asian genus Polypleurum because the long floating axis was misinterpreted as a root which would be typical for Polypleurum. The long floating axis of S. submersa develops exogenous leaves and is actually a stem. Both S. amicorum and S. submersa have various features in common: vegetative parts (roots, stems, leaves) are elongate and very thin (diameter less than 1 mm); prostrate roots are narrow ribbons (twice as wide as thick); endogenous shoots in opposite pairs along the root; leaves usually simple and filiform; leaf bases with two attached ear-like stipules; spathella club-shaped to ellipsoidal; erect flowers with a solitary stamen; ovary ellipsoidal to fusiform, bilocular; capsules nearly isolobous, with three prominent ribs per valve (i.e. eight ribs per capsule including sutural ribs). Evolutionary dynamics of the root structures in African Podostemoideae such as Saxicolella include: formation of green prostrate ribbons as a result of dorsoventral root flattening; reduction of root caps; occurrence of adhesive hairs and exogenous holdfasts which are disk- or finger-like. Structural diversity and developmental patterns in the Ghanaian Saxicolella species are compared with other African Podostemoideae. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 139, 255,273. [source] | ||||||||||