Home About us Contact
|
Home About us Contact | ||
|
|
||
Plantago Major (plantago + major)
Selected AbstractsLocalization of deposited polycyclic aromatic hydrocarbons in leaves of PlantagoENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Martine I. Bakker Abstract After deposition to foliage, polycyclic aromatic hydrocarbons (PAHs) may remain on the leaf surface, accumulate in the cuticular wax, or diffuse into the remaining interior of the plant. In a field study, the location of deposited PAHs in the leaves of two Plantago species was determined. To this aim, leaves of Plantago major and Plantago media were divided into three fractions. First, the leaves were washed (wash-off fraction), then cuticular wax was extracted (wax fraction). Finally, the remaining leaf material was extracted (interior fraction). The presence of PAHs could be demonstrated in all three fractions. For both plants, the distribution of PAHs over the three fractions changed with molecular weight (mol wt) of the PAHs. The wash-off fraction increased with increasing molecular weight, likely because high molecular-weight PAHs occur predominantly bound to particles, which can be readily washed off from the leaves. In contrast, the amount of PAHs detected in the interior of the leaves decreased with increasing molecular weight. This can be explained by a slow desorption of the PAHs from the particles and a low diffusion rate of the larger molecules. This study shows that washing reduces the amount of high molecular-weight PAHs on plant surfaces. Therefore, washing of leafy vegetables is important to minimize human dietary intake of PAHs. [source] Isolation of polymorphic microsatellite loci in Plantago major and P. intermediaMOLECULAR ECOLOGY RESOURCES, Issue 3 2001J. Squirrell Abstract Plantago major and P. intermedia are two closely related inbreeding species. The isolation of polymorphic codominant microsatellite markers will provide valuable tools to investigate the reproductive isolation and the evolution of the two species. The isolation of microsatellite loci was achieved using a membrane enrichment method. Primers were designed to microsatellite flanking sequences and were analysed using fluorescent labels. Results indicated that nine out of the 10 loci amplified in both species, and that all the loci were polymorphic. The amplification of the loci was tested in a variety of Plantago species and was shown to be limited. [source] Limitations to CO2 assimilation in ozone-exposed leaves of Plantago majorNEW PHYTOLOGIST, Issue 1 2002Y. Zheng Summary ,,The potential limitations on net leaf carbon assimilation imposed by stomatal conductance, carboxylation velocity, capacity for ribulose 1,5-bisphosphate regeneration and triose phosphate ultilization rate were derived from steady-state gas exchange measurements made over the life-span of two leaves on plants of an ,O3 -sensitive' population of Plantago major grown at contrasting atmospheric O3 concentrations. ,,Parallel measurements of chlorophyll fluorescence were used to monitor changes in the quantum efficiency of PSII photochemistry, and in vitro measurements of Rubisco activity were made to corroborate modelled gas exchange data. ,,Data indicated that a loss of Rubisco was predominantly responsible for the decline in CO2 assimilation observed in O3 -treated leaves. The quantum efficiency of PSII was unchanged by O3 exposure. ,,Stomatal aperture declined in parallel with CO2 assimilation in O3 -treated plants, but this did not account for the observed decline in photosynthesis. Findings suggested that O3 -induced shifts in stomatal conductance result from ,direct' effects on the stomatal complex as well as ,indirect effects' mediated through changes in intercellular CO2 concentration. Leaves on the same plant exposed to equivalent levels of O3 showed striking differences in their response to the pollutant. [source] Immunolocalization of the PmSUC1 Sucrose Transporter in Plantago major Flowers and Reporter-Gene Analyses of the PmSUC1 Promoter Suggest a Role in Sucrose Release from the Inner IntegumentPLANT BIOLOGY, Issue 3 2007C. Lauterbach Abstract: This paper presents a detailed analysis of the PmSUC1 gene from Plantago major, of its promoter activity in Arabidopsis, and of the tissue specific localization of the encoded protein in Plantago. PmSUC1 promoter activity was detected in the innermost layer of the inner integument (the endothel) of Arabidopsis plants expressing the gene of the green fluorescent protein (GFP) under the control of the PmSUC1 promoter. This promoter activity was confirmed with a PmSUC1-specific antiserum that identified the PmSUC1 protein in the endothel of Plantago and of Arabidopsis plants expressing the PmSUC1 gene under the control of its own promoter. PmSUC1 promoter activity and PmSUC1 protein were also detected in pollen grains during maturation inside the anthers and in pollen tubes during and after germination. These results demonstrate that PmSUC1 is involved in sucrose partitioning to the young embryo and to the developing pollen and growing pollen tube. In the innermost cell layer of the inner integument, a tissue that delivers nutrients to the endosperm and the embryo, PmSUC1 may catalyze the release of sucrose into the apoplast. [source] | ||||||||||