Rubiaceae
Crassulaceae
Spatial analysis of archaeal community structure in grassland soil. (1/7)
The complex structure of soil and the heterogeneity of resources available to microorganisms have implications for sampling regimens when the structure and diversity of microbial communities are analyzed. To assess the heterogeneity in community structure, archaeal communities, which typically contain sequences belonging to the nonthermophilic Crenarchaeota, were examined at two contrasting spatial scales by using PCR-denaturing gradient gel electrophoresis (DGGE) analysis followed by unweighted pair group method with arithmetic mean analysis of 16S rRNA- and ribosomal DNA-derived profiles. A macroscale analysis was carried out with soil cores taken at 2-m intervals along triplicate 8-m transects from both managed (improved) and natural (unimproved) grassland rhizosphere soils. A microscale analysis was carried out with a single soil core by assessing the effects of both sample size (10, 1, and 0.1 g) and distance between samples. The much reduced complexity of archaeal profiles compared to the complexity typical of the bacterial community facilitated visual comparison of profiles based on band presence and revealed different levels of heterogeneity between sets of samples. At the macroscale level, heterogeneity over the transect could not be related to grassland type. Substantial heterogeneity was observed across both improved and unimproved transects, except for one improved transect that exhibited substantial homogeneity, so that profiles for a single core were largely representative of the entire transect. At the smaller scale, the heterogeneity of the archaeal community structure varied with sample size within a single 8- by 8-cm core. The archaeal DGGE profiles for replicate 10-g soil samples were similar, while those for 1-g samples and 0.1-g samples showed greater heterogeneity. In addition, there was no relationship between the archaeal profiles and the distance between 1- or 0.1-g samples, although relationships between community structure and distance of separation may occur at a smaller scale. Our findings demonstrate the care required when workers attempt to obtain a representative picture of microbial community structure in the soil environment. (+info)Mechanical adaptations of cleavers (Galium aparine). (2/7)
BACKGROUND AND AIMS: Cleavers (Galium aparine) is a fast-growing herbaceous annual with a semi-self-supporting, scrambling-ascending growth habit. Mature plants often use upright species for support. It is common in hedgerows and on waste ground. This study aims to characterize the mechanical behaviour of the stem and roots of cleavers and relate this to the arrangement of structural tissue, the net microfibrillar orientations in the cell walls, and plant growth habit. METHODS: The morphology and mechanics of mature cleavers was investigated using plants grown in pots and ones collected from the grounds at the University of Lincoln, Lincoln, UK. Tensile tests were carried out on the stem and the basal section of the first-order lateral roots. The net orientation of cellulose microfibrils in the cell walls was investigated using polarized light microscopy. KEY RESULTS: Results show that the basal regions of the stem and first-order lateral roots were highly extensible. Breaking strains of 24 +/- 7% were recorded for the stem base and 28 +/- 6% for the roots. Anatomical observations showed that the lower stem (base + 100 mm) was circular in cross-section with a solid central core of vascular tissue, whereas further up the stem the transverse section showed a typical four-angled shape with a ring-like arrangement of vascular tissue and sclerenchyma bundles in the corners. The net orientation of wall microfibrils in the secondary xylem diverges from the longitudinal by between 8 and 9 degrees . CONCLUSIONS: The basal region of the stem of cleavers is highly extensible, but the mechanism by which the stem is able to withstand such high breaking strains is unclear; reorientation of the cellulose fibrils in the stem along the axis of loading is not thought to be responsible. (+info)Indole-3-acetic acid and auxin herbicides up-regulate 9-cis-epoxycarotenoid dioxygenase gene expression and abscisic acid accumulation in cleavers (Galium aparine): interaction with ethylene. (3/7)
Interaction between auxin and auxin-induced ethylene was suggested in previous work to up-regulate abscisic acid (ABA) biosynthesis in cleavers (Galium aparine) through stimulated cleavage of xanthophylls to xanthoxin, catalysed by 9-cis-epoxycarotenoid dioxygenase (NCED). Here, the effects of auxin on NCED gene expression were studied in relation to changes in ethylene synthesis and ABA levels. A gene from G. aparine shoot tissue was cloned based on sequence similarity to cloned NCED genes from tomato (LeNCED1), potato, Phaseolus, and Arabidopsis. When the roots of G. aparine plants were treated with 0.5 mM indole-3-acetic acid (IAA), IAA concentrations increased from 0.2 microM to 65 microM IAA in the shoot tissue after 3 h. Transient increases in GaNCED1 mRNA levels were detectable as early as 1 h after treatment and reached maximum values of 40-fold, relative to the control, after 3 h. Increases in GaNCED1 mRNA preceded increases in 1-aminocyclopropane-1-carboxylic acid and ethylene. Levels of ABA began to increase more slowly and, significantly, with a lag phase of 2 h, and reached levels 24-fold higher than those in controls after 24 h. GaNCED1 gene expression was also stimulated by auxin herbicides. The ethylene-releasing compound ethephon induced GaNCED1 transcript levels only moderately. In accordance with this, aminoethoxyvinylglycine and cobalt ions, which inhibit ethylene synthesis, only slightly affected the increase in GaNCED1 transcript levels by IAA. However, both ethylene inhibitors decreased IAA-induced ABA accumulation by up to 70%. This suggests that auxin and auxin-induced ethylene are involved in ABA accumulation. While auxin is the primary trigger for NCED gene expression, ethylene appears to enhance ABA biosynthesis, possibly by up-regulation of NCED activity post-transcriptionally. (+info)Always on the bright side: the climbing mechanism of Galium aparine. (4/7)
(+info)Climbing plants: attachment and the ascent for light. (5/7)
(+info)Indigenous arbuscular mycorrhizal fungal assemblages protect grassland host plants from pathogens. (6/7)
(+info)Mechanics of plant fruit hooks. (7/7)
(+info)"Galium" is a genus of plants, and it does not have a specific medical definition. However, some species of Galium are used in herbal medicine. For instance, Cleavers (Galium aparine) is used as a diuretic and to treat skin problems, while Lady's Bedstraw (Galium verum) has been used for treating inflammation and kidney disorders. It is important to note that the use of herbal remedies should always be discussed with a healthcare provider before starting any new treatment.
Rubiaceae is not a medical term, but a taxonomic category in botany. It refers to the family of flowering plants that includes more than 13,500 species, distributed across approximately 600 genera. Some well-known members of this family include coffee (Coffea arabica), gardenias (Gardenia jasminoides), and madder (Rubia tinctorum).
In a medical context, certain plants from the Rubiaceae family have been used in traditional medicine for various purposes. For example:
* Coffee (Coffea arabica) beans are used to prepare caffeinated beverages that can help with alertness and concentration.
* Gardenia fruits and flowers have been used in traditional Chinese medicine to treat anxiety, insomnia, and inflammation.
* Madder root (Rubia tinctorum) has been used as a dye and in traditional medicine to treat skin conditions and digestive disorders.
However, it's important to note that the medicinal use of plants from this family should be based on scientific evidence and under the guidance of healthcare professionals, as some of these plants can have side effects or interact with medications.
Crassulaceae is a family of succulent plants, also known as stonecrops or orpines. These plants are characterized by their thick, fleshy leaves that store water, allowing them to survive in dry environments. They are native to various parts of the world, including Europe, Africa, and Asia. Some common examples of Crassulaceae include Sedum species (such as Sedum spectabile and Sedum telephium), Sempervivum species (also known as hens and chicks), and Echeveria species. These plants are often grown as ornamentals for their attractive foliage and flowers.
"Urtica dioica," also known as stinging nettle, is a plant species native to Europe, Asia, North Africa, and North America. While it doesn't have a formal medical definition, it is widely used in herbal medicine. The leaves and stems of the plant contain various compounds, including histamine, acetylcholine, serotonin, and forms of nitrogen like formic acid, which can cause a stinging sensation when they come into contact with human skin.
In medical contexts, Urtica dioica extracts are sometimes used to treat conditions such as allergies, joint pain, and urinary tract infections. However, it's important to note that the scientific evidence supporting these uses is generally limited, and more research is needed to confirm their effectiveness and safety. As with any medical treatment or supplement, individuals should consult with a healthcare provider before using Urtica dioica for therapeutic purposes.