Biogenic volatile emissions from the soil PEÑUELAS, J; ASENSIO, D; THOLL, D ...
Plant, cell & environment/Plant, cell and environment,
August 2014, Letnik:
37, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Volatile compounds are usually associated with an appearance/presence in the atmosphere. Recent advances, however, indicated that the soil is a huge reservoir and source of biogenic volatile organic ...compounds (bVOCs), which are formed from decomposing litter and dead organic material or are synthesized by underground living organism or organs and tissues of plants. This review summarizes the scarce available data on the exchange of VOCs between soil and atmosphere and the features of the soil and particle structure allowing diffusion of volatiles in the soil, which is the prerequisite for biological VOC‐based interactions. In fact, soil may function either as a sink or as a source of bVOCs. Soil VOC emissions to the atmosphere are often 1–2 (0–3) orders of magnitude lower than those from aboveground vegetation. Microorganisms and the plant root system are the major sources for bVOCs. The current methodology to detect belowground volatiles is described as well as the metabolic capabilities resulting in the wealth of microbial and root VOC emissions. Furthermore, VOC profiles are discussed as non‐destructive fingerprints for the detection of organisms. In the last chapter, belowground volatile‐based bi‐ and multi‐trophic interactions between microorganisms, plants and invertebrates in the soil are discussed.
The emission of volatiles is a common, but mostly neglected, ability of bacteria that is important for inter‐ and intraspecific interactions. Currently, limited information is available on how the ...bacterial volatile (mVOC) signal is integrated into a plant's life at the physiological, transcriptional and metabolic level. Previous results provided evidence for volatile‐dependent regulation of WRKY18, a pathogen‐responsive transcription factor of Arabidopsis thaliana in co‐culture with two rhizobacteria, Serratia plymuthica HRO‐C48 and Stenotrophomonas maltophilia R3089.
Dual cultures of these bacteria and A. thaliana; application of the common mVOC 2‐phenyl‐ethanol; extraction of metabolites of A. thaliana after exposure to bacterial volatiles; and analysis of the metabolomes (GC‐TOF/MS) were carried out.
The prominent microbial aromatic compound 2‐phenyl‐ethanol, emitted by both bacteria, negatively affects growth of A. thaliana wild type, whereas WRKY18 T‐DNA insertion mutants were significantly more tolerant than wild‐type seedlings. This paper also demonstrates for the first time the impact of the rhizobacterial volatiles on the metabolome of A. thaliana. Upon mVOC exposure the plants rearrange their metabolism by accumulation of e.g. amino acids and TCA intermediates that potentially allow plants to cope with and survive this stress.
Our findings illustrate the high degree of complexity of metabolic rearrangements underlying the interactions of bacterial volatile elicitors and resulting plant responses. Furthermore, the impact of the volatile 2‐phenyl‐ethanol as a signal in the WRKY18‐dependent pathway highlights this compound as an important molecular player.
Methyl salicylate and methyl benzoate are components of many plant aromas and scents. The benzenoid carboxyl methyltransferases catalyze the last step of their synthesis. The MTs are structurally and ...biochemically characterized, expression properties as well as evolutionary aspects are summarized.
Benzenoid carboxyl methyltransferases synthesize methyl esters (e.g., methyl benzoate and methyl salicylate), which are constituents of aromas and scents of many plant species and play important roles in plant communication with the surrounding environment. Within the past five years, eleven such carboxyl methyltransferases were isolated and most of them were comprehensively investigated at the biochemical, molecular and structural level. Two types of enzymes can be distinguished according to their substrate preferences: the SAMT-type enzymes isolated from
Clarkia breweri,
Stephanotis floribunda,
Antirrhinum majus,
Hoya carnosa, and
Petunia hybrida, which have a higher catalytic efficiency and preference for salicylic acid, while BAMT-type enzymes from
A. majus,
Arabidopsis thaliana,
Arabidopsis lyrata, and
Nicotiana suaveolens prefer benzoic acid. The elucidation of
C. breweri SAMT’s three-dimensional structure allowed a detailed modelling of the active sites of the carboxyl methyltransferases and revealed that the SAM binding pocket is highly conserved among these enzymes while the methyl acceptor binding site exhibits some variability, allowing a classification into SAMT-type and BAMT-type enzymes. The analysis of expression patterns coupled with biochemical characterization showed that these carboxyl methyltransferases are involved either in floral scent biosynthesis or in plant defense responses. While the latter can be induced by biotic or abiotic stress, the genes responsible for floral scent synthesis exhibit developmental and rhythmic expression pattern. The nature of the product and efficiency of its formation in planta depend on the availability of substrates, the catalytic efficiency of the enzyme toward benzoic acid and/or salicylic acid, and the transcriptional, translational, and post-translational regulation at the enzyme level. The biochemical properties of benzenoid carboxyl methyltransferases suggest that the genes involved in plant defenses might represent the ancestor for the presently existing floral genes which during evolution gained different expression profiles and encoded enzymes with the ability to accept structurally similar substrates.
Expression of the light-harvesting complex protein genes (Lhc) is under the control of a circadian clock. To dissect the molecular regulatory components of the circadian clock a promoter deletion ...analysis of four tomato Lhc genes was performed in transgenic tobacco plants. The important 5'-upstream promoter regions are present at different positions relative to the transcription start site of Lhc b1*1, b1*2, Lhc a3 and Lhc a4. A short sequence of 47 nucleotides is necessary for conferring circadian Lhc mRNA oscillations. Sequence alignment of the specified promoter regions revealed a novel motif 'CAANNNNATC'. This motif is conserved in 5'-upstream regions of clock controlled Lhc genes and overlaps with a sequence relevant in phytochrome mediated gene expression.
In this study, we tested the effects of crude extracts from flax (Linum usitatissimum) on the production of estradiol and expression of estrogen receptor (ER) and progesterone receptor (PR) in human ...breast cancer MCF7 cells.
Isoflavone and lignan extracts from flax plant Linum usitatissimum were obtained, using different extraction methods. Breast carcinoma cells (MCF7) were incubated with various concentrations of the isolated extracts. Untreated MCF7 cells were used as controls. Supernatants were removed at designated times and tested for estradiol with an ELISA method. Furthermore, the effect of phytoestrogen extracts on the production of ERa and ERbeta as well as on PR was examined.
Production of estradiol is elevated in MCF7 cells in a concentration-dependent manner after stimulation with isoflavone and lignan extracts from Linum usitatissimum. Expression of ERalpha is up-regulated after stimulation with lower concentrations of lignan extracts from flax plants, unchanged at median concentrations and down-regulated at high concentrations. Expression of ERbeta is down-regulated in a concentration-dependent manner.
Abstract
The emission of fragrances can qualitatively and quantitatively differ in different parts of flowers. A detailed analysis was initiated to localize the floral tissues and cells which ...contribute to scent synthesis in STEPHANOTIS FLORIBUNDA (Asclepiadaceae) and NICOTIANA SUAVEOLENS (Solanaceae). The emission of scent compounds in these species is primarily found in the lobes of the corollas and little/no emission can be attributed to other floral organs or tissues. The rim and centre of the petal lobes of S. FLORIBUNDA contribute equally to scent production since the amount of SAMT (salicylic acid carboxyl methyltransferase) and specific SAMT activity compensate each other in the rim region and centre region. IN SITU immunolocalizations with antibodies against the methyl benzoate and methyl salicylate-synthesizing enzyme indicate that the adaxial epidermis with few subepidermal cell layers of S. FLORIBUNDA is the site of SAMT accumulation. In N. SUAVEOLENS flowers, the petal rim emits twice as much methyl benzoate due to higher total protein concentrations in the rim versus the petal centre; and, both the adaxial and abaxial epidermis house the BSMT (salicylic acid/benzoic acid carboxyl methyltransferase).
Phytoestrogens are a diverse group of nonsteroidal plant compounds which have similar effects to endogenous estrogens in humans and have been ascribed potential anticarcinogenic activities. We tested ...the effects of phytoestrogen extracts from different plant organs of flax, Linum usitatissimum, on cell proliferation in trophoblast tumour cells of the cell line Jeg3.
Phytoestrogen extracts were prepared from leaves, stems and roots of L. usitatissimum using different extraction methods. The isolated phytoestrogens were identified using HPLC-MS analysis. The influence on cell proliferation (MTT test) was determined in the trophoblast tumour cells, Jeg3.
Cell proliferation of trophoblast tumour Jeg3 cells was significantly affected by the phytoestrogens isolated from leaves, stems and roots of L. usitatissimum. Root extracts inhibited Jeg3 cell growth significantly.
A cell culture model system of the human trophoblast tumour cell line, Jeg3, was established to test the effect of potential phytoestrogens on cell proliferation. It was shown that the roots of L. usitatissimum contain measurable concentrations of lignans and isoflavones.
Phytoestrogens are naturally occurring, plant-derived, nonsteroidal phytochemicals with anticarcinogenic potential. The aim of this study was to isolate phytoestrogens from the flax root of Linum ...usitatissimum and to test their effect on cellular metabolism in the human mammalian carcinoma cell line MCF-7 using the Bionas 2500 analysis system.
Metabolically relevant parameters such as acidification, oxygen consumption and cell adhesion were registered continuously over 8 and 24 hours on six sensor chips in parallel at different concentrations of flax root extracts.
The extracts from flax roots of L. usitatissimum reduced extracellular acidification, respiration and adhesion in a concentration-dependent manner.
The Bionas 2500 analysis system allows multiparametric online monitoring of cellular processes and can be used to detect the mode of action of anticarcinogenic compounds in cellular metabolism.
The higher soy intake in the Asian population compared to Europeans is believed to be an essential factor for the lower incidence of hormone-dependent tumours in Asia. It has already been shown that ...soya beans, with their ingredients genistein and daidzein from the isoflavonoid group, have protective effects on hormone-caused diseases. Lignans are another, less investigated, group of phytoestrogens. The aim of this study was to investigate the effects of flax-seed, which is typically found in Northern European diets, on the proliferation and hormone production of an estrogen receptor (ER)-positive trophoblast tumour cell line.
Trophoblast tumour cells of the cell line Jeg3 were incubated with 2 different concentrations of the isolated crude extract of flax-seed and 7 chemically partitioned extract fractions. Untreated cells were used as controls. After 48 h of stimulation, cell proliferation was measured using the BrdU method. The concentrations of hCG and progesterone produced by the trophoblast tumour cells were measured 48 h after stimulation. Extract fractions with antiproliferative effects in the BrdU- test were analysed by HPLC-MS.
Our study showed an inhibitory influence of some of the isolated flax-seed fractions on the Jeg3 tumour cells. Proliferation of the Jeg3 cells was decreased by flax-seed fractions I, V, VI and VII in a dose-dependent manner. Inhibition of hCG production by flax-seed extracts III, V, VI and VII was also dose-dependent. Extract fractions V and VI decreased the production of progesterone by 58% to 86%. Some extract fractions showed a stimulating effect on hormone production and cell proliferation. HPLC-MS analysis showed the presence of matairesinol and biochanin A in flax-seed fraction VI.
Flax-seed seems to have similar inhibitory effects to soya on hormone production and proliferation of hormone-sensitive tumour cells. Our results showed a dose-dependent inhibition by isolated flax-seed extracts on the Jeg3 cell line. Matairesinol and biochanin A seem to be useful candidates for extended tests on other tumour cell lines and normal tissues to evaluate the potential benefit of a lignan-containing therapy in hormone-dependent diseases.
Aim and setting: To test the effects of crude extracts from flax (Linum usitatissimum) on progesterone and estradiol and ERα and β/PR production in choriocarcinoma cell lines Jeg 3 and BeWo. Tumor ...trophoblast cells (Jeg 3 and BeWo) were incubated in the presence of different concentrations of the flax crude extracts. Estradiol and progesterone production was measured. Estrogen receptor α and β as well as progesterone receptor expressions were also assessed. Results: In Jeg 3 cells, progesterone production was downregulated by flax root and leaves extract, while in BeWo cells only flax root extract did manage to downregulate progesterone production. ERβ expression was significantly downregulated by flax root and flax leaves extract in both cell lines; on the contrary, ERα expression was increased by flax leaves extract in BeWo cells. PR expression was downregulated by flax leaves extract in Jeg 3 and by flax root extract in BeWo cells. Conclusion: Flax extracts derived from leaves and especially from roots can modify progesterone and possibly estradiol production, while at the same time they seem to alter ERβ expression. Further studies on animal models and adequately designed retrospective epidemiological studies are imperative to clarify this role upon progesterone.
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