Inhibition and promotion of germination by several sesquiterpenes (original) (raw)
Related papers
Journal of chemical ecology, 2003
We compared the potential allelopathic activity of 47 monoterpenoids of different chemical groups, by estimating their effect on seed germination and subsequent growth of Lactuca sativa seedlings. Apart from individual compounds, eleven pairs at different proportions were also tested. As a group, the hydrocarbons, except for (+)-3-carene, were the least inhibitory. Of the oxygenated compounds, the least inhibitory were the acetates; whenever the free hydroxyl group of an alcohol turned into a carboxyl group, the activity of the resulting ester was markedly lower (against both germination and seedling growth). Twenty-four compounds were extremely active against seedling growth (inhibiting it by more than 85%), but only five against seed germination. The compounds that were most active against both processes belonged to the groups of ketones and alcohols; they were terpinen-4-ol, dihydrocarvone, and two carvone stereoisomers. We used a model to investigate whether compounds acted inde...
Seed Germination Inhibitors: Molecular and Phytochemical Aspects
International Journal of Applied Pharmaceutical Sciences and Research, 2018
Two major stages of seed development are dormancy and germination which finally promotes the growth of a plant. Some internal and external factors such as hormonal, genetic, chromatin development and environmental factors which maintain the seed dormancy with passing time and other suitable factors, these dormancy promoters are gradually decreased causing release of dormancy and promoting germination by the mechanisms of ROS in plant signalling, cell elongation and reverse mobilization. But dormancy has some benefits in protecting the seed from extreme condition even after natural disaster as well as serving as food for predators in order to maintain balance of nature. So, dormancy can be inhibited by some phytochemical components like terpenoids, polyphenoliic compounds, flavonoids, alkaloids and glycosides by the mechanism of inhibiting water uptake system III and II, surface sterilization, reverse mobilization, cell elongation etc
Researches Regarding the Influence of Certain Natural Herbicides on Seed Germination
2011
The signaling and identification of phytotoxic substances in soil is a very difficult problem. The main cause of this difficulty is that many of these phytotoxic substances, especially the organic ones, are ephemeral, transform rapidly and this changes the character of their physiological action on plants. As germination is the main characteristic of sowing seeds, the phytotoxicity of extracts on the plant growth and development can be followed through the effects they produce on seed germination. A characteristic that can be followed is the way the radical system develops. The radicals in particular are especially sensitive to the action exerted by the phytotoxic substances. Thus, the region of the root apical meristem develops abnormally, exteriorizing by their discoloration and then their complete mortification. In most cases, the effect of the phytotoxic extracts on the apical meristem is very quick. The root necrosis is observed an hour after the exposure of the roots to the ph...
Germination Inhibitory (BLACPMA 2014)
www.blacpma.usach.cl Artículo Original | Original Article 351 In memorian Professor Luis Astudillo, Universidad de Talca, Chile Germination inhibitory activity of selected plants from Central South of Chile [Actividad inhibitoria de la germinación de plantas seleccionadas del Centro-Sur de Chile] Abstract: Methanol extract obtained from aerial parts of 24 selected plants from Central Valley and Pre-andean foothill from Ñuble Province of Chile were tested for its inhibitory germination activity against Trifolium repens and Raphanus sativus. Many extracts (13/24 = 54%) showed inhibition of T. repens germination with IG% > 50%, but none on R. sativus.
Changes in the sensitivity of parasitic weed seeds to germination stimulants
Seed Science Research, 2004
The effects of preconditioning temperature and preconditioning period on the sensitivity of parasitic weed seeds to the synthetic germination stimulant GR24 were studied under laboratory and field conditions. The temperature during preconditioning of Orobanche cumana and Striga hermonthica seeds strongly affected the responsiveness of the seeds to the applied germination stimulant. Preconditioning at an optimal temperature (21°C for O. cumana and 30°C for S. hermonthica) rapidly released dormancy and increased the sensitivity to GR24 by several orders of magnitude. After reaching maximum sensitivity, prolonged preconditioning rapidly induced secondary dormancy, i.e. decreased sensitivity of O. cumana and S. hermonthica to GR24. The rapid change in sensitivity of preconditioned seeds to germination stimulants during prolonged preconditioning was particularly visible at low concentrations of GR24. GR24 at higher concentrations (0.1 and 1 mg l -1 ) usually induced high germination of both species, regardless of the preconditioning period. The striking similarities between the response of parasitic weed seeds to GR24, described here, and results in the literature on non-parasitic wild plant seeds are discussed. Our results show that parasitic weed seeds are highly sensitive to the germination stimulant for a short period of time only, and then enter into secondary dormancy relatively quickly. The similar germination pattern of S. hermonthica seeds preconditioned for prolonged periods of time under laboratory and field conditions suggests that the mechanism observed is of ecological significance.
Horse Gram Seed Germination Inhibition Profiles in Response to Antimitotic Compounds
Seed germination inhibition in green gram (Phaseolus radiatus) by compounds inhibitory to cell division has previously formed the basis of an in vitro assay system for the identification of these potential drugs. Presently, we are extending the scope of these studies, using the germinating seeds of another legume, namely horse gram (Macrotyloma uniflorum) as a model system. We report that the horse gram seed germination was maximally inhibited by vinblastine and the cancer palliative herbal drug HST-K drug, derived from Asteracantha longifolia (Patent No.GB2454875 A) as evident from profiles of seed weight and selected hydrolytic enzymes, measured over 24-120h. We propose that the seed germination inhibition assay deserves to be evaluated with different species of seeds for the identification of antimitotic compounds that could serve as potentially efficacious remedies with fewer side effects posed during the treatment of malignant disorders.
SAR Studies of Sesquiterpene Lactones as Orobanche cumana Seed Germination Stimulants
Journal of Agricultural and Food Chemistry, 2002
Studies of the structure-activity relationship (SAR) directed to evaluate the effect of several sesquiterpene lactones (SL) as germination stimulants of three Orobanche spp. (O. cumana, O. crenata, and O. ramosa) have been achieved. Results are compared with those obtained in the same bioassay with an internal standard, the synthetic analogue of strigol GR-24. A high specificity in the germination activity of SL on the sunflower parasite O. cumana has been observed, and a relationship between such activity and the high sunflower SL content is postulated. Molecular properties of the natural and synthetic germination stimulants (GR-24, GR-7, and Nijmegen-1) and SL have been studied using MMX and PM3 calculations. Consequently, comparative studies among all of them and their activities have been made. SL tested present similarities in molecular properties such as the volume of the molecule and the spatial disposition of the carbon backbone to the natural germination stimulant orobanchol. These properties could be related to their biological activity.
Sunflower sesquiterpene lactone models induce Orobanche cumana seed germination
Phytochemistry, 2000
Six sun¯ower sesquiterpene lactone models which share structural features of the lactone rings of strigol and its synthetic analogues, the GR family, with dierent conformational¯exibilities were tested as Orobanche cumana germination stimulants. Among them, parthenolide and 3,5-dihydroxydehydrocostus-lactone signi®cantly increased O. cumana germination, presenting higher activity than GR-24, used as a standard in the germination bioassay. The eect of these two compounds is species-speci®c, showing no germination stimulant activity on other Orobanche spp. tested (O. crenata, O. ramosa and O. aegyptiaca ). Data presented are discussed in terms of a structure-activity relationship. #
Seed germination of agricultural weeds is promoted
Here we report that a synthesised form of a naturally occurring chemical (a butenolide, 3-methyl-2H-furo[2,3-c]pyran-2-one) found in smoke can stimulate seedling emergence of the economically important weed species Avena fatua L. (Poaceae), Arctotheca calendula (L.) Levyns (Asteraceae), Brassica tournefortii Gouan (Brassicaceae), and Raphanus raphanistrum L. (Brassicaceae) under field conditions at rates equivalent to 2-20 g/ha a.i. The butenolide also stimulates germination of freshly collected seeds from wild populations of these species, as well as those of Sisymbrium orientale L. (Brassicaceae), Hordeum leporinum Link (Poaceae) and Echium plantagineum L. (Boraginaceae) under laboratory conditions, consistently greater than that of smoke water. Experiments using B. tournefortii seeds collected from several locations across Western Australia and in different growing seasons found that these factors significantly influence the butenolide response, implying a role of the maternal environment in seed germination/dormancy characteristics. This research highlights the potential of butenolide as an agent for broad acre weed control and land restoration.
Industrial Crops and Products, 2010
Ethanol extracts obtained from aerial parts of 71 native plants from Central Argentina were tested for their herbicidal activity in germination assays on Avena sativa and Raphanus sativus. Extracts derived from Angelphytum aspilioides, Baccharis salicifolia, Cortaderia rudiuscula, Eupatorium hookerianum and Mandevilla laxa, showed 100% inhibition of the germination of A. sativa at 10 mg/ml. In the case of R. sativus, extracts from Achyrocline tomentosa, Angelphytum aspilioides, B. salicifolia, Melissa officinalis, Minthostachys verticillata, Ophryosporus charua and Podranea ricasoliana, applied at 10 mg/ml, showed 100% germination inhibition. For each extract, the mean effective concentrations that inhibit germination (ECg 50 ), root (ECr 50 ) and shoot (ECs 50 ) growth were determined. According to these values and the extract yield, an index was calculated in order to establish a ranking of the most active plants. For inhibition of A. sativa, the ranking was B. salicifolia > A. aspilioides > C. rudiuscula > M. laxa > E. hookerianum. The ECg 50 , ECr 50 and ECs 50 of B. salicifolia against A. sativa were 0.36, 0.88 and 0.91 mg/ml, respectively, showing more activity than that of 2,4-D as a germination inhibitor and 44 and 1.1 times less active than 2,4-D as a root and shoot inhibitor, respectively. The ranking for the inhibition of R. sativus was O. charua > A. aspilioides > P. ricasoliana > B. salicifolia > A. tomentosa > M. officinalis > M. verticillata. The O. charua extract presented ECg 50 , ECr 50 and ECs 50 of 1.04, 1.04 and 1.49 mg/ml, respectively. According to the obtained results, the extracts of B. salicifolia and of A. aspilioides were the only ones capable of inhibiting the germination and growth of both test species.