Photodegradation of Myrigalone A, an Allelochemical from Myrica gale: Photoproducts and Effect of Terpenes

2019 ◽  
Vol 67 (26) ◽  
pp. 7258-7265 ◽  
Author(s):  
Amina Khaled ◽  
Mohamad Sleiman ◽  
Etienne Darras ◽  
Aurélien Trivella ◽  
Cédric Bertrand ◽  
...  
Keyword(s):  
Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
J Fang ◽  
C Paetz ◽  
B Schneider

2014 ◽  
Vol 8 (1) ◽  
pp. 9-17
Author(s):  
X. Chang ◽  
P. Martin

To investigate whether the fertilizers N, P or K individually affect plant growth, oil content and the gender of sweet gale, two trials, pot and field trials, were carried out at Orkney College UHI in Scotland. A pot trial was established with eight soils which were collected from different sweet gale trial sites in the north of Scotland. Although neither shoot yield nor oil concentration in shoots was affected by soil, there were significant differences in shoot yields as a result of fertilizer treatments (nitrogen (N), phosphorus (P), potassium (K) or none (control)). The best yield was obtained from the N treatment which was double to that of the control and P treatments. N, P or K fertilizers did not consistently affect shoot oil concentration in two seasons; however, oil yield was significantly affected, and N treatment produced two-three fold oil yield increases compared with the control or P treatment. In the N treatment, the increase in shoot yield was positively correlated with total nitrogen or nitrate nitrogen in the soil, suggesting the occurrence of a nitrogen priming effect. Data suggested that as shoot yield increased the oil concentration in shoots decreased. Neither soil nor N, P or K fertilizers had a significant effect on oil composition. Amongst fertilizer treatments, P resulted in the largest number of plants changing gender from female to male. A field N trial confirmed that nitrogen significantly enhanced the shoot yield of young plants.


1976 ◽  
Vol 194 (1116) ◽  
pp. 285-293 ◽  

In cross-inoculation trials, inocula containing the nodule endophytes of Myrica gale, M. cerifera, M. cordifolia and M. pilulifera respectively were applied to the roots of young plants of M. faya Ait. growing in nitrogen-free culture solution. All four inocula induced nodule formation, and except where the M. gale inoculum had been used the nodules were of effective type and enabled the plants bearing them to grow nearly as well as other M. faya plants associated with the normal endophyte. The nodules induced by the M. gale endophyte were very numerous, but remained small and fixed no significant amount of nitrogen, and were thus ineffective. Light and electron microscopy showed that in the effective nodules induced by the normal endophyte or by that of M. cordifolia , the endophyte was confined to a layer 1-2 cells deep near the middle of the nodule cortex, and that in respect of the width of the hyphae and their production of club-shaped internally subdivided vesicles, the endophytes resembled closely those in the nodules of the few other species of Myrica that have been studied by modern methods of microscopy. In ineffective nodules the disposition of the infected cells was unchanged, but within the cells only a sparse development of the endophyte was observed, and no vesicles were found. The finding that nodules lacking vesicles showed little or no fixation is consistent with other evidence that the vesicles normally produced by non-legume nodule endophytes are the main site of nitrogen fixation.


1983 ◽  
Vol 61 (11) ◽  
pp. 2937-2942 ◽  
Author(s):  
Christa R. Schwintzer ◽  
John D. Tjepkema

Annual CO2 evolution, H2 evolution, and C2H2 reduction were measured in root nodules from a vigorous Myrica gale stand in a Massachusetts peatland at 3-week intervals in 1980. Nodule activity was approximately the same under the experimental conditions (excised nodules reducing C2H2) as in nature (attached nodules reducing N2) and the CO2 evolution to O2 uptake ratio averaged 1.07. Nitrogenase activity was first detectable in late May, reached its maximum [Formula: see text] in mid-July, and disappeared in late October. The seasonal pattern of CO2 evolution was similar except that it continued at low rates when nitrogenase activity was absent. Hydrogen evolution was barely detectable. The energy cost of nitrogen fixation, expressed as the molar CO2:C2H4 ratio, was relatively low [Formula: see text] throughout the period of substantial nitrogenase activity and had a mean annual value of 4.9. Annual N2 fixation was estimated to be 2.8 g N m−2year−1, contributing about 33% of the annual N requirement measured in 1979. Annual C use by nodules was about 21.0 g C m−2 year−1. If this C were available for additional net production, it would increase it by about 5.5%.


2001 ◽  
Vol 79 (3) ◽  
pp. 341-361 ◽  
Author(s):  
Stefan Hotes ◽  
Peter Poschlod ◽  
Hiroshige Sakai ◽  
Takashi Inoue

Mires in coastal lowlands in Hokkaido, northern Japan, have repeatedly been affected by flooding events and tephra (aerially transported volcanic ejecta) deposition during their development. Vegetation, hydrology, and stratigraphy of Kiritappu Mire in eastern Hokkaido were investigated along two transects and are discussed in relation to disturbance by mineral deposition. The vegetation pattern showed little relation to past geologic events. Five plant communities, two of which (A and C) could be further divided into subgroups, were distinguished (A, Alnus japonica - Spiraea salicifolia community; B, Sasa chartacea community; C, Myrica gale var. tomentosa - Sphagnum fuscum community; D, Carex lyngbyei community; E, Carex subspathacea - Aster tripolium community). Water levels, pH, electric conductivity, and ionic composition of groundwater and surface water were measured in communities A-C. Mean water levels were similar in communities A and C; in community B, it was lower. The pH was higher in community A than in communities B and C. Ion concentrations were influenced by sea water at some sites. Plant macrofossils and ash contents of 31 cores were analysed. Sedge roots were the dominant peat component, often mixed with remains of Phragmites australis, Sphagnum spp., and Polytrichum juniperinum var. strictum. Ash contents were high, and up to nine different mineral layers consisting of tephra, sand, silt, and clay were detected. In some cases, mineral deposition induced changes in the macrofossil composition of the peat. However, in a greater number of cases, no changes in the macrofossil composition were found at the mineral layers, and most shifts were not related to mineral deposition.Key words: mire, vegetation, hydrology, disturbance, flooding, tephra.


1997 ◽  
Vol 75 (9) ◽  
pp. 1415-1423 ◽  
Author(s):  
Christa R. Schwintzer ◽  
John D. Tjepkema

The time course of acetylene reduction was examined in field nodules of speckled alder (Alnus incana ssp. rugosa (Du Roi) Claus.) and sweet gale (Myrica gale L.) with an open flow-through system. When detached speckled alder nodules were measured in the laboratory, there was an initial peak rate of nitrogenase activity between 2 and 3 min followed by pronounced declines to 50% of the peak rate (early summer) and 66% (late summer) at 9 min, after which there was little further change. Speckled alder nodules measured in the field while still attached to the plant also had a peak rate between 2 and 3 min. Most sweet gale nodules had a peak rate at 2–3 min and a sharp decline to 27% at 21 min followed by a partial recovery to 49% at 60 min. The time courses of field nodules of speckled alder and sweet gale were comparable with those of intact, growth chamber grown seedlings. The initial peak rate is the most accurate measure of nitrogenase activity and the only reliable way to measure this is with an open, flow-through system. We describe a simple, inexpensive, flow-through system for use in the field. Key words: acetylene-induced decline, Alnus incana ssp. rugosa, actinorhizal plants, Myrica gale, nitrogen fixation, nitrogenase activity.


1999 ◽  
Vol 65 (10) ◽  
pp. 4521-4527 ◽  
Author(s):  
Michael L. Clawson ◽  
David R. Benson

ABSTRACT Actinorhizal plants invade nitrogen-poor soils because of their ability to form root nodule symbioses with N2-fixing actinomycetes known as Frankia. Frankia strains are difficult to isolate, so the diversity of strains inhabiting nodules in nature is not known. To address this problem, we have used the variability in bacterial 16S rRNA gene sequences amplified from root nodules as a means to estimate molecular diversity. Nodules were collected from 96 sites primarily in northeastern North America; each site contained one of three species of the family Myricaceae. Plants in this family are considered to be promiscuous hosts because several species are effectively nodulated by most isolated strains ofFrankia in the greenhouse. We found that strain evenness varies greatly between the plant species so that estimating total strain richness of Frankia within myricaceous nodules with the sample size used was problematical. Nevertheless, Myrica pensylvanica, the common bayberry, was found to have sufficient diversity to serve as a reservoir host for Frankia strains that infect plants from other actinorhizal families. Myrica gale, sweet gale, yielded a few dominant sequences, indicating either symbiont specialization or niche selection of particular ecotypes. Strains in Comptonia peregrina nodules had an intermediate level of diversity and were all from a single major group of Frankia.


Nature ◽  
1949 ◽  
Vol 163 (4149) ◽  
pp. 730-730 ◽  
Author(s):  
G. BOND
Keyword(s):  

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