Belowground interactions between Kalmia angustifolia and Picea mariana: roles of competition, root exudates and ectomycorrhizal association

2016 ◽  
Vol 403 (1-2) ◽  
pp. 471-483 ◽  
Author(s):  
Azim U. Mallik ◽  
Shekhar R. Biswas ◽  
Laura C. Siegwart Collier
Keyword(s):  
Root Exudates ◽  
Picea Mariana ◽  
Kalmia Angustifolia ◽  
Belowground Interactions ◽  
Ectomycorrhizal Association

Mechanisms of interaction between Kalmia angustifolia cover and Picea mariana seedlings

2002 ◽  
Vol 32 (11) ◽  
pp. 2022-2031 ◽  
Author(s):  
Anna Wallstedt ◽  
Andrew Coughlan ◽  
Alison D Munson ◽  
Marie-Charlotte Nilsson ◽  
Hank A Margolis
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Water Soluble ◽  
Organic Layer ◽  
Belowground Competition ◽  
Soil Microbial ◽  
Kalmia Angustifolia ◽  
Seedling Biomass ◽  
Soluble Phenols ◽  
Different Levels

Sites dominated by Kalmia angustifolia L. are often associated with slow decomposition of organic matter, decreased nitrogen (N) mineralization rates, and low black spruce (Picea mariana (Mill.) BSP) productivity. The objective of this study was to separate the effects of belowground competition by Kalmia from the effects of water-soluble soil phenols on black spruce seedlings growing under different levels of Kalmia cover. A factorial greenhouse bioassay was established in which black spruce seedlings were grown for 6 months in intact blocks of soil with three different levels of Kalmia cover. The soil was treated with charcoal to reduce the amounts of water-soluble phenols, and (or) tubes were inserted to exclude Kalmia roots. At low Kalmia cover, reducing the level of belowground competition increased seedling biomass by 134%. However, reducing belowground competition did not increase seedling biomass at the two higher levels of Kalmia cover. It is possible that seedling biomass remained low because of an increased immobilization of N in the organic layer. Furthermore, the proportion of ectomycorrhiza morphotypes differed among seedlings growing under different levels of Kalmia cover. The effect of water-soluble phenols on seedling growth remains uncertain, since we observed a confounding effect of the charcoal treatment on soil microbial biomass and seedling response.

Cree antidiabetic plant extracts display mechanism-based inactivation of CYP3A4

2011 ◽  
Vol 89 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Teresa W. Tam ◽  
Rui Liu ◽  
John T. Arnason ◽  
Anthony Krantis ◽  
William A. Staines ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Cytochrome P450 3A4 ◽  
Cyp3a4 Inhibition ◽  
Kalmia Angustifolia ◽  
Lycopodium Clavatum ◽  
Rhododendron Tomentosum

Seventeen Cree antidiabetic medicinal plants were studied to determine their potential to inhibit cytochrome P450 3A4 (CYP3A4) through mechanism-based inactivation (MBI). The ethanolic extracts of the medicinal plants were studied for their inhibition of CYP3A4 using the substrates testosterone and dibenzylfluorescein (DBF) in high pressure liquid chromatography (HPLC) and microtiter fluorometric assays, respectively. Using testosterone as a substrate, extracts of Alnus incana , Sarracenia purpurea , and Lycopodium clavatum were identified as potent CYP3A4 MBIs, while those from Abies balsamea , Picea mariana , Pinus banksiana , Rhododendron tomentosum , Kalmia angustifolia , and Picea glauca were identified as less potent inactivators. Not unexpectedly, the other substrate, DBF, showed a different profile of inhibition. Only A. balsamea was identified as a CYP3A4 MBI using DBF. Abies balsamea displayed both NADPH- and time-dependence of CYP3A4 inhibition using both substrates. Overall, several of the medicinal plants may markedly deplete CYP3A4 through MBI and, consequently, decrease the metabolism of CYP3A4 substrates including numerous medications used by diabetics.

scholarly journals Growth release of stunted black spruce (Picea mariana) in Kalmia heath: the role of ectomycorrhizal fungi and near-ground microclimate

2016 ◽  
Vol 46 (5) ◽  
pp. 666-673 ◽  
Author(s):  
Philippe St. Martin ◽  
Azim U. Mallik
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Chemical Properties ◽  
Root Tips ◽  
Eastern Canada ◽  
Stunted Growth ◽  
Growth Release ◽  
Kalmia Angustifolia ◽  
Significant Difference ◽  
Ecm Fungi

Naturally regenerating and planted black spruce (Picea mariana (Mill.) B.S.P.) in post-fire landscapes in eastern Canada often exhibit stunted growth in the presence of ericaceous shrubs such as Kalmia angustifolia L. After a period of stunted growth, some seedlings experience a growth release, exhibiting growth rates closer to normally growing seedlings. We hypothesized that an increase in colonization of root tips by ectomycorrhizal (ECM) fungi is responsible for this release and that the percentage of root tips colonized by ECM fungi would be higher on seedlings that had a released or normally growing neighbour within close proximity. We quantified ECM fungi diversity and abundance from 255 soil cores from stunted, released, and normally growing black spruce seedlings sampled in two Kalmia-dominated sites in Newfoundland. Growth and microsite characteristics around each seedling were also measured. We found that normal and released seedlings had significantly higher proportions of ECM fungi root tips than stunted seedlings, supporting our final hypothesis; however, there was no significant difference in distance between neighbours. Soil chemical properties are thought to inhibit the vegetative spread of ECM fungi species in this particular system and are identified as an important topic for further research.

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