Vesicular-arbuscular mycorrhizal fungi can affect the water balance of both amply watered and droughted host plants. This review summarizes these effects and possible causal mechanisms. Also discussed are host drought resistance and the influence of soil drying on the fungi.

Water relations, drought and vesicular-arbuscular mycorrhizal symbiosis

Biology, immunology, and cariogenicity of Streptococcus mutans

https://www.fs.fed.us/rm/pubs_other/rmrs_1999_neary_d001.pdf

Fire effects on belowground sustainability: a review and synthesis

Advances in copper complexes as anticancer agents.

Summary • Numerous field studies have measured mycorrhizal dynamics under additions of nitrogen (N), phosphorus (P), or atmospheric CO 2 to test the hypothesis that plants should invest in mycorrhizal fungi when soil nutrients are limiting. • Here meta-analyses were used to integrate nutrient responses across independent field-based studies. Responses were compared between ecto- and arbuscular mycorrhizal fungi, and among fertilizer types, methods of measurement, biomes, and lead investigators. Relationships between degree of response and study length, fertilization rates, total amounts of nutrients applied, and numbers of replicates were also tested. • Across studies, mycorrhizal abundance decreased 15% under N fertilization and 32% under P fertilization. Elevated CO 2 elicited a 47% increase. Nitrogen effects varied significantly among studies, and P effects varied significantly among lead investigators. Most other factors did not affect mycorrhizal responses. • These results support the plant investment hypothesis, and suggest that global standing stocks of mycorrhizal fungi may increase substantially under elevated CO 2 but decline moderately under P additions. Effects of N deposition may be difficult to predict for individual ecosystems, with a slightly negative influence overall.

/pdf/a-meta-analysis-of-mycorrhizal-responses-to-nitrogen-510ilwlfir.pdf

A meta‐analysis of mycorrhizal responses to nitrogen, phosphorus, and atmospheric CO2 in field studies

Thiosemicarbazone complexes of copper(II): structural and biological studies

More than 75 substituted thiosemicarbazones and a number of metal complexes of each have been assayed for their antifungal activity. Their activity is significantly affected by the substituted groups attached at both1
N and4
N of the thiosemicarbazone moiety. Greatest activity occurs for 2-substituted pyridine thiosemicarbazones with differences observed for 2-formylpyridine, 2-acetylpyridine and 2-benzoylpyridine derivatives and their metal complexes. Further, there are activity differences for4
N-alkyl-,4
N-aryl-,4
N-dialkyl- and 3-azacyclothiosemicarbazones and their metal complexes as well as changes in the substituent size among each of these subgroups. Cu(II) complexes are often more active than the uncomplexed thiosemicarbazones, with the latter showing similar activity to Ni(II) complexes in many instances. The reduction potential of the thiosemicarbazone ligand in a Cu(II) complex, the strength of the ligand field and various spectral properties can be correlated to the inhibitory activity.

Antifungal and antitumor activity of heterocyclic thiosemicarbazones and their metal complexes: current status.

Abundance and distribution of vascular plants and vesicular-arbuscular mycorrhizal (VAM) fungi across a soil moisture-nutrient gradient were studied at a single site. Vegetation on the site varied from a dry mesic paririe dominated by little bluestem (Schizachyrium scoparium) to emergent aquatic vegetation dominated by cattail (Typha latifolia) and water smartweed (Polygonum hydropiperoides). Plant cover, VAM spore abundance, plant species richness, and number of VAM fungi represented as spores, had significant positive correlations with each other and with percent organic matter. The plant and VAM spore variables had significant negative correlations with soil pH and available Ca, Mg, P and gravimetric soil moisture. Using stepwise multiple regression, Ca was found to be the best predictor of spore abundance. Test for association between plant species and VAM fungal spores indicated that the spores of Glomus caledonium are associated with plants from dry, nutrient poor sites and spores of gigaspora gigantea are positively associated with plants occurring on the wet, relatively nutrient rich sites. Glomus fasciculatum was the most abundant and widely distributed VAM fungus and it had more positive associations with endophyte hosts than the other VAM fungi. We found no relationship between beta niche breadth of plant species and the presence or absence of mycorrhizal infection. However, our data suggest that some plant species may vary with respect to their infection status depending upon soil moisture conditions that may fluctuate seasonally or annually to favor or hinder VAM associations.

Anthony E. Liberta

Papers

Thiosemicarbazone complexes of copper(II): structural and biological studies

Antifungal and antitumor activity of heterocyclic thiosemicarbazones and their metal complexes: current status.

Interaction of vascular plants and vesicular-arbuscular mycorrhizal fungi across a soil moisture-nutrient gradient.

Copper(II) complexes of 2-benzoylpyridine 4N-substituted thiosemicarbazones

Structures of nickel(II) and copper(II) complexes of 2-acetylpyridine azacyclothiosemicarbazones