Arbuscular Mycorrhizal Fungi in a Changing Global Environment
Angelard, C., Tanner, C.J., Fontanillas, P., Niculita-Hirzel, H., Masclaux, F. and Sanders, I.R. 2014. Rapid genotypic change and plasticity in arbuscular mycorrhizal fungi is caused by a host shift and enhanced by segregation. The International Society for Microbial Ecology Journal 8: 284-294.
Hypothesizing that (1) "AMF respond rapidly to a change of environment (plant host) through changes in the frequency of nucleotypes," that (2) "genotypically novel offspring exhibit different genetic responses to environmental change than the parent," and that (3) "genotypically novel offspring exhibit a wide range of phenotypic plasticity to a change of environment," Angelard et al. "subjected AMF parents and offspring to a host shift," working with hyphae and spores produced vegetatively from AMF lines growing on Daucus carota (carrot) and Solanum tuberosum (potato). In doing so the six scientists report "quantitative molecular analyses showed that a host shift induced a significant alteration in relative allele frequencies among initial and segregated AMF lines," and they say "this result shows that alleles were likely to be located on different nuclei inside the fungus and that the different nuclei had changed frequency in response to the host shift."
Angelard et al. say their results demonstrate (1) "AMF can rapidly undergo genotypic change in response to the environment they experience," (2) "changes in nucleotype frequency can have a role in performance in a new environment," (3) "the ability to rapidly change genotype composition is important as it provides a mechanism for the fungus to be plastic when growing from plant to plant," and (4) "the ability to alter nucleotype frequencies offers a greater potential for adaptability to the different environments the fungus experiences than that which could occur by plasticity in one genome," all of which suggests that plants associated with AMF may be much more capable of adjusting to changing environments than has long been believed possible.
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