Analysis of the Interactions Between the Septate Fungus Darksidea sp. and Artemisia tridentata Roots
Faculty Mentor Information
Marcelo Serpe
Abstract
Artemisia tridentata (big sagebrush) roots form symbioses with various fungi including dark septate endophytes (DSE). In previous work, a DSE was isolated from sagebrush roots and identified within the genus Darksidea in the Pleosporales. To analyze the association between Darksidea sp. and sagebrush, we conducted a factorial combination experiment consisting of two inoculation treatments (non-inoculated and inoculated seedlings) and two soil treatments (sterilized and non-sterilized soil). Three months after inoculation, colonization by septate fungi in the sterilized soil was 10 and 57% (p < 0.0001) for non-inoculated and inoculated seedlings, respectively, whereas colonization in the non-sterilized soil was 39 and 61% (p = 0.04) for non-inoculated and inoculated seedlings, respectively. To ascertain that the increases in colonization were at least in part attributed to the presence of Darksidea sp., we extracted DNA from the roots and conducted PCRs with primers specific to the Darksidea genus. Amplification occurred with most DNA samples from inoculated seedlings, but none of the samples from non-inoculated ones. In addition, microscopic analysis revealed that Darksidea sp colonized all root tissues. Notwithstanding the high levels of colonization, Darksidea did not have any apparent negative effect on the seedlings, suggesting that the symbiosis is not parasitic.
Analysis of the Interactions Between the Septate Fungus Darksidea sp. and Artemisia tridentata Roots
Artemisia tridentata (big sagebrush) roots form symbioses with various fungi including dark septate endophytes (DSE). In previous work, a DSE was isolated from sagebrush roots and identified within the genus Darksidea in the Pleosporales. To analyze the association between Darksidea sp. and sagebrush, we conducted a factorial combination experiment consisting of two inoculation treatments (non-inoculated and inoculated seedlings) and two soil treatments (sterilized and non-sterilized soil). Three months after inoculation, colonization by septate fungi in the sterilized soil was 10 and 57% (p < 0.0001) for non-inoculated and inoculated seedlings, respectively, whereas colonization in the non-sterilized soil was 39 and 61% (p = 0.04) for non-inoculated and inoculated seedlings, respectively. To ascertain that the increases in colonization were at least in part attributed to the presence of Darksidea sp., we extracted DNA from the roots and conducted PCRs with primers specific to the Darksidea genus. Amplification occurred with most DNA samples from inoculated seedlings, but none of the samples from non-inoculated ones. In addition, microscopic analysis revealed that Darksidea sp colonized all root tissues. Notwithstanding the high levels of colonization, Darksidea did not have any apparent negative effect on the seedlings, suggesting that the symbiosis is not parasitic.