Identification of Soil Microbes affecting Early Rhizoid Development of Two Fern Gametophyte Species from the Santa Monica Mountains

Presentation Type

Poster

Presentation Type

Submission

Keywords

Microbes

Department

Biology

Major

Biology B.S.

Abstract

The field of environmental microbiology has begun to unpack the significance of the soil microbiome on the overall health of ecological systems. Interactions between roots of fern sporophytes and soil bacteria are well studied, but less characterized are the potential relationships between soil microbes and free living gametophytes. This study compares the effects of microbes collected from different locations in the Santa Monica Mountains (SMM) on early rhizoid development in gametophytes of two SMM fern species Dryopteris arguta (Da), found in the chaparral understory, and Woodwardia fimbriata (Wf), found in riparian streams. Soil samples were collected from the base of Wf and Da. Spores from both Wf and Da were germinated on agar slides inoculated with water extracts containing soil microbes from each soil sample. Over 20 days, fixed images were collected followed by computational image analysis to quantitatively compare rhizoid development of the two gametophyte species under the various microbial conditions. Limited difference was observed in the average number of rhizoids per gametophyte for Wf under all microbial conditions, while Da had limited significant difference between the Wf soil agar and the other media. However, for both W. fimbriata and D. arguta, the average length of rhizoids is statistically longer in the presence of microbes from both Wf and Da soil in comparison to the sterile agar control. 16s targeted amplicon sequencing on bacterial DNA was used to identify relative abundance of bacterial species in each of the soil samples in order to identify candidates for this differential effect.

Faculty Mentor

Dr. Donna Nofziger

Funding Source or Research Program

Academic Year Undergraduate Research Initiative

Location

Waves Cafeteria

Start Date

24-3-2023 2:00 PM

End Date

24-3-2023 4:00 PM

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Mar 24th, 2:00 PM Mar 24th, 4:00 PM

Identification of Soil Microbes affecting Early Rhizoid Development of Two Fern Gametophyte Species from the Santa Monica Mountains

Waves Cafeteria

The field of environmental microbiology has begun to unpack the significance of the soil microbiome on the overall health of ecological systems. Interactions between roots of fern sporophytes and soil bacteria are well studied, but less characterized are the potential relationships between soil microbes and free living gametophytes. This study compares the effects of microbes collected from different locations in the Santa Monica Mountains (SMM) on early rhizoid development in gametophytes of two SMM fern species Dryopteris arguta (Da), found in the chaparral understory, and Woodwardia fimbriata (Wf), found in riparian streams. Soil samples were collected from the base of Wf and Da. Spores from both Wf and Da were germinated on agar slides inoculated with water extracts containing soil microbes from each soil sample. Over 20 days, fixed images were collected followed by computational image analysis to quantitatively compare rhizoid development of the two gametophyte species under the various microbial conditions. Limited difference was observed in the average number of rhizoids per gametophyte for Wf under all microbial conditions, while Da had limited significant difference between the Wf soil agar and the other media. However, for both W. fimbriata and D. arguta, the average length of rhizoids is statistically longer in the presence of microbes from both Wf and Da soil in comparison to the sterile agar control. 16s targeted amplicon sequencing on bacterial DNA was used to identify relative abundance of bacterial species in each of the soil samples in order to identify candidates for this differential effect.