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Full-Text Articles in Biology

Deep Learning Can Be Used To Classify And Segment Plant Cell Types In Xylem Tissue, Reem Al Dabagh, Benjamin Shin, Sean Wu, Fabien Scalzo, Helen Holmlund, Jessica Lee, Chris Ghim, Samuel Fitzgerald, Marinna Grijalva Mar 2024

Deep Learning Can Be Used To Classify And Segment Plant Cell Types In Xylem Tissue, Reem Al Dabagh, Benjamin Shin, Sean Wu, Fabien Scalzo, Helen Holmlund, Jessica Lee, Chris Ghim, Samuel Fitzgerald, Marinna Grijalva

Seaver College Research And Scholarly Achievement Symposium

Studies of plant anatomical traits are essential for understanding plant physiological adaptations to stressful environments. For example, shrubs in the chaparral ecosystem of southern California have adapted various xylem anatomical traits that help them survive drought and freezing. Previous studies have shown that xylem conduits with a narrow diameter allows certain chaparral shrub species to survive temperatures as low as -12 C. Other studies have shown that increased cell wall thickness of fibers surrounding xylem vessels improves resistance to water stress-induced embolism formation. Historically, these studies on xylem anatomical traits have relied on hand measurements of cells in light micrographs, …


Investigation Of Antimicrobial Properties Of Rhus Ovata Extracts, Sydney T. Adams Mar 2018

Investigation Of Antimicrobial Properties Of Rhus Ovata Extracts, Sydney T. Adams

Seaver College Research And Scholarly Achievement Symposium

Native peoples of Southern California historically used a variety of local plants as remedies for illnesses. Chaparral species such as Rhus ovata (sugar bush) were widely available and were used to ease headaches, coughs and chest pains, and colds. In light of the historical importance of this plant and other chaparral species, recent fungal pathogen-induced diebacks of Malosma laurina, a species closely related to R. ovata, have raised questions regarding the innate defenses of these plants against fungal pathogens. We attempted to scientifically evaluate the traditional medicinal use of R. ovata and its antifungal resistance by testing two …


Potential Spread Of The Fungal Pathogen Botryospharea Dothidea From Chaparral Shrubs To Grape Vineyards In The Santa Monica Mountains, Alexandra N. Case, Natalie M. Aguirre, Rodney L. Honeycutt, Stephen D. Davis Mar 2018

Potential Spread Of The Fungal Pathogen Botryospharea Dothidea From Chaparral Shrubs To Grape Vineyards In The Santa Monica Mountains, Alexandra N. Case, Natalie M. Aguirre, Rodney L. Honeycutt, Stephen D. Davis

Seaver College Research And Scholarly Achievement Symposium

We tested the hypothesis that an opportunistic endophytic fungus, Botryosphaeria dothidea, that frequently infects and causes dieback in species of chaparral shrubs in the Santa Monica Mountains during drought events, may spread to grape vineyards in the Santa Monica Mountains. Recently a dominant chaparral species in coastal exposures of the Santa Monica Mountains, Malosma laurina, has undergone extensive dieback in low elevation, dry sites, in response to historic drought in California, but less dieback in high elevation moist sites. M. laurina frequently grows adjacent grape vineyards. Thus we hypothesized that fungal isolates from a low elevation, dry vineyard …


Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis Mar 2017

Hydraulic Mechanisms Of Fungal-Induced Dieback In A Keystone Chaparral Species During Unprecedented Drought In California, Natalie M. Aguirre, Marissa E. Ochoa, Helen I. Holmlund, Frank E. Ewers, Stephen D. Davis

Seaver College Research And Scholarly Achievement Symposium

Between 2012-2016, southern California experienced unprecedented drought that caused dieback in Malosma laurina, a keystone species of chaparral shrub communities. Dieback was especially severe in coastal exposures of the Santa Monica Mountains, leading to whole plant mortality exceeding 50% at some sites. We hypothesized that the endophytic fungus causing the dieback, Botryosphaeria dothidea, was successful in invading the xylem tissue of M. laurina because of protracted water stress, carbon starvation, or a combination of the two. We tested these possibilities in a controlled pot experiment by comparing three treatments, each inoculated with the fungus: (1) irrigated controls (2) …


Root Hydraulic Conductance In Malosma Laurina Experiencing Severe Dieback In The Santa Monica Mountains, Natalie M. Aguirre 5861995, Avery Davis, Sarah Nelson Apr 2016

Root Hydraulic Conductance In Malosma Laurina Experiencing Severe Dieback In The Santa Monica Mountains, Natalie M. Aguirre 5861995, Avery Davis, Sarah Nelson

Seaver College Research And Scholarly Achievement Symposium

Malosma laurina is a dominant species in coastal chaparral ecosystems The deep root systems of M. laurina provide structural support for the steep Santa Monica Mountains and allow M. laurina to tap into the deep water table. M. laurina dieback is prevalent in coastal exposures of the SMM, presumably due to historic drought predisposing plant tissues to infection by the fungal pathogen Botryosphaeria dothidea. In ecosystems that experience annual dry periods, a high hydraulic conductance in roots is necessary to provide plants with sufficient water. A recent study has examined the effect of Botryosphaeria on the hydraulic conductance of M. …


Extracts Of Trichostema Lanatum Inhibit The Growth Of Gram-Positive Bacteria And An Escherichia Coli Δtolc Mutant Strain, Matthew C. Fleming Mar 2014

Extracts Of Trichostema Lanatum Inhibit The Growth Of Gram-Positive Bacteria And An Escherichia Coli Δtolc Mutant Strain, Matthew C. Fleming

Seaver College Research And Scholarly Achievement Symposium

The Chumash Native Americans of Southern California have well-documented traditions of using plants for medicinal purposes. If a specific plant has traditionally been used for the treatment of cuts, wounds and infections, it may contain chemicals with anti-bacterial properties. One plant that fits these criteria is Trichostema lanatum (woolly blue curls). We tested extracts of T. lanatum for their ability to inhibit the growth of a variety of bacteria. Because of the widespread use of antibiotics over the past sixty years bacteria are evolving greater resistance to known antibiotics, but unfortunately the rate of antibiotic discovery has diminished during the …