BEGIN:VCALENDAR VERSION:2.0 X-WR-CALNAME:EventsCalendar PRODID:-//hacksw/handcal//NONSGML v1.0//EN CALSCALE:GREGORIAN BEGIN:VTIMEZONE TZID:America/New_York LAST-MODIFIED:20240422T053451Z TZURL:https://www.tzurl.org/zoneinfo-outlook/America/New_York X-LIC-LOCATION:America/New_York BEGIN:DAYLIGHT TZNAME:EDT TZOFFSETFROM:-0500 TZOFFSETTO:-0400 DTSTART:19700308T020000 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU END:DAYLIGHT BEGIN:STANDARD TZNAME:EST TZOFFSETFROM:-0400 TZOFFSETTO:-0500 DTSTART:19701101T020000 RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU END:STANDARD END:VTIMEZONE BEGIN:VEVENT CATEGORIES:Lectures and Seminars,Thesis/Dissertations DESCRIPTION:Advisor: Dr. Mark Silby Committee members: Dr. Christopher Br igham, Dr. Robert Drew Abstract: Rhizobacteria such as Pseudomonas fluo rescens Pf0-1 are important contributors to plant health due to their invo lvement in nutrient uptake, regulation of plant immunity, and inhibition o f pathogens. P. fluorescens Pf0-1 mediates movement by using microscopic h air-like structures called flagella. Flagella synthesis is controlled by t he bacterial enhancer binding protein (bEBP) FleQ; fleQ mutants are unable to swim. Taylor et al., (2015) showed that fleQ mutants eventually regain motility due to new mutations in ntrB and ntrC which result in elevated a ctivation of NtrC and off-target binding of the bEBP NtrC to FleQ-controll ed promoters. We hypothesized that if mutations that activate bEBPs can le ad to crosstalk between regulatory networks, environmental signals that ac tivate bEBPs may also influence crosstalk in a post-translational manner. We tested whether glutamate or alpha ketoglutarate which are predicted to activate AauR and MifR respectively could restore motility in the Pf0-1 fl eQ mutant and found that the addition of glutamate restored motility. Howe ver, deletion of aauR did not abolish motility restoration, indicating tha t a different bEBP was important. Surprisingly, deletion of ntrC rendered glutamate unable to promote motility restoration, demonstrating that in th e presence of glutamate wildtype NtrC can functionally replace FleQ in P. fluorescens. Measurement of transcription of the gene flhA which is normal ly FleQ-controlled confirmed that in the presence of glutamate, NtrC is ca pable of regulating expression of flagella genes. This research looks to p rovide an insight on how crosstalk between different regulatory pathways c an increase the adaptability of bacteria in complex natural environments. \nEvent page: https://www.umassd.edu/events/cms/biology-ms-thesis- defense-by-sharon-jacob-.php X-ALT-DESC;FMTTYPE=text/html:

Advisor: Dr. Mark Silby

Committee members: Dr. Christopher Brigham\, Dr. Robert Drew

Abstract: Rhizobacteria such as Pseudomonas fluorescens Pf0-1 are importa nt contributors to plant health due to their involvement in nutrient uptak e\, regulation of plant immunity\, and inhibition of pathogens. P. fluores cens Pf0-1 mediates movement by using microscopic hair-like structures cal led flagella. Flagella synthesis is controlled by the bacterial enhancer b inding protein (bEBP) FleQ\; fleQ mutants are unable to swim. Taylor et al .\, (2015) showed that fleQ mutants eventually regain motility due to new mutations in ntrB and ntrC which result in elevated activation of NtrC and off-target binding of the bEBP NtrC to FleQ-controlled promoters. We hypo thesized that if mutations that activate bEBPs can lead to crosstalk betwe en regulatory networks\, environmental signals that activate bEBPs may als o influence crosstalk in a post-translational manner. We tested whether gl utamate or alpha ketoglutarate which are predicted to activate AauR and Mi fR respectively could restore motility in the Pf0-1 fleQ mutant and found that the addition of glutamate restored motility. However\, deletion of aa uR did not abolish motility restoration\, indicating that a different bEBP was important. Surprisingly\, deletion of ntrC rendered glutamate unable to promote motility restoration\, demonstrating that in the presence of gl utamate wildtype NtrC can functionally replace FleQ in P. fluorescens. Mea surement of transcription of the gene flhA which is normally FleQ-controll ed confirmed that in the presence of glutamate\, NtrC is capable of regula ting expression of flagella genes. This research looks to provide an insig ht on how crosstalk between different regulatory pathways can increase the adaptability of bacteria in complex natural environments.

E vent page: https://www.umassd.edu/events/cms/biology-ms-t hesis-defense-by-sharon-jacob-.php

DTSTAMP:20260421T150720 DTSTART;TZID=America/New_York:20260513T120000 DTEND;TZID=America/New_York:20260513T130000 LOCATION:SENG 118 SUMMARY;LANGUAGE=en-us:Biology MS Thesis Defense by Sharon Jacob UID:89abd04b5389b84d3f7ff6488bf1b128@www.umassd.edu END:VEVENT END:VCALENDAR