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:College of Arts and Sciences,Lectures and Seminars,Thesis/Disser tations DESCRIPTION:Advisor: Dr. Mark Silby Committee: Dr. Christopher Brigham, Dr. Robert Drew Abstract: Rhizobacteria such as Pseudomonas fluorescens Pf0- 1 are important contributors to plant health due to their involvement in n utrient uptake, regulation of plant immunity, and inhibition of pathogens. P. fluorescens Pf0-1 mediates movement by using microscopic hair-like str uctures called flagella. Flagella synthesis is controlled by the bacterial enhancer binding protein (bEBP) FleQ; fleQ mutants are unable to swim. Ta ylor et al., (2015) showed that fleQ mutants eventually regain motility du e 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 hypothesized that if mutations that activate bEBPs can lead to crosst alk between regulatory networks, environmental signals that activate bEBPs may also influence crosstalk in a post-translational manner. We tested wh ether glutamate or alpha ketoglutarate which are predicted to activate Aau R and MifR respectively could restore motility in the Pf0-1 fleQ mutant an d found that the addition of glutamate restored motility. However, deletio n of aauR did not abolish motility restoration, indicating that a differen t bEBP was important. Surprisingly, deletion of ntrC rendered glutamate un able to promote motility restoration, demonstrating that in the presence o f glutamate wildtype NtrC can functionally replace FleQ in P. fluorescens. Measurement of transcription of the gene flhA which is normally FleQ-cont rolled confirmed that in the presence of glutamate, NtrC is capable of reg ulating expression of flagella genes. This research looks to provide an in sight on how crosstalk between different regulatory pathways can increase the adaptability of bacteria in complex natural environments.\nEvent page: https://www.umassd.edu/events/cms/biology-master-thesis-defense-by-sharon -jacob.php X-ALT-DESC;FMTTYPE=text/html:

Advisor: Dr. Mark Silby

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

Abstract: R hizobacteria such as Pseudomonas fluorescens Pf0-1 are important contribut ors to plant health due to their involvement in nutrient uptake\, regulati on of plant immunity\, and inhibition of pathogens. P. fluorescens Pf0-1 m ediates movement by using microscopic hair-like structures called flagella . Flagella synthesis is controlled by the bacterial enhancer binding prote in (bEBP) FleQ\; fleQ mutants are unable to swim. Taylor et al.\, (2015) s howed 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 hypothesized tha t if mutations that activate bEBPs can lead to crosstalk between regulator y networks\, environmental signals that activate bEBPs may also influence crosstalk in a post-translational manner. We tested whether glutamate or a lpha ketoglutarate which are predicted to activate AauR and MifR respectiv ely could restore motility in the Pf0-1 fleQ mutant and found that the add ition of glutamate restored motility. However\, deletion of aauR did not a bolish motility restoration\, indicating that a different bEBP was importa nt. Surprisingly\, deletion of ntrC rendered glutamate unable to promote m otility restoration\, demonstrating that in the presence of glutamate wild type NtrC can functionally replace FleQ in P. fluorescens. Measurement of transcription of the gene flhA which is normally FleQ-controlled confirmed that in the presence of glutamate\, NtrC is capable of regulating express ion of flagella genes. This research looks to provide an insight on how cr osstalk between different regulatory pathways can increase the adaptabilit y of bacteria in complex natural environments.

Event page: https://www.umassd.edu/events/cms/biology-master-thesis-defense -by-sharon-jacob.php

DTSTAMP:20260421T165509 DTSTART;TZID=America/New_York:20260513T120000 DTEND;TZID=America/New_York:20260513T130000 LOCATION:SENG-118 SUMMARY;LANGUAGE=en-us:Biology Master Thesis Defense by Sharon Jacob UID:5baad8ad2907b7179944f4408ffe8d80@www.umassd.edu END:VEVENT END:VCALENDAR