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,Thesis/Dissertations DESCRIPTION:Advisor: Dr. Mark Silby mark.silby@umassd.edu Committee: Dr. Ch ristopher Brigham, Dr. Robert Drew Abstract: Rhizobacteria such as Pseudom onas fluorescens Pf0-1 are important contributors to plant health due to t heir involvement in nutrient uptake, regulation of plant immunity, and inh ibition of pathogens. P. fluorescens Pf0-1 mediates movement by using micr oscopic hair-like structures called flagella. Flagella synthesis is contro lled by the bacterial enhancer binding protein (bEBP) FleQ; fleQ mutants a re unable to swim. Taylor et al., (2015) showed that fleQ mutants eventual ly regain motility due to new mutations in ntrB and ntrC which result in e levated activation of NtrC and off-target binding of the bEBP NtrC to FleQ -controlled promoters. We hypothesized that if mutations that activate bEB Ps can lead to crosstalk between regulatory networks, environmental signal s that activate bEBPs may also influence crosstalk in a post-translational manner. We tested whether glutamate or alpha ketoglutarate which are pred icted to activate AauR and MifR respectively could restore motility in the Pf0-1 fleQ mutant and found that the addition of glutamate restored motil ity. However, deletion of aauR did not abolish motility restoration, indic ating that a different bEBP was important. Surprisingly, deletion of ntrC rendered glutamate unable to promote motility restoration, demonstrating t hat in the presence of glutamate wildtype NtrC can functionally replace Fl eQ in P. fluorescens. Measurement of transcription of the gene flhA which is normally FleQ-controlled confirmed that in the presence of glutamate, N trC is capable of regulating expression of flagella genes. This research l ooks to provide an insight on how crosstalk between different regulatory p athways can increase the adaptability of bacteria in complex natural envir onments.\nEvent page: https://www.umassd.edu/events/cms/biology-master-the sis-defense-by-sharon-jacob.php X-ALT-DESC;FMTTYPE=text/html:

Advisor: Dr. Mark Silby mark.si lby@umassd.edu

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Committee: Dr. Christopher Brigham\, Dr. Robert Dre w

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Abstract: Rhizobacteria such as Pseudomonas fluorescens Pf0-1 ar e important contributors to plant health due to their involvement in nutri ent uptake\, regulation of plant immunity\, and inhibition of pathogens. P . fluorescens Pf0-1 mediates movement by using microscopic hair-like struc tures called flagella. Flagella synthesis is controlled by the bacterial e nhancer binding protein (bEBP) FleQ\; fleQ mutants are unable to swim. Tay lor 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 bEBP s may also influence crosstalk in a post-translational manner. We tested w hether glutamate or alpha ketoglutarate which are predicted to activate Aa uR and MifR respectively could restore motility in the Pf0-1 fleQ mutant a nd found that the addition of glutamate restored motility. However\, delet ion of aauR did not abolish motility restoration\, indicating that a diffe rent bEBP was important. Surprisingly\, deletion of ntrC rendered glutamat e unable to promote motility restoration\, demonstrating that in the prese nce of glutamate wildtype NtrC can functionally replace FleQ in P. fluores cens. Measurement of transcription of the gene flhA which is normally FleQ -controlled confirmed that in the presence of glutamate\, NtrC is capable of regulating expression of flagella genes. This research looks to provide an insight on how crosstalk between different regulatory pathways can inc rease the adaptability of bacteria in complex natural environments.

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

DTSTAMP:20260522T154057 DTSTART;TZID=America/New_York:20260610T100000 DTEND;TZID=America/New_York:20260610T110000 LOCATION:LIB-314 SUMMARY;LANGUAGE=en-us:Biology Master Thesis Defense by Sharon Jacob UID:757bf7af2036b28c30282b0dd0690197@www.umassd.edu END:VEVENT END:VCALENDAR