CENTENNIAL HONORS COLLEGE
Western Illinois University
Undergraduate Research Day 2016
PosterPresentation
TheExpressionofFattyAcidDesaturaseGenesinArabidopsisPlantsThatHaveBeenExposed
toOzone
JessicaJirik
FacultyMentor:MeshackAfitlhile
Biology
Ozone(O3)isaveryreactiveformofoxygenthatisfoundnaturallyintheatmosphere.Intheirinternal
structure,plantsareequippedwithnaturalmechanismssuchasspecificenzymesandlipidsthatbreak
downreactiveoxygenspecies,whichareproducedbyozoneandmaydamagemembranes.Whenlevels
ofreactiveoxygenspeciesaretoohighinsidetheleaves,theplants’defensebreaksdown,andthisis
shownbythelipidbreakdownandsubsequentdecreaseinlevelsofthefattyacid,linoleicacid(18:3).
We are interested in evaluating how high levels of ozone affects synthesis of the major chloroplast
lipids, whose synthesis is dependent on nuclear-encoded enzymes. Our preliminary studies show that
Arabidopsisplantsexposedtoozoneforthreehourshavedecreasedlevelsofthefattyacid,roughanic
acid(16:3),whichisfoundinonemajorchloroplastlipid.Theobjectiveofourstudyistocomparethe
totalfattyacidcompositionandlipidcontentofthewildtypeandmutantplants.Wehypothesizethat
genes,whichencodeenzymesinthelipidsynthesispathway,willbedown-regulatedinozonetreated
plants. In order to address this, we will measure the abundance of specific messenger RNA from
untreated plants and ozone-exposed plants. Total RNA will be extracted from untreated and ozone
exposed plants, then we will synthesize complementary DNA, and set quantitative polymerase chain
reaction.Thegoalistorelatetheexpressionofgenesinthelipidsynthesispathwaytotheaccumulation
offattyacidsandlipidcontentunderozone-treated