BrachyBioMutantPlants StudentLaboratory Name Background: Innature,randommutationsoccurwhenDNAchanges.Thesemutationscan becausedbymistakesmadeduringreplication,orbymutagenic agentssuchasuv radiation, or certain chemicals. Organisms that carry these mutations may appear different than others of their species. This may lead to variation within a species. Somenewtraitsmayhelpanorganismsurviveinitsenvironment,whilesomemayhurt theorganism schancesofsurvival. You will be given seeds from a plant called Brachypodium distachyon ( Brachy ), which has been mutagenized with the chemical Ethyl Methanesulfonate (EMS) that is known to produce random mutations by changing onebasepairatatime.sincebrachyhas270millionbasepairs,thesemutationsmay occuranywhere.largeregionsofdnaarenonbcoding,andmanymutationsmaybe silent.therefore,thereisastrongpossibilitythatthemutationswillnotresultinany newtraitthatanobservercaneasilydetect.however,manynewtraitshavealready beendiscoveredusingthismethod. Yourjobwillbetogrowplantsfromtheseedsofoneofthesemutatedplants, compare them against the known normal or wild type Brachy, and hypothesize whetheranynewtraityoudiscoverwillhelptheorganism schancesofsurvival,hurtit, orhavenoadaptivevalueatall. Materials: 12EMStreatedseeds SoilLiner PlantLabels Marker MiracleSGrowPottingSoil Thermometer LuxMeter HumidityDetector LightBank I.PlantingSeeds: 1. Fillcleanasoillinerwithnewpottingsoil. 2. Addwaterasneededuntilthesoilisthoroughlysaturated. 3. Fillouttheplanttagwiththefollowinginformation a. Sideone:FamilyNumber,dateplanted b. Sidetwo:Yourname 4. Usingapencil,place4holesineachsectionofthesoilliner:onein eachcorner. 5. Usingforceps,placeoneseedineachhole,thengentlycoverwith soil. 6. Placeyoursoilliner,withits12seedsandplanttagintoatray.
7. Add water to the bottom of the tray, keeping the water level just above the ribs onthebottomofthetray.checkyourwaterlevelsdaily,andaddwateras needed. 8. Placethetrayunderthelightbank 9. Recordtheenvironmentalconditionsinthedatatable. II.Screen1: 1. Afewdaysaftergermination(plantsareabout4S8cmhigh)observetheplants. 2. Recordhowmanyhavegerminatedandtheircharacteristicsascomparedtothe wildtype(wt).refertothemutantphotolibraryonthebtiwebsiteforspecific termsforeachtrait. 3. Recordtheenvironmentalconditionsinthedatatable. III.Screen2: 1. About three weeks after planting (plants are about 20 cm high) observe the plants. 2. Branchingofwildtypeplantshasnowoccurred,andnewtraitsmaybeevident. 3. Onceagain,refertothemutantlibraryforanynecessaryclarification,andrecord your observations in your data table. Begin to check plants daily for flowering andrecordthedaytheyflower. 4. Recordtheenvironmentalconditionsinthedatatable. IV.Screen3: 1. About7weeksafterplanting,thewildtypeshouldhavematuredandproduced seeds. 2. Checkfortheappearanceofanynewtraits,aswellasthedevelopmentofthe previouslyidentifiedtraits.recordallinformationinthedatatable. CollectionofSeeds: 1. Ifyouhadanyphenotypicmutations,takeapictureofthemalongsidethefamily #tagandaruler. 2. Collectandcounttheseedsfromthoseplants. 3. Recordthenumberofseeds,andplacetheminanewenvelopewiththefamily number. BTIScienceEducationPrograms StudentLab 2
Questions: 1. Calculate the percentage of your seed were mutants by dividing the number of mutants by the total number of seeds that germinated then multiply by 100. % 2.Howdidyourmutationratecomparetoothersinyourclass?Whydoyouthinkthis isso? 3.Howcananydifferencesinnewtraitsbetweenfamiliesbeexplained? 4.Observeyourmutants(s),oroneprovidedforyoubytheteacher.Howdoesitdiffer fromthewildtype? 5.Doyouthinkthisnewtraitisbeneficial?Whyorwhynot? 6. Calculate the average number of days it took for your wild type plants to flower. days. Werethereanymutantsintheclasswithadifferentfloweringtime? 7. How many seeds did the mutant produce under these laboratory conditions? How does this compare to the wild type s average seed productionunderthesameconditions? 8.Whatisthepurposeofthewildtypeinthisactivity? 9. Do you think this plant will be more, less, or equally successful as the wild type? Explainwhy. BTIScienceEducationPrograms StudentLab 3
10.WhatwouldyouexpecttohappentothefrequencyofthismutationintheBrachy populationovertime? 11.What,ifanyclimateconditionswouldthismutationsurviveexceptionallywell? Family# PlantingDate: o C %Humiditymin /max Lux ScreenOne: o C %Humiditymin /max Lux ScreenTwo: o C %Humiditymin /max Lux ScreenThree: o C %Humiditymin /max Lux BTIScienceEducationPrograms StudentLab 4
Seed ScreenOne ScreenTwo ScreenThree Flowering Date 1 #of Seeds Harvested 2 3 4 5 6 7 8 9 10 11 12 BTIScienceEducationPrograms StudentLab 5
BTIScienceEducationPrograms StudentLab 6 GlossaryofStandardBrachypodiumPhenotypeTerms Phenotype PhenotypeSub Category MutantDescriptions Color Green Dark Pale Yellow Dark Pale Variegated Horizontal Vertical Other Virescent SlowGreening White Albino Other Brown Red Disease Necrosis Other TissueColor LesionType #ofleavesinfected Other FloweringTime Development DaystoFlower Early Late Architecture Branching Less More Flower AbnormalShape LessSpikelets MoreSpikelets Large Small #offlorets Sterility Leaf Drooping Upright Hairy Smooth Long Short Narrow Wide Serrated Spiral Size Dwarf(wideleaf) Tiny(narrowleaf) Small
Big Stem Long Short Wide Narrow Spiral Hairy Smooth Abnormal Roots Other CompilingClassData: Didyouhaveanymutantsinyourfamily? Ifyoudid,yourdataisimportanttothescientistsattheBoyceThompson Institute.Takeapictureofyourmutant.Makesurethetagwiththefamily numberisclearlyvisible,aswellasaruler(metric)toillustratethesizeofthe plant.youwilluploadyourdataandpicturesofyourmutantsonthebrachybio DatacentralWebpage. OptionalExtensions: Reporting: ScientistsreallydowantyourinputByenlistingthehelpofstudentslike youincataloguingallthenewtraitsthatariserandomlythroughemstreatment, scientistscangetfarmoreworkdonethanbyworkingalone.ifanymutanttrait appeared within your family of seeds, prepare a brief Power Point presentation reportingyourfindings.thepresentationshouldinclude: Slide1:Name,School,BrachyFamilyNumber Slide2:Adescriptionofthetrait,thepercentageoftheplantseffected,Number ofseedsproducedpermutantplant Slide3:Asummaryoftheabioticconditionsintheclassroomduringthecourse of the experiment. This is important because sometimes differences in temperature,lightorhumiditycanaffectthewaygenesareexpressed. Slide4:Photosofthemutatedplant,photoofawildtypeplant,andarulerfor comparison BTIScienceEducationPrograms StudentLab 7
Slide5:Adiscussionofwhetheryoufeelthisnewtraithasanyadaptivevalue. Include your reasoning, as well as whether you believe the trait would be beneficialtoaplantinnatureorifitmightbeatraitthatscientistsmaywantto useinselectivebreeding. Heredity&Evolution: MutationshavecontributedtovarietyoflifeonEarthNewtraitsmaystart withamutation.oftenmutationsareharmful,andtheorganismsthatdisplay themdonotcompetewell.sometimesanewtraithelpstheorganismthat inheritsittosurvive,andinturnhavemoreoffspringwiththattrait.humans oftenpurposelybreedorganismswithdesiredtraits(artificialselection).you havejustcompletedaprojectthathelpeddocumentnewmutationsandthe characteristicstheyproduce. WillthenewgenesgeneratedbytheEMStreatmentoftheBrachyseeds bepassedontofuturegenerations? CanyouselectforthetraittoproduceanentirelyNEWvarietyof Brachypodia? Willtheseedsofyourmutantgrowbetterunderdifferentconditions? Basedonyourknowledgeandtheproceduresfromthisactivity,developa researchprojectthatwillansweroneofthesequestions,oroneofyourown. BTIScienceEducationPrograms StudentLab 8