Práce bude zaměřená na odhalení mechanismu adaptace přírodních populací Arabidopsis arenosa k hadcovému substrátu. Bude kombinovat experimentální přístupy "common garden" a populační genomiky. Pomocí metody bulk segregarnt analysis aplikované na geneticky variabilní populaci segregující hadcovou adaptaci (F2 populace získaná křížením původně hadcové a nehadcové populace) kombinované s celogenomickým sekvenováním budou identifikovány odhaleny části genomu které zodpovédají za fitness odpověď k toxickému hadcovému substrátu. Tyto kandidátní regiony budou následně přeloženy s genomickými kandidáty selekce získanými divergenčními skeny přírodních populací (získány v rámci souvisejícího PhD projektu) a bude testována signifikantní asociace mezi genomickými regiony zodpovídající za fitness a za divergenci původních populací. Práce tak poskytne unikátní experimentálně ekologicky-genomický vhled do architektury adaptace k extrémnímu prostředí u rostlin.
Preliminary scope of work in English
Arabidopsis arenosa represents a promising model for studying the mechanisms underlyingthe adaptation to serpentine soil. Genetic basis of serpentine adaptation is still poorly knownand A. arenosa possesses many advantages as a model to improve that knowledge. The firststep of this study was to reveal the presence of a local adaptation to serpentine soil in apopulation of A. arenosa. To do so, I analysed the data from a reciprocal transplant experimentrealized between a Czech pair of serpentine – non-serpentine populations and I explored thephenotypes associated with substrate adaptation. Subsequently, I run experimental crossingbetween serpentine - non-serpentine parents and I studied the expression of fitness traits inF2 plants growing in serpentine in order to estimate genetic architecture of the adaptation.I confirmed the presence of a local adaptation, with the population of serpentine originperforming better than the non-serpentine population in the serpentine substrate of origin,further associated with accumulation of heavy metals in the leaves. Analyses of the soilcomposition revealed differences in heavy metal and nutrient contents, Ca/Mg ratio and pHbetween the two localities. Those environmental parameters well corresponded with thefunction of the candidate genes identified in previous population genomic studies ofserpentine adaptation in Arabidopsis arenosa. In the second part, I estimated the effectivenumber of loci underlying the serpentine adaptation which was of 9 to 24 loci. Those resultsare slightly lower than the candidate numbers identified in serpentine Arabidopsis previouslyby population genomic approaches, likely as an effect of neglecting the linkage between loci inmy method or by false positives included in the published candidate lists.In the future, by using a bulk segregant analysis based on my F2 mapping population, we willbe able to compare the candidate for adaptation with the previously identified candidategenes in order to confirm the genes underlying adaptation of Arabidopsis arenosa toserpentine soil.
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