Genetic and environmental modulation of phenotypic variation in Arabidopsis thaliana [Elektronische Ressource] / vorgelegt von Sridevi Sureshkumar

Dr. Sureshkumar Balasubramanian

Sujets

• Biologie

Informations

• Publié par: eberhard_karls_universitat_tubingen
• Publié le: 01 janvier 2011
• Nombre de lectures: 8
• Langue: English
• Poids de l'ouvrage: 14 Mo

Extrait

Genetic and environmental
modulation of phenotypic variation
in Arabidopsis thaliana
Dissertation
der Mathematisch-Naturwissenschaftlichen Fakultät
der Eberhard Karls Universität Tübingen
zur Erlangung des Grades eines
Doktors der Naturwissenschaften
(Dr. rer. nat.)
vorgelegt von
Mrs Sridevi Sureshkumar
aus Dharmapuri, Indien
Tübingen
2011Tag der mündlichen Qualifikation: 26. 01. 2011
Dekan : Prof. Dr. Wolfgang Rosenstiel
1.Berichterstatter: Prof. Dr. Detlef Weigel
2.Berichterstatter: Prof. Dr. Klaus HarterSUMMARY ............................................................................................................7
INTRODUCTION .................................................................................................11
Phenotypic variation ..............................................................................................................................11
Genetic basis for natural variation in Arabidopsis thaliana ...................................................................13
Genetic basis for flowering time variation ............................................................................................14
Genetic basis for temperature regulation of flowering time ..................................................................15
Lessons from hidden genetic variation ..................................................................................................15
CHAPTER: 1 .......................................................................................................17
Quantitative genetic analysis of flowering time variation in wild strains of Arabidopsis thaliana. ......17
Summary ....................................................................................................................................................17
Introduction ................................................................................................................................................19
Arabidopsis is a useful model organism to study genetic variation. .....................................................19
Four different major genetic pathways controlling flowering time ......................................................20
Flowering response to changes in ambient temperature in Arabidopsis. ..............................................21
Natural variation in flowering responses of Arabidopsis. .....................................................................21
Results summary ...................................................................................................................................24
Materials and Methods ...............................................................................................................................25
Flowering time measurements ..............................................................................................................26
DNA Analyses .......................................................................................................................................26
Statistical analyses and QTL mapping ..................................................................................................27
Results. .......................................................................................................................................................28
Genetic analysis of early flowering accessions at short days ................................................................28
Genetic architecture for earlier flowering under short days. 30
QTL analysis of flowering time variation using RILs. .........................................................................31
QTL analysis of flowering time in Est-1/Col-0 RILs ............................................................................32
QTL analysis of flowering time in Nd-1 x Col RILs 33
QTL analysis of flowering time in C24 x Col-0 RILs ..........................................................................35
QTL analysis of leaf shape i-0 RILs ..................................................................................35
Discussion ..................................................................................................................................................36
Genetic basis of flowering time variation in short days is complex .....................................................36
Days to flowering and total leaf number may not be correlated all the time. .......................................37
FLM may be the major floral repressor in short days as opposed to FLC ............................................38
Genetic architecture of leaf shape revealed by transgression in C24/Col-0 recombinant inbred lines. 39
Contributions ..............................................................................................................................................40
Other contributions related to flowering time publications ..................................................................40
CHAPTER: 2 .......................................................................................................41
Allelic variation in PHYTOCHROME C contributes to natural variation in flowering and light
responses of Arabidopsis thaliana. ..............................................................................................................41
Summary ....................................................................................................................................................41
Introduction ................................................................................................................................................43
Natural variation in phytochromes ........................................................................................................43
Materials and Methods ...............................................................................................................................44
Plant material, growth conditions and DNA work ................................................................................44
Hypocotyls length and flowering time measurements ..........................................................................45
Sequence analysis ..................................................................................................................................45
Linkage analysis ....................................................................................................................................46
Expression Studies ................................................................................................................................46RNA isolation and expression studies ...................................................................................................47
Phylogenetic analysis ............................................................................................................................47
Statistical analyses ................................................................................................................................48
Results ........................................................................................................................................................48
Mapping and identification of the molecular lesion in Fr-2 ..................................................................48
Fr-2 PHYC is highly polymorphic and shares the polymorphisms with Ler ........................................51
Analysis of allelic variation at PHYC locus ..........................................................................................53
Functional significance of allelic variation at PHYC ...........................................................................54
Population genetics and latitudinal cline ...............................................................................................56
Alternative Splicing of PHYC ..............................................................................................................58
Discussion ..................................................................................................................................................60
Combinatorial approach for faster detection of genes underlying quantitative traits ...........................60
Two functionally distinct PHYC haplotype groups ..............................................................................60
Evolution of PHYC in Arabidopsis thaliana .........................................................................................61
Alternative splicing and its functional relevance ..................................................................................61
Photoreceptors as agents for conferring phenotypic variation ..............................................................62
Contributions ..............................................................................................................................................62
CHAPTER: 3 .......................................................................................................74
A genetic defect caused by a triplet repeat expansion in Arabidopsis thaliana ......................................74
Summary ....................................................................................................................................................74
Introduction .....................................................................................