Local and systemic resistance in Arabidopsis thaliana in response to Pseudomonas syringae [Elektronische Ressource] : impact of light and phytosterols / vorgelegt von Thomas Griebel

Thomas Carlyle

Informations

• Publié par: julius-maximilians-universitat_wurzburg
• Publié le: 01 janvier 2010
• Nombre de lectures: 15
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Local and systemic resistance in Arabidopsis
thaliana in response to Pseudomonas syringae:
impact of light and phytosterols





Dissertation zur Erlangung des
naturwissenschaftlichen Doktorgrades
der Julius-Maximilians-Universität Würzburg







vorgelegt von
Thomas Griebel
aus
Bad Neustadt an der Saale


Würzburg 2010























Eingereicht am: …………………………….


Mitglieder der Promotionskommission:

Vorsitzender: Prof. Dr. Thomas Dandekar
Gutachter 1: PD Dr. Jürgen Zeier
Gutachter 2: Prof. Dr. Werner Kaiser

Tag des Promotionskolloquiums: …………………………….

Doktorurkunde ausgehändigt am: …………………………….

Content
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1. SUMMARY ....................................................................................................................................................... 1
2. ZUSAMMENFASSUNG .................................................................................................................................. 3
3. INTRODUCTION............................................................................................................................................. 5
3.1 PLANT DEFENCE AGAINST PATHOGENS .......................................................................................................... 5
3.1.1 Non-host resistance ............................................................................................................................... 5
3.1.2 Preformed defence................................................................................................................................. 6
3.1.3 Induced basal defence ........................................................................................................................... 7
3.1.4 Susceptibility requires suppression of basal resistance ........................................................................ 9
3.1.5 Gene-for-gene resistance..................................................................................................................... 12
3.1.6 Induced metabolic defence pathways .................................................................................................. 13
3.1.7 Systemic acquired resistance (SAR) .................................................................................................... 17
3.2 THE USED MODEL PATHOSYSTEMS............................................................................................................... 19
3.2.1 The pathosystem Arabidopsis thaliana - Pseudomonas syringae........................................................ 19
3.2.1.1 Arabidopsis thaliana as model plant................................................................................................ 20
3.2.1.2 Pseudomonas syringae as a model pathogen ................................................................................... 20
3.2.2 The pathosystem Arabidopsis thaliana - Botrytis cinerea ................................................................... 21
3.3 LIGHT AND DEFENCE ................................................................................................................................... 22
3.5 PLANT PHOTORECEPTORS ............................................................................................................................ 24
3.5.1 The phytochromes................................................................................................................................ 24
3.5.2 The cryptochromes .............................................................................................................................. 25
3.5.3 The phototropins.................................................................................................................................. 26
3.5.4 Putative Photoreceptors ...................................................................................................................... 27
3.6 PHYTOSTEROLS ........................................................................................................................................... 28
3.6.1 Biosynthesis......................................................................................................................................... 29
3.6.2 Functions............................................................................................................................................. 31
3.7 REFERENCES................................................................................................................................................ 33
4. AIM OF THE WORK .................................................................................................................................... 41
5. LIGHT REGULATION AND DAYTIME DEPENDENCY OF INDUCIBLE PLANT DEFENCES IN
ARABIDOPSIS: PHYTOCHROME SIGNALLING CONTROLS SYSTEMIC ACQUIRED
RESISTANCE RATHER THAN LOCAL DEFENCE.................................................................................... 43
5.1 SUMMARY ................................................................................................................................................... 45
5.2 INTRODUCTION ............................................................................................................................................ 45
5.3 RESULTS...................................................................................................................................................... 48
5.3.1 Plant defences and resistance depend on the daytime of inoculation.................................................. 48 Content
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5.3.2 Photoreceptor signalling only moderately affects induction of Arabidopsis defences at sites of Psm (±
avrRpm1) inoculation................................................................................................................................... 51
5.3.3 SAR requires functional phytochrome photoperception but is independent of cryptochrome and
phototropin signalling .................................................................................................................................. 54
5.4 DISCUSSION................................................................................................................................................. 56
5.4.1 Daytime dependency of resistance responses...................................................................................... 56
5.4.2 Cross-talk of photoreceptor signalling and plant defence................................................................... 58
5.5 MATERIALS AND METHODS......................................................................................................................... 61
5.5.1 Plant Materials and Growth Conditions ............................................................................................. 61
5.5.2 Growth of Plant Pathogens and Inoculation....................................................................................... 61
5.5.3 Daytime experiments ........................................................................................................................... 62
5.5.4 Characterization of Systemic Acquired Resistance ............................................................................. 62
5.5.5 Analysis of Gene Expression ............................................................................................................... 62
5.5.6 Determination of Defence Metabolites................................................................................................ 62
5.5.7 Quantification of microscopic HR lesions and assessment of H O production ................................. 63 2 2
5.6 REFERENCES................................................................................................................................................ 63
6. MEMBRANE STIGMASTEROL ACCUMULATION ENHANCES PLANT DISEASE
SUSCEPTIBILITY TO BACTERIAL PATHOGENS.................................................................................... 67
6.1 SUMMARY ................................................................................................................................................... 69
6.2 INTRODUCTION ............................................................................................................................................ 70
6.3 RESULTS...................................................................................................................................................... 72
6.3.1 β-sito- to stigmasterol conversion via CYP710A1 constitutes a significant metabolic process in P.
syringae-inoculated Arabidopsis leaves....................................................................................................... 72
6.3.2 Mutational defects in CYP710A1 lead to increased resistance towards P. syringae .......................... 75
6.3.3 Stigmasterol formation is triggered by recognition of bacterial PAMPs ...................................