Arbuscular mycorrhizal (AM) fungal diversity of arid lands: From AM fungal species to AM fungal communities Inauguraldissertation zur Erlangung der Würde eines Doktors der Philosophie vorgelegt der Philosophisch-Naturwissenschaftlichen Fakultät der Universität Basel von Sarah Symanczik aus Österreich Basel, 2016 Originaldokument gespeichert auf dem Dokumentenserver der Universität Basel edoc.unibas.ch 1 Genehmigt von der Philosophisch-Naturwissenschaftlichen Fakultät auf Antrag von Prof. Dr. Andres Wiemken, Prof. Dr. Thomas Boller Basel, den 25.März 2014 Prof. Dr. Jörg Schibler 2 TABLE OF CONTENTS Table of contents Acknowledgements ..................................................................................................................................... 6 Summary ...................................................................................................................................................... 7 1 General Introduction ............................................................................................................................. 9 1.1 Mycorrhizal Symbiosis ....................................................................................................................... 9 1.2 Arbuscular Mycorrhiza (AM) ........................................................................................................... 12 1.2.1 Introduction ................................................................................................................................ 12 1.2.2 Arbuscular mycorrhizal fungi .................................................................................................... 12 1.2.3 Plants forming arbuscular mycorrhiza ....................................................................................... 13 1.2.4 Characteristics and establishment of the AM symbiosis ............................................................ 13 1.3 Classification of AM fungi ............................................................................................................... 15 1.3.1 Classification and Phylogeny ..................................................................................................... 15 1.3.2 Identification of AM fungi ......................................................................................................... 18 1.3.3 “Species concept” in the Glomeromycota .................................................................................. 19 1.4 Functional aspects of the AM symbiosis .......................................................................................... 19 1.5 AM fungi and ecosystem functioning ............................................................................................... 21 1.5.1 Importance of AM fungal diversity and co-occurrence of AM fungi ........................................ 21 1.5.2 AM fungal community composition .......................................................................................... 23 1.5.3 Invasion in AM fungal communities.......................................................................................... 24 1.6 AM symbiosis in arid environments such as desert ecosystems ....................................................... 25 1.6.1 Characteristics of desert ecosystems .......................................................................................... 25 1.6.2 Multifunctional role of AM fungi on plant drought tolerance ................................................... 25 1.6.3 Impact of drought on AM fungi ................................................................................................. 27 1.6.4 Application of AM fungi as biotechnological tool .................................................................... 27 1.7 Significance of plant aquaporins: Role and regulation ..................................................................... 28 1.7.1 Description ................................................................................................................................. 28 1.7.2 Aquaporin regulation upon mycorrhization ............................................................................... 30 1.8 Aims of the thesis .............................................................................................................................. 32 2 Three new species of arbuscular mycorrhizal fungi discovered at one location in a desert of Oman: Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus .......................... 34 2.1 Abstract ............................................................................................................................................. 35 2.2 Introduction ....................................................................................................................................... 36 3 TABLE OF CONTENTS 2.3 Material and Methods ....................................................................................................................... 37 2.4 Results ............................................................................................................................................... 41 2.5 Taxonomy ......................................................................................................................................... 44 2.6 Discussion ......................................................................................................................................... 54 2.7 Aknowledgements ............................................................................................................................. 55 3 Isolation and identification of desert habituated arbuscular mycorrhizal fungi newly reported from the Arabian Peninsula ..................................................................................................................... 56 3.1 Abstract ............................................................................................................................................. 57 3.2 Introduction ....................................................................................................................................... 58 3.3 Materials and Methods ...................................................................................................................... 60 3.4 Results and discussion ...................................................................................................................... 62 3.5 Conclusions ....................................................................................................................................... 67 3.6 Acknowledgments ............................................................................................................................. 67 4 The impact of different water regimes on an experimental community of four desert arbuscular mycorrhizal fungal (AMF) species, as affected by addition of a potentially invasive AMF species, Rhizophagus irregularis ............................................................................................................................ 69 4.1 Abstract ............................................................................................................................................. 70 4.2 Introduction ....................................................................................................................................... 71 4.3Materials and Methods ....................................................................................................................... 72 4.4 Results ............................................................................................................................................... 76 4.5 Discussion ......................................................................................................................................... 79 4.6 Acknowledgments ............................................................................................................................. 83 4.7 Supplementary data ........................................................................................................................... 84 5 Functional characteristics of Rhizophagus arabicus in comparison with Rhizophagus irregularis - a battle as best symbiont under changing water regimes ...................................................................... 87 5.1 Summary ........................................................................................................................................... 88 5.2 Introduction ....................................................................................................................................... 89 5.3 Materials and Methods ...................................................................................................................... 90 5.4 Results ............................................................................................................................................... 92 5.5 Discussion ......................................................................................................................................... 95 5.6 Acknowledgments ............................................................................................................................. 96 5.7 Supplementary data ........................................................................................................................... 97 4 TABLE OF CONTENTS 6 The potential of using native symbiotic mycorrhizal