The structure and function of ray and axial parenchyma in woody seed plants Dissertation Zur Erlangung des Doktorgrades Dr. rer. nat. der Fakultät für Naturwissenschaften der Universität Ulm vorgelegt von Hugh Robert Morris aus Irland Ulm 2016 The structure and function of ray and axial parenchyma in woody seed plants Dissertation Zur Erlangung des Doktorgrades Dr. rer. nat. der Fakultät für Naturwissenschaften der Universität Ulm vorgelegt von Hugh Robert Morris aus Irland Ulm 2016 Amtierender Dekan: Prof. Dr. Peter Dürre 1. Gutachter: Prof. Dr. Steven Jansen 2. Gutachter: Prof. Dr. Stefan Binder Date of award Dr. rer. nat. (Magna Cum Laude) awarded to Hugh Robert Morris on 20th of July, 2016 Cover picture: A stitched example I made of a transverse section of Fraxinus excelsior stained for starch in Lugol’s solution Table of Contents Part I ..................................................................................................................................................................... 1 General definition and function of parenchyma cells in plants .................................................................... 2 The contents of parenchyma in relation to function .................................................................................... 2 Parenchyma of the secondary xylem: an overview ...................................................................................... 3 Symplastic pathways between the secondary phloem and xylem ............................................................... 4 The longevity of living cells in the secondary xylem and the formation of heartwood .............................. 10 The functions of RAP in secondary xylem ................................................................................................... 11 Long distance water transport and RAP ..................................................................................................... 12 Defence against pathogens and RAP .......................................................................................................... 15 RAP and mechanical properties of the secondary xylem ........................................................................... 18 Aims of the thesis ........................................................................................................................................... 19 The research topics and permissions .............................................................................................................. 20 Summary of chapters ..................................................................................................................................... 21 Chapter 1: A global analysis of parenchyma tissue fractions in secondary xylem of seed plants .............. 21 Chapter 2: The amount of parenchyma and living fibres affects storage of non-structural carbohydrates in young stems and roots of temperate trees ............................................................................................ 23 Chapter 3: Secondary xylem parenchyma – from classical terminology to functional traits ..................... 24 Conclusions and future prospects ................................................................................................................. 25 References ...................................................................................................................................................... 28 Part II .................................................................................................................................................................. 51 A global analysis of parenchyma tissue fractions in secondary xylem of seed plants .................................... 52 Abstract ...................................................................................................................................................... 53 Introduction ................................................................................................................................................ 54 Materials and Methods .............................................................................................................................. 58 Compilation of the global parenchyma dataset ..................................................................................... 58 Validation of the dataset ........................................................................................................................ 59 Climate data ............................................................................................................................................ 60 Statistical analyses .................................................................................................................................. 61 Results ........................................................................................................................................................ 62 Overview of the core dataset ................................................................................................................. 62 Validation of the dataset ........................................................................................................................ 62 Climate and RAP fractions ...................................................................................................................... 65 Discussion ................................................................................................................................................... 72 RAP fractions in relation to NSC storage capacity .................................................................................. 73 RAP fractions and drought stress ............................................................................................................ 73 RAP fractions and temperature .............................................................................................................. 74 RAP fractions as a defence system ......................................................................................................... 74 RAP and mechanical properties .............................................................................................................. 75 General Conclusion .................................................................................................................................... 76 Acknowledgements .................................................................................................................................... 76 Author contributions .................................................................................................................................. 77 References ...................................................................................................................................................... 78 Supporting Information for New phytologist.................................................................................................. 90 Part II ................................................................................................................................................................ 106 The amount of parenchyma and living fibres affects storage of non-structural carbohydrates in young stems and roots of temperate trees ............................................................................................................. 107 Abstract .................................................................................................................................................... 108 Introduction .............................................................................................................................................. 109 Materials and Methods ............................................................................................................................ 112 Plant material ........................................................................................................................................ 112 NSC analyses ......................................................................................................................................... 114 Wood anatomy and starch distribution ................................................................................................ 115 Statistical analyses ................................................................................................................................ 118 Results ...................................................................................................................................................... 118 NSC concentrations ............................................................................................................................... 118 RAP and LFs anatomy ............................................................................................................................ 120 Starch localisation ................................................................................................................................. 121 Relationship between NSC and RAP ..................................................................................................... 123 Discussion ................................................................................................................................................. 125 Acknowledgements .............................................................................................................................