The effect of plant hormones on phenolic production in Kauri trees Blair Shilton School of Science Faculty of Health and Environmental Sciences A thesis submitted to Auckland University of Technology in partial fulfilment of the requirements for Master of Science February 2017 Table of Contents List of Tables ......................................................................................................................................... iv List of Figures ........................................................................................................................................ vi Attestation of authorship ...................................................................................................................... viii Acknowledgments .................................................................................................................................. ix Abstract ................................................................................................................................................... 1 Chapter 1 ................................................................................................................................................. 2 Introduction ............................................................................................................................................. 2 1.1 Agathis australis ............................................................................................................................ 3 1.2 Phytophthora ................................................................................................................................. 3 1.2.1 Phytophthora agathidicida .................................................................................................... 4 1.2.2 Phytophthora cinnamomi ....................................................................................................... 7 1.3 Types of defence ......................................................................................................................... 12 1.3.1 Structural defences ............................................................................................................... 12 1.3.2 Chemical defences ............................................................................................................... 13 1.3.3 Jasmonic acid ....................................................................................................................... 15 1.3.4 Salicylic acid ........................................................................................................................ 16 1.4 Phenolic compounds ................................................................................................................... 17 1.4.1 Tannins ................................................................................................................................. 17 1.4.2 Lignin ................................................................................................................................... 20 Chapter 2 ............................................................................................................................................... 23 Materials and Methods .......................................................................................................................... 23 2.1 Leaf treatment ............................................................................................................................. 23 2.2 Phenolic assays ........................................................................................................................... 26 2.2.1 Soluble phenolics assay ....................................................................................................... 26 2.2.2 Insoluble phenolics assay ..................................................................................................... 27 2.2.3 Tannin assay ......................................................................................................................... 28 2.2.4 Lignin assay ......................................................................................................................... 29 2.3 Culture experiments .................................................................................................................... 30 2.3.1 Detached leaf assay .............................................................................................................. 30 2.3.2 Phytophthora Culture experiments ...................................................................................... 31 Chapter 3 ............................................................................................................................................... 34 Results ................................................................................................................................................... 34 3.1 Phenolics ..................................................................................................................................... 34 3.1.1 Methyl jasmonate ................................................................................................................. 34 3.1.2 Salicylic acid ........................................................................................................................ 45 3.2 Culture Results ............................................................................................................................ 55 3.2.1 Detached Leaf Assays .......................................................................................................... 55 3.2.2 Culture plate assays .............................................................................................................. 58 Chapter 4 ............................................................................................................................................... 62 4.1 Discussion ....................................................................................................................................... 62 4.2 Conclusion ...................................................................................................................................... 70 Appendix ............................................................................................................................................... 72 References ............................................................................................................................................. 87 List of Tables Table 1 information obtained from a datasheet produced by The Centre for Agriculture and Bioscience International. It shows the areas in Oceania in which Phytophthora cinnamomi is established...................................................................................................................................... ......... 7 Table 2 the p-values between days for soluble phenolics content for leaves treated with 4.1mM jasmonic acid...................................................................................................................................... ... 35 Table 3 the p-values between days for soluble phenolics content for leaves treated with 21.9mM jasmonic acid...................................................................................................................................... ... 36 Table 4 the p-values between days for esterified phenolics content for leaves treated with 4.1mM jasmonic acid................................................................................................................................. ........ 37 Table 5 the p-values between days for esterified phenolics content for leaves treated with 20.5 mM jasmonic acid.................................................................................................................................. ....... 38 Table 6 the p-values between days for the total phenolic content shows the p-values between days for the total phenolic content for leaves treated with 4.1mM jasmonic acid..................................... ......... 39 Table 7 the p-values between days for the total phenolic content for leaves treated with 20.5 mM jasmonic acid..................................................................................................................................... .... 40 Table 8 the p-values between days for the tannin content for leaves treated with 4.1mM jasmonic acid......................................................................................................................................... ............... 41 Table 9 the p-values between days for the tannin content for leaves treated with 21.9mM jasmonic acid......................................................................................................................................... ............... 42 Table 10 the p-values between days for the lignin content (absorbance units) for leaves treated with 4.1mM jasmonic acid......................................................................................................................... ... 43 Table 11 the p-values between days for the lignin content (absorbance units) for leaves treated with 20.5mM jasmonic acid......................................................................................................................... 44 Table 12 the p-values between days for the soluble phenolics for leaves treated with 4.4mM salicylic acid...................................................................................................................................................