THE DISTRIBUTION OF FR~E AMINO ACIDS IN DIASTELLA SALISB. , LEUCOSPERHUH R. BR. AND SOME OTHER MEMBERS OF THE PROTEACEAE by Leslie Ward Powrie Thesis sub•itted in fulfil1ent of the require1ents of the degree UniversityMagister of Scienteae Cape Town at the University of Cape Town. Cape Town May 1986 Pro1oter : Prof. J. N. Eloff --University of Cape Town has been given right to reproduce this thesis in whole ~ or in part. Copyright Is held by the author. ·.. ~· The copyright of this thesis vests in the author. No quotation from it or information derived from it is to be published without full acknowledgement of the source. The thesis is to be used for private study or non- commercial research purposes only. Published by the University of Cape Town (UCT) in terms of the non-exclusive license granted to UCT by the author. University of Cape Town THE DISTRieUTION OF FREE AMINO ACIDS IN DIASTELLA SALISB., LEUCOSPERNVW R.BR. AND SOME OTHER MEMBERS OF THE PROTEACEAE " It is untenable ••• to view secondary plant 1etabolites as plant 'garbage cans' designed for 'containerizing' nonfunctional 1olecules." Rosenthal (1982) CONTENTS 1. INTRODUCTIOII .•.....•...••...............•...•..•....•••.•....•••.••....•..•••..••.••••.••••.•••••...•••••..•• 1 1.1 BackgrOII'MI I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I • I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I t I I I I I I I I I I I I I 1 1. 2 Prob 1et statetent ··································································~······················ 1 2. LITERATtiE REVIEW •••••••• • •••••••••••••••••••••••••••••••••••••••••• -................. •.••••••••••••••••••••••• 3 2.1 Free Alino Acids - biological roles •...•.......•....•...•....•..•.....•..••...••..••.•.•••..••••.......••• 3 2.2 Suitable characters for use as chetotaxon01ic .arkers ............•...••..•••.••....••.•••.•...••••..•..••• 5 2.2.1 Free ilino acids as chetotaxon01ic .arkers ....•...•.......•....•...•...••.•••.....•..•••.......••....• 6 2.3 Chelotaxon01ic analyses using free a~ino acids •.......••.....••••...•.......•..••......•...••.......••••.• 8 2.3.1 The use of ruerical aids in taxonOIY ................................................................. 9 2.4 Cheiotaxon01ic identification of the parents of a hybrid .................................................. 10 2.5 The taxonOIY of the Proteaceae ...•...•...•...••...•...•..•.....•..••........•.............•....••......•.. 11 2.5.1 Chelical 110rk on the fa~ily Proteaceae .......•.....•.•••...••.••.........•.....•...••...•......•••.... 13 2.6 Sole notes on the extraction of free a11ino acids •....•.••••.......•...•••..•...•••.••.•....•...•........•. 14 3. IIATERIALS AI) IETIIJOS ...................•...•..••...••..•....•...••........•........•.........•...•.••.....•. 15 3.1 Plant .aterial ······································································~····················· 15 3.1.1 Dii1Stt11i Salisb. ...........•.........•.•........•...••....•..............••.......................... 15 3.1.2 Leuct~SP~,.. R. Br. ...••...•...••..•.........••.••.....•.•....••.••....••..•...••....•••.........••••. 16 3.1.3 Hybrids ..•....•....••...•..••....•••••••..••••••••......•••.....•..••...•••..••..••......•..........•. 19 3.1.4 Indigenous species of the Proteaceae ..••....••.••.••...••..•••...•...•••..•....••...•••...•••..•....•. 19 3.1.5 Exot;c species of the Proteaceae •• •• •• •• •• • •• •• •• • •• • •• •• • •• • •• •• • • •• • • • •• •• •• •........... •.• •• • •• • • •• • • 20 3. 2 Method deve1 op~~ent ..................••......•••.........•...•...••...••................................... 21 3.2.1 Standardisation of extraction procedure .•............••...•..•...•••.••.•...•.•.•••.•.••••.•.•••••..•. 21 3.2.1.1 Post-harvest, Pre-extraction conditions ........................................................... 22 3.2.2 ProbleiS enceu~tered with a brown precipitate in the extract ......................•..........•........ 29 Selection of suitable plant organs for analysis 30 3.2.3 ·······························~······················· 3.3 Extraction procedure .••....•...•••....•.......•.•..•....••.•••......•.••••...••••.•••..••••••••••••..••... 32 3.3.1 Maceration of tissue .................................................................................. 34 3.3.2 Solubilisation of the free a~ino acid fraction ........................................................ 34 3.3.3 Dry laSS detel'lination ...............•................................................................ 35 3.3.4 Separation of aqueous and non-aqueous phases .......................................................... 35 3.3.5 Cation exchange and final preparation of extract and its storage .....................................• 35 3.4 Analysis of free a1ino acids in the extract ............................................................... 37 3.4.1 Paper chroaatography ..........................................................................•....... 37 3.4.2 Autoaatic a~ino acid analysis (AM) ··························································~········ 37 3.4.2.1 Details of the analysis .................•.........•.....................•......................... 37 3.4.2.2 Separation of a~ino acids .................•....................•................................•. 38 3.4.2.3 DetecUon and reporting of eluted CQIIICUICis .............................................•......... 40 3.4.2.4 Presentation of AM data .......................................................................... 40 3.5 Statistical reliability ....................................................................•.............. 45 3.6 Cluster analysis of data .................................................................................. 45 3.6.1 Indices of si1ilarity used in vegetation studies .................................•.•.......••........ 47 3.6.2 Dissi1ilarity index used by Spencer .................................................•................ 47 3.6.3 Cluster analysis using correlation coefficient .....................................................•. 49 3.6.4 ll»servations on the application of cluster analysis .................................................. 49 4. RESli.TS .••..•.....•....••......•.•..•.....•...••...••..••..•.•...•.•.........•...••..•••.••••..•••.•••••...•• 51 4.1 Free a~ino acids in Diaste11i ...............................................•............................. 51 4.2 Free a1ino acids in Leuc(J5fle,.. species ............................................................•..... 51 4.3 Free a1ino acids in the fa1ily Proteaceae ................................................................. 51 4.3.1 Cluster analysis of the data .....................•...................••............................... 54 4.4 Free a~ino acids in hybrids ...............................................................•............... 59 5. DISCUSSIII ............................................................•..........••........•................. 62 5.1 Free •ino acids as chelotaxonalic urkers in the f•HJ Proteaceae ....................................... 62 5.2 Interpretation of data .......•...••.................................•.............•....................... 62 5.3 Colparison with pamlished Data ......•••.....•..........................•........................•........• 63 5.4 Analysis of the data ...............•.........................................................••........... 63 5.5 Statistical reliability ................................................................•.................. 64 5.6 The F11dion of free •ino acids in the Proteaceae ..................................•............•........ 64 5.7 Conclusion ........................•............................•......................................•..• 65 5.8 Future work ..................................•.................................•.............•............ 67 ...•....•••.....•......•.•...........•.•....•......••.............•••............••••..................... 68 ~s .................................................................................................. 10 .........•.........•.........................•..........................•.••............••............. 71 APPENDIX A IN. specifications •••••••••••••••••••••••••••••••..••••• ~••••••••••••.•••••••••••• -...... ••• •• • • • • • • • • • • 74 APPENDIX 8 Cluster analysis progr• listings ••..........................•.......•.....•..........•...•.......... 77 APPENDIX C Printouts of_cluster nlyses ........................................................................ 86 93 APPENDIX D Abbreviations ···································~···················································· 1. INTRODUCTION 1.1 Background Diastella Salisb. is a s1all Proteaceous genus ende1ic in a very s1all distribution range in the extre1e South- western corner of the Cape. Diastella co1prises seven species. Rourke (1976) recently revised Diastella for the account of the Proteaceae being prepared for the Flora of Southern Africa. In this revision he reports that 18th ; century classifications placed most of the known species of Diastella in either Protea or Leucadendron. In 1809 Salisbury founded Diastella. Brown rejected this classification in 1810 and for1ed a clu1sy and confusing arrangement by placing these species in Ni1etes Salisb. Sect II Ni1etes spuriae R. Br.. In 1911 Phillips reinstated Diastella. Hall and Veldhuis (1985) list D. buekii as 'endangered', D. •rrtifolii as 'critically