Charles Roger Slack
(1937–2016)
PhD FRSNZ FRS
Roger received a Goldacre Award from the Australian Society of Plant Physiologists in 1970, shared the Charles F Kettering award from the American Society of Plant Physiologists in 1980 and the Rank Prize for Nutrition in 1981. He was elected Fellow of the Royal Society of New Zealand in 1983 and of the Royal Society of London in 1989. In 2007 the New Zealand Society of Plant Biologists renamed their annual award for outstanding physiologists the Roger Slack Award.
What had he done to deserve these accolades?
After graduating with BSc (Hons) from The School of Agricultural Science at The University of Nottingham in 1958, Roger undertook a short course in biochemistry at University College, London, before returning to Nottingham and gaining a PhD. In 1962 he was recruited by the David North Plant Research Centre in Brisbane, Queensland, which was funded by The Colonial Sugar Refining Co. (CSR), and began working on the biochemistry of sucrose accumulation by sugar cane.
When completing current work in 1965, he and colleague, Hal Hatch, decided to follow up on intriguing reports from sugar cane researchers in Hawaii suggesting that sugar cane might assimilate carbon dioxide by a mechanism different from the photosynthetic pathway established for other plants. Hal and Roger quickly confirmed that C4 acids, oxaloacetic, malic and aspartic acids, were the first labelled products of 14CO2 fixation by sugar cane leaves and that typical intermediates of the classic photosynthetic carbon reduction cycle became labelled only later. In pulse-chase experiments the C-4 carboxyl of the acids gave rise to the C-1 of 3-phosphoglyceric acid, an early intermediate in the established photosynthetic cycle. The resulting paper published in the Biochemical Journal in 1966 has logged 682 citations to date indicating its importance in plant biochemistry/physiology.
Clearly this phenomenon warranted further study. Hatch and Slack went on to identify phosoenolpyruvate (PEP) carboxylase as the crucial enzyme in the sugar cane photosynthesis and identified a number of novel enzymatic reactions, particularly the fastidious pyruvate orthophosphate dikinase reaction, required for the reduction of 14CO2 in this new process. Suddenly, it seemed, researchers in photosynthesis were all agog with PEP-carboxylase, malate dehydrogenase and aspartate aminotransferase rather than ribulose diphosphate carboxylase, and the new model was frequently referred to in publications as the Hatch-Slack pathway, though never by Hal and Roger. Not unexpectedly, there was a wall of scepticism to overcome, but within less than four years they had proposed a chemistry of C-4 photosynthesis that stimulated a virtual frenzy of international research fine tuning their proposal into the currently accepted model.
Plants with C-4 photosynthesis are characterised by high growth rates, low CO2 compensation points, high water use efficiency and, crucially, leaf anatomy with specialised mesophyll and bundle sheath cells. Carbon dioxide is initially captured by PEP carboxylase in mesophyll cells and the resulting C4 acids transported into bundle sheath cells where CO2 is released then re-fixed in the classic photosynthesis cycle. Three carbon acids are returned to mesophyll cells and converted to PEP to complete the C-4 cycle. Hence, by 1970 Hal, Roger and colleagues had concluded that the C-4 addendum to the classic photosynthetic cycle ensured a high CO2 / low O2 environment for RuDP-carboxylase activity in bundle sheath cells allowing for a more efficient net CO2 assimilation. Such a CO2 “pump” would explain the low CO2 compensation point and high growth rate characteristic of plants possessing the C-4 pathway.
In the late 1960s Roger and Hal were directed by CSR management to curtail work on photosynthesis and concentrate on more urgent problems of sugar production. Of some interest, Coca Cola had complained that sugar from Townsville contained a substance that caused a haze to appear in bottles of their product when displayed backlit. The culprit was identified as dextran which was produced by bacteria that infected juice exuding from cane stalks damaged in the burning practised to remove vermin from the crop and to facilitate harvesting. Roger began a search for a dextranase to hopefully solve the problem, which was however, solved by not burning the cane field prior to harvest. Not to be deterred, he persisted with producing a dextranase which could be added to toothpaste to reduce dental plaque formation.
By 1970 Roger was in Palmerston North, New Zealand, recruited to a temporary position created to celebrate the opening of the new controlled environment facilities at Plant Physiology Division (PPD) of the NZ Department of Scientific and Industrial Research (DSIR). The brief given to biochemists at PPD was to discover why some plants are chilling-sensitive, as the director of the institution had a vision of most of the pastoral North Island clothed in high yielding tropical and sub-tropical (i.e. C-4) forage grasses, but realised that the desirable species performed poorly at low (non-freezing) temperatures. Overcoming this chilling-sensitivity could result in a very significant increase in the production of animal fodder at a time when the climate was optimal for growth. By contrast, the current Mediterranean species in use became dormant under the same conditions.
A consensus was developing in the early 1970s that the lipids of cell membranes “sensed’ chilling temperatures by undergoing phase transitions which disrupted normal membrane function and led in time to cell death. Thermal properties of the membrane lipids and their fluidity would be determined by their fatty acid compositions, but how unsaturated fatty acid synthesis was controlled was unknown. Roger was persuaded by Grattan Roughan to join him in following up on an odd discovery concerning plant lipid metabolism that he had published in 1970 but which had been largely ignored. Going against conventional wisdom those results had suggested that fatty acids synthesised de novo within chloroplasts of pumpkin leaves were exported to the endoplasmic reticulum, incorporated into phosphatidylcholine, desaturated there and returned to the chloroplasts for assembly particularly of the major chloroplast membrane lipids. This was not well received by the plant lipid community.
With typical determination and ingenuity Roger, working with developing maize leaves, confirmed and greatly extended those earlier results and in 1975 published a definitive paper in the Biochemical Journal that was the first in a series of quality reports completely changing the thinking of plant lipid researchers, well some of them anyway. There could now be no doubt that fatty acid synthesis and desaturation in maize and pumpkin leaves required the cooperation of chloroplasts and cytoplasmic endoplasmic reticulum, and that oleate was desaturated only after being incorporated into glycerolipids. After working with maize and spinach leaves Roger concentrated on oleate desaturation and lipid accumulation in oil seeds while Grattan began a detailed study of the capabilities and limitations of lipid synthesis by isolated chloroplasts. They were ably assisted in this work by John Browse, Ross Holland and Sue Gardiner, in particular. The complementary studies resulted in 1980 of the presentation of a scheme for leaf glycerolipid synthesis that had one set of molecular species (now called prokaryotic) synthesised entirely within chloroplasts while synthesis of a second set of molecular species (eukaryotic) required cooperation of the different cell compartments. This 2- pathway model neatly explains a number of otherwise puzzling properties of plant lipids and appears to have survived the test of time in spite of initially coming up against strong opposition.
Roger was an exceptional hands-on experimentalist, sharp as a tack and a most agreeable colleague to work alongside. He had co-authored two authoritative reviews on plant biochemistry in Annual Reviews in Plant Physiology (1970 and 1982) in totally different fields yet behaved as if unaware of his scientific reputation. Both the C-4 pathway of photosynthesis and the 2-pathways of lipid synthesis in plants are standard fare in modern textbooks where due credit is given. It could be argued that the original contentious discoveries only became respectable following Roger’s involvement.
Grattan Roughan
Formerly Plant Physiology Division, DSIR, Palmerston North and Division of Horticulture and Processing, DSIR, Auckland
After 1980 Roger felt the need to apply himself to more practical research and turned his impressive talents to improving the processing quality of malting barley varieties bred for the New Zealand environment. He became aware that the New Zealand cereal breeders lacked laboratory support for selecting breeders’ barley lines on the basis of their potential malting quality. With barley for malting, his approach was to mimic the industrial-scale malting process in the laboratory by producing malts from large numbers of grain samples, and to then subject these malts to a range of analyses designed to predict their suitability for malting and brewing. The initial work was largely labour-intensive but the micro-malting and malt analyses were streamlined to cope with the sample numbers. This work rapidly evolved to deal with both the screening of early generation lines and the evaluation of later generation material. In addition to the standard grain and malt tests, Roger also took an interest in novel grain attributes including grain and wort β-glucan levels, and the identification and selection of proanthocyanidin-free barleys. During this period, Roger also took an interest in wheat proteins implicated with baking quality and he used polyacrylamide gel electrophoresis to separate wheat glutenin and gliadin proteins for the purpose of identifying varieties and establishing their purity, and screening breeders’ lines as potential parents.
Roger’s clarity of thinking and leadership was evident with this applied work, and together with his close DSIR colleagues Martin McEwan, Roger Haslemore, Cecil Tunnicliffe and others, he encouraged strong collaborative links with Derek Smith and the barley breeders of the Plant Breeding Institute, Cambridge, UK, and with John Smart from the Canterbury (NZ) Malting Company. These links brought the team at Palmerston North much closer to like-minded breeders, chemists and biochemists in the UK and the New Zealand malting industry.
In the early 1990s, Roger and his colleagues became part of the newly formed Crown Research Institute of Crop & Food Research and Roger’s focus changed yet again as he decided to take a more active role in breeding high quality malting barley varieties. This included making crosses from parents selected from the laboratory testing and using glasshouses and controlled environment rooms in the Climate Laboratory at Palmerston North to accelerate the small-scale production of early and middle generation lines. From the mid 1990s through to his retirement in 2000, he distanced himself somewhat from the laboratory testing and concentrated on becoming a full-time barley breeder which included all of the physical work involved with planning, sowing, and harvesting of trials plus the labour-intensive work of evaluating agronomic and disease attributes during their growth cycles.
Roger Haslemore
Formerly of Plant Physiology Division, DSIR and The NZ Institute for Crop and Food Research Ltd, Palmerston North
Roger was very concerned about practical, applied outputs at this stage of his career, and thought that wrapping up his biochemical knowledge and understanding within a new barley cultivar was a logical progression. Unfortunately, he had not finally achieved a commercial release at the time of his retirement, and very soon afterwards this programme was closed in the face of strong private company competition and modest New Zealand industry demand. However, when Crop and Food Research closed the programme, the germplasm was made available to some of these private breeding operations, and several of his advanced lines did find their way into pedigrees which later were commercially released. His strong scientific focus upon the underlying biochemical characterisation of quality is also a lasting legacy which is still applied within all crop breeding programmes. It is a measure of Roger’s desire to reach useful and worthy scientific goals that he often observed that he should have taken up breeding some years sooner than he did.
Bill Griffin
Formerly of Crop Research Division, DSIR and The NZ Institute for Crop and Food Research Ltd, Palmerston North
Charles Roger Slack was born at Ashton under Lyne, outer Manchester, on 22 April 1937, the first and only child of Albert and Eva Slack. He recalled several bombs falling perilously close to where he had lived during the war years and being taken by older friends to comb through the bomb craters for shrapnel. His father was always a very keen gardener and during the war on Sunday mornings he would walk his son 3 km into the outskirts of Hyde to visit a friend working in his greenhouses. Immediately after the war his dad built a large glass house on very fertile land on the banks of the Tame river where the young Roger learned how to grow tomatoes, propagate chrysanthemums and to debud them. Tragically when Roger was just 11 years old his father died and he was raised thereafter by his mother alone. He attended grammar school at Audenshaw, Manchester, and as a top-stream student progressed to the 6th form at an early age. While at school he had decided to study agriculture and horticulture, an odd choice apparently for someone from the industrial north but perhaps not for someone who already had horticultural experience, and his application to The School of Agricultural Science at The University of Nottingham was accepted with the proviso that he first spend a year working on a farm. While he was studying at the Sutton Bonnington campus he met Pam Shaw, who had come from Aberystwyth to Nottingham to enrol on a PhD course. After Roger had flown to Brisbane for his new appointment Pam followed by sea as a “10 pound Pom” - her words - arriving in February 1963. They were married in March and Andrew was born in late December. Kathy followed in 1966. Setting up a new home and dealing with young children didn’t leave much time for extra-curricular activities but Roger did acquire a sailing dinghy which he regularly launched on Morton Bay. According to his crew he was a pretty demanding and unforgiving skipper. He honed his carpentry skills in Palmerston North, by building an Optimus class sailing dinghy for Andrew in his garage. Roger wrote his papers at home in the evenings and was adamant that his time in the lab was to be spent experimenting.
With children growing up, Pam and Roger found New Zealand to be eminently suitable for exploration and covered the country with annual camping trips from mid December to mid January. Both were keen trampers and completed several of the well-known South Island scenic walks. Roger developed a passion for fly fishing at which he eventually became successful enough to endure trying conditions to catch his bag of fish. A good family man, he introduced his children to hiking and exploration, activities that they continue to pursue. He was a skilful woodworker and home handyman and inherited an abiding interest in gardening and horticulture from his father. He made a heroic effort to improve the sand-stabilising cover at the mouth of the Manawatu River and was forever tinkering with other plant species. After retiring, he remained in contact with a malting company in Albury, NSW and inspected trials at Howlong. Roger spent some of his time in retirement researching his ancestry for the benefit of his offspring and read widely on a number of topics. A hip replacement in 1998 was very successful and restored his previous ability to pursue his favourite outdoor activities but his mobility and health deteriorated following replacement of the other hip in 2005. He had a mild heart attack in 2009 and was diagnosed with congestive heart failure and sub-optimal kidney function. Rejecting the chance to undergo dialysis, he eventually died from kidney failure.
Pam Slack
Roger’s most enduring extra-curricular activity, which he shared with Pam, was the study of birds in which had been a lifelong interest. He and Pam were a formidable team at spotting birds and they travelled extensively in New Zealand, Australia and the United Kingdom in search of birds. He was a stalwart of the Ornithological Society of New Zealand (now Birds New Zealand) and with a group from like-minded stalwarts he once, somewhat reluctantly, spent a day far out at sea hoping to record a sighting of the seriously endangered stormy petrel. Arctic waders were a speciality for Roger and he liked to reminisce about the golden plovers and curlews breeding on the uplands of his native north of England, and the knots and tattlers seen on the Cairns foreshore in Queensland. These shorebirds breed in the arctic and high latitudes of the northern hemisphere and migrate to estuaries in the southern hemisphere for the austral summer. Bar-tailed Godwits and Red Knots visit New Zealand in internationally significant numbers every year and about eight other species are regular annual visitors in small numbers while many more species have been recorded as rare vagrants. Following his retirement Roger made regular fortnightly visits to the Manawatu River Estuary at Foxton to study arctic waders. His scientific bent came to the fore here. There was the careful observation and precise counting, the recording in his diary of bird numbers and details of leg bands, and the sending of results to the authorities compiling nation-wide counts for publication. And of course he always had theories (= ideas) to explain interesting observations. There were moments of great excitement at Foxton. For example, the sighting of two rare (for New Zealand) arctic waders, Greenshank and Marsh Sandpiper (both Tringa species), at the same time on 13 January 2013. This sighting brought a bright gleam of satisfaction to Roger's eye, something that his fellow birding addicts will identify with.
Our native New Zealand breeding waders were not neglected. Wrybill numbers at Manawatu Estuary were carefully monitored and visits were made to gravel areas of the Manawatu River to observe the activities of dotterel species. Roger had the scientist's eye for important detail. He could readily distinguish clutches of dotterel eggs with their grey-brown colour amongst the grey rounded stones of the riverbed, something that others birders often struggled to do. He was a staunch supporter of the Pukokoro Miranda Naturalist's Trust located on the coast of the Firth of Thames. The Trust is the major centre for the study of wading birds in New Zealand and he visited their mudflats and wetlands whenever he could. He was also a member of Forest and Bird and had a keen interest in the conservation and recovery of endangered native birds. Roger and Pam visited many sanctuaries where rare bird populations are being actively managed. He retained an interest in British birds all his life and was a member of the Royal Society for the Protection of Birds (UK). Those of us who went on birding trips with Roger will remember the many hours spent in his genial company and the wonderful hospitality he and Pam always extended. An abiding memory is of Roger at the estuary pushing forth into the near gale westerly with sand stinging his feet but determined to find the rare wader that was always going to be on the next shoreline.
Lindsay Davies
Formerly of Plant Physiology Division, DSIR, Palmerston North
Bibliography
We have been unable to find Roger’s personal list of his publications and are forced to conclude he hadn’t compiled one. The following bibliography has been researched by Ian Brooking and John Christeller formerly of Plant Physiology Division, DSIR, Palmerston North,and is presented here as his publications with 50 or more citations followed by the remainder in chronological order.
Roger’s most cited publications in Google Scholar as of December 2016
Hatch, M. D. and C. R. Slack (1966). Photosynthesis by sugar-cane leaves: a new carboxylation reaction and the pathway of sugar formation. Biochemical Journal 101(1): 103-111. [GS cites: 683]
Hatch, M. D. and C. R. Slack (1970). Photosynthetic CO2-fixation pathways. Annual Review of Plant Physiology 21: 141-162. [GS cites: 540]
Roughan, P. G. and C. R. Slack (1982). Cellular organization of glycerolipid metabolism. Annual Review of Plant Physiology and Plant Molecular Biology 33: 97-132. [GS cites: 505]
Hatch, M. D., C. R. Slack and H. S. Johnson (1967). Further studies on a new pathway of photosynthetic carbon dioxide fixation in sugar-cane and its occurrence in other plant species. Biochemical Journal 102(2): 417-422. [GS cites: 259]
Slack, C. R. and M. D. Hatch (1967). Comparative studies on the activity of carboxylases and other enzymes in relation to the new pathway of photosynthetic carbon dioxide fixation in tropical grasses. Biochemical Journal 103(3): 660-665. [GS cites: 240]
Hatch, M. D. and C. R. Slack (1968). A new enzyme for the interconversion of pyruvate and phosphopyruvate and its role in the C4 dicarboxylic acid pathway of photosynthesis. Biochemical Journal 106(1): 141-146. [GS cites: 234]
Slack, C. R., M. D. Hatch and D. J. Goodchild (1969). Distribution of enzymes in mesophyll and parenchyma-sheath chloroplasts of maize leaves in relation to the C4-dicarboxylic acid pathway of photosynthesis. Biochemical Journal 114(3): 489-498. [GS cites: 222]
Roughan, P. G., R. Holland and C. R. Slack (1980). The role of chloroplasts and microsomal fractions in polar-lipid synthesis from [1-14C] acetate by cell-free preparations from spinach (Spinacia oleracea) leaves. Biochemical Journal 188(1): 17-24. [GS cites: 153]
Hatch, M. D., C. R. Slack and T. A. Bull (1969). Light-induced changes in the content of some enzymes of the C4-dicarboxylic acid pathway of photosynthesis and its effect on other characteristics of photosynthesis. Phytochemistry 8(4): 697-706. [GS cites: 136]
Hatch, M. D. and C. R. Slack (1969). Studies on the mechanism of activation and inactivation of pyruvate, phosphate dikinase. A possible regulatory role for the enzyme in the C4 dicarboxylic acid pathway of photosynthesis. Biochemical Journal 112(5): 549-558. [GS cites: 131]
Roughan, P. G., R. Holland and C. R. Slack (1979). On the control of long-chain-fatty acid synthesis in isolated intact spinach (Spinacia oleracea) chloroplasts. Biochemical Journal 184(2): 193-202. [GS cites: 125]
Hatch, M. D. and C. R. Slack (1969). NADP-specific malate dehydrogenase and glycerate kinase in leaves and evidence for their location in chloroplasts. Biochemical and Biophysical Research Communications 34(5): 589-593. [GS cites: 122]
Browse, J., N. Warwick, C. R. Somerville and C. R. Slack (1986). Fluxes through the prokaryotic and eukaryotic pathways of lipid synthesis in the '16: 3' plant Arabidopsis thaliana. Biochemical Journal 235(1): 25-31. [GS cites: 115]
Slack, C. R., P. G. Roughan and J. Terpstra (1976). Some properties of a microsomal oleate desaturase from leaves. Biochemical Journal 155(1): 71-80. [GS cites: 112]
Campbell, W. P., C. W. Wrigley, P. J. Cressey and C. R. Slack (1987). Statistical correlations between quality attributes and grain-protein composition for 71 hexaploid wheats used as breeding parents. Cereal Chemistry 64(5): 293-299. [GS cites: 110]
Slack, C. R. and P. G. Roughan (1975). The kinetics of incorporation in vivo of [14C] acetate and [14C] carbon dioxide into the fatty acids of glycerolipids in developing leaves. Biochemical Journal 152(2): 217-228. [GS cites: 101]
Roughan, G. and R. Slack (1984). Glycerolipid synthesis in leaves. Trends in Biochemical Sciences 9(9): 383-386. [GS cites: 100]
Slack, C. R., P. G. Roughan and N. Balasingham (1978). Labelling of glycerolipids in the cotyledons of developing oilseeds by [1-14C] acetate and [2-3H] glycerol. Biochemical Journal 170(2): 421-433. [GS cites: 100]
Slack, C. R., P. G. Roughan and N. Balasingham (1977). Labelling studies in vivo on the metabolism of the acyl and glycerol moieties of the glycerolipids in the developing maize leaf. Biochemical Journal 162(2): 289-296. [GS cites: 95]
Slack, C. R., P. G. Roughan, J. A. Browse and S. E. Gardiner (1985). Some properties of cholinephosphotransferase from developing safflower cotyledons. Biochimica et Biophysica Acta 833(3): 438-448. [GS cites: 94]
Everson, R. G. and C. R. Slack (1968). Distribution of carbonic anhydrase in relation to the C 4 pathway of photosynthesis. Phytochemistry 7(4): 581-584. [GS cites: 94]
Roughan, P. G., J. B. Mudd, T. T. McManus and C. R. Slack (1979). Linoleate and α-linolenate synthesis by isolated spinach (Spinacia oleracea) chloroplasts. Biochemical Journal 184(3): 571-574. [GS cites: 90]
Slack, C. R., P. G. Roughan and J. Browse (1979). Evidence for an oleoyl phosphatidylcholine desaturase in microsomal preparations from cotyledons of safflower (Carthamus tinctorius) seed. Biochemical Journal 179(3): 649-656. [GS cites: 90]
Roughan, P. G., C. R. Slack and R. Holland (1978). Generation of phospholipid artefacts during extraction of developing soybean seeds with methanolic solvents. Lipids 13(7): 497-503. [GS cites: 80]
Taylor, A. O., C. R. Slack and H. G. McPherson (1974). Plants under climatic stress VI. Chilling and light effects on photosynthetic enzymes of sorghum and maize. Plant Physiology 54(5): 696-701. [GS cites: 80]
Andrews, T. J., H. S. Johnson, C. R. Slack and M. D. Hatch (1971). Malic enzyme and aminotransferases in relation to 3-phosphoglycerate formation in plants with the C4-dicarboxylic acid pathway of photosynthesis. Phytochemistry 10(9): 2005-2013. [GS cites: 74]
Roughan, P. G. and C. R. Slack (1977). Long-chain acyl-coenzyme A synthetase activity of spinach chloroplasts is concentrated in the envelope. Biochemical Journal 162(2): 457-459. [GS cites: 72]
Slack, C. R. (1968). The photoactivation of a phosphopyruvate synthase in leaves of Amaranthus palmeri. Biochemical and Biophysical Research Communications 30(5): 483-488. [GS cites: 68]
Slack, C. R., W. S. Bertaud, B. D. Shaw, R. Holland, J. Browse and H. Wright (1980). Some studies on the composition and surface properties of oil bodies from the seed cotyledons of safflower (Carthamus tinctorius) and linseed (Linum ustatissimum). Biochemical Journal 190(3): 551-561. [GS cites: 67]
Roughan, P. G., R. Holland, C. R. Slack and J. B. Mudd (1979). Acetate is the preferred substrate for long-chain fatty acid synthesis in isolated spinach chloroplasts. Biochemical Journal 184(3): 565-569. [GS cites: 66]
Graham, D., M. D. Hatch, C. R. Slack and R. M. Smillie (1970). Light-induced formation of enzymes of the C4-dicarboxylic acid pathway of photosynthesis in detached leaves. Phytochemistry 9(3): 521-532. [GS cites: 65]
Slack, C. R., P. G. Roughan and H. C. M. Bassett (1974). Selective inhibition of mesophyll chloroplast development in some C4-pathway species by low night temperature. Planta 118(1): 57-73. [GS cites: 63]
Slack, C. R., L. C. Campbell, J. A. Browse and P. G. Roughan (1983). Some evidence for the reversibility of the cholinephosphotransferasecatalysed reaction in developing linseed cotyledons in vivo. Biochimica et Biophysica Acta 754(1): 10-20. [GS cites: 54]
Roughan, P. G., C. R. Slack and R. Holland (1976). High rates of [1-14C] acetate incorporation into the lipid of isolated spinach chloroplasts. Biochemical Journal 158(3): 593-601. [GS cites: 51]
Lowe, J. and C. R. Slack (1971). Inhibition of maize leaf phosphopyruvate carboxylase by oxaloacetate. Biochimica et Biophysica Acta 235(1): 207-209. [GS cites: 50]
Remainder of publications, chronologically
Slack, C. R. and W. J. Whittington (1964). The role of boron in plant growth III. The effects of differentiation and deficiency on radicle metabolism. Journal of Experimental Botany 15(45): 495-514.
Slack, C. R. (1965). The physiology of sugar-cane VIII. Diurnal fluctuations in the activity of soluble invertase in elongating internodes. Australian Journal of Biological Sciences 18(4): 781-788.
Slack, C. R. (1966). Inhibition of UDP glucose: D-fructose 2-glucosyltransferase from sugar cane stem tissue by phenol oxidation products. Phytochemistry 5(3): 397-403.
Hatch, M. D. and C. R. Slack (1967). The participation of phosphoenolypyruvate synthetase in photosynthetic CO2 fixation of tropical grasses. Archives of Biochemistry and Biophysics 120(1): 224-225.
Slack, C. R. (1969). Localization of certain photosynthetic enzymes in mesophyll and parenchyma sheath chloroplasts of maize and Amaranthus palmeri. Phytochemistry 8(8): 1387-1391.
Roughan, P. G. and C. R. Slack (1973). Simple methods for routine screening and quantitative estimation of oxalate content of tropical grasses. Journal of the Science of Food and Agriculture 24(7): 803-811.
Roughan, P. G. and C. R. Slack (1974). Glycerolipid involvement in biosynthesis of polyunsaturated fatty-acids in plants. Chemistry in New Zealand 38(4): 117-117.
Taylor, A. O., C. R. Slack and H. G. McPherson (1974). Effect of “low” temperatures on the levels and activity of some C4-pathway enzymes. Bulletin, The Royal Society of New Zealand(12): 519-524.
Slack, C. R., P. G. Roughan and H. C. M. Bassett (1974). Selective inhibition of mesophyll chloroplast development in some C4-pathway species by low night temperatures. Bulletin, The Royal Society of New Zealand(12): 499-504.
Roughan, P. G. and C. R. Slack (1976). Is phospholipase D really an enzyme?: A comparison of in situ and in vitro activities. Biochimica et Biophysica Acta 431(1): 86-95.
Forde, B. J., C. R. Slack, P. G. Roughan and H. C. M. Whitehead (1976). Growth of tropical and temperate grasses at Palmerston North: I. Warm-season yields with and without irrigation. New Zealand Journal of Agricultural Research 19(2): 135-142.
Forde, B. J., C. R. Slack, P. G. Roughan, R. M. Haslemore and M. N. McLeod (1976). Growth of tropical and temperate grasses at Palmerston North: II. Total nitrogen, soluble sugar, starch, and in vitro digestibility determinations. New Zealand Journal of Agricultural Research 19(4): 489-498.
Slack, C. R. and P. G. Roughan (1978). Rapid temperature-induced changes in the fatty acid composition of certain lipids in developing linseed and soya-bean cotyledons. Biochemical Journal 170(2): 437-439.
Slack, C. R. and P. G. Roughan (1980). A comparison of the polypeptide and phospholipid composition of oil body and microsomal preparations from safflower and linseed cotyledons. In Biogenesis and Function of Plant Lipids eds. P.Mazliak, P. Benviste, C. Costes and R. Douce.Elsevier/North Holland Biomedical Press: 219-222.
Roughan, P. G. and C. R. Slack (1980). The role of chloroplasts in leaf lipid metabolism and polyunsaturated fatty acid biosynthesis. In Biogenisis and Function of Plant Lipids eds. P.Mazliak, P.Benveniste, C.Costes and R.Douce. Elsevier/North Holland Biomedical Press: 11-18.
Nikolau, B. J., J. C. Hawke and C. R. Slack (1981). Acetyl-coenzyme A carboxylase in maize leaves. Archives of Biochemistry and Biophysics 211(2): 605-612.
Browse, J., P. G. Roughan and C. R. Slack (1981). Light control of fatty acid synthesis and diurnal fluctuations of fatty acid composition in leaves. Biochemical Journal 196(1): 347-354.
Roughan, P. G. and C. R. Slack (1981). Acyl-CoA may be a neglected product in studies of fatty acid synthesis by isolated chloroplasts. FEBS Letters 135(1): 182-186. [WoS cites: 12] [GS cites: 13]
Browse, J. A. and C. R. Slack (1981). Catalase stimulates linoleate desaturase activity in microsomes from developing linseed cotyledons. FEBS Letters 131(1): 111-114.
Haslemore, R. M., C. R. Slack and K. N. Brodrick (1982). Assessment of malting quality of lines from a barley breeding programme. New Zealand Journal of Agricultural Research 25(4): 497-502.
Willemot, C., C. R. Slack, J. Browse and P. G. Roughan (1982). Effect of BASF 13-338, a substituted pyridazinone, on lipid metabolism in leaf tissue of spinach, pea, linseed, and wheat. Plant Physiology 70(1): 78-81.
Gardiner, S. E., P. G. Roughan and C. R. Slack (1982). Manipulating the incorporation of [1-14C] acetate into different leaf glycerolipids in several plant species. Plant Physiology 70(5): 1316-1320.
Clothier, B. E. and C. R. Slack (1982). Preliminary results of trials using potassium carbonate to accelerate lucerne hay drying (II) Palmerston North. Proceedings Agronomy Society of New Zealand 12: 75-77.
Browse, J. and C. R. Slack (1983). The effects of temperature and oxygen on the rates of fatty acid synthesis and oleate desaturation in safflower (Carthamus tinctorius) seed. Biochimica et Biophysica Acta 753(2): 145-152.
Slack, C. R. (1983). Phosphatidylcholine, an intermediate in polyunsaturated triacylglycerol synthesis. Biosynthesis and function of plant lipids. Proceedings of the Sixth Annual Symposium in Botany: 40-54.
Haslemore, R. M., C. G. Tunnicliffe, C. R. Slack and S. Shaw (1985). An automated micro‐malting unit for quality assessment in a barley breeding programme. Journal of the Institute of Brewing 91(2): 101-105.
Sparks, G. A., D. B. MacGibbon, G. D. Coles and C. R. Slack (1985). Identification of New Zealand grown barley cultivars by grain characters. New Zealand Journal of Experimental Agriculture 13(4): 359-367.
Browse, J. and C. R. Slack (1985). Fatty-acid synthesis in plastids from maturing safflower and linseed cotyledons. Planta 166(1): 74-80.
Thompson, G. A., P. G. Roughan, J. A. Browse, C. R. Slack and S. E. Gardiner (1986). Spinach leaves desaturate exogenous [14C] palmitate to hexadecatrienoate evidence that de novo glycerolipid synthesis in chloroplasts can utilize free fatty acids imported from other cellular compartments. Plant Physiology 82(2): 357-362.
Slack, C. R., D. A. Hancock, R. M. Haslemore and C. G. Tunnicliffe (1986). A simplified method for estimating hot water extract using small malt samples. Journal of the Institute of Brewing 92(3): 262-263.
Gardiner, S. E., M. B. Forde and C. R. Slack (1986). Grass cultivar identification by sodium dodecylsulphate polyacrylamide gel electrophoresis. New Zealand Journal of Agricultural Research 29(2): 193-206.
Browse, J., C. R. Somerville and C. R. Slack (1988). Changes in lipid composition during protoplast isolation. Plant Science 56(1): 15-20.
Haslemore, R. M., C. G. Tunnicliffe, M. G. Peipi, and C. R. Slack (1990) Using wort β-glucan levels to aid selection in a barley breeding programme. - Proceedings 21st Convention of the Institute of Brewing (Aust & NZ Section), Auckland, New Zealand. 79-82.
Hatch, M. D. and C. R. Slack (1998) C4 photosynthesis: discovery, resolution, recognition and significance. In: Kung S and Yang S (eds) Discoveries in Plant Biology, Vol 1, World Scientific Publishing, Singapore. 175–196.
Obituary was lodged on website on 3 April 2017.