Bastiaan J. D. Meeuse

Infrared thermography ofArum lily inflorescences

The infrared radiation emitted from the surface of inflorescences of 12 aroid species was monitored with an infrared camera, capable of 0.1°C resolution, and the data were converted to temperature values by means of temperature reference standards. Images representing surface temperatures were obtained forAmorphophallus bulbifer Blume,A. campanulatus Blume,A. forbesii Engl. et Gehrm.,A. rivieri Dur.,Philodendron selloum Koch,Monstera deliciosa Liebm.,Dracunculus vulgaris Schott,Arum italicum Mill.,A. dioscoridis Sibth.,A. creticum Boiss et Heldr.,Caladium sp., andRemusatia vivipara Schott. These images were different among species with respect to temperature, duration of detectable heat development, and organ type (male and female flowers, spathe and appendix) found to be thermogenic. All these species, however, exhibited three common characteristics: 1) production of heat by the male flowers; 2) pollen-shedding immediately after heat production had ceased; and 3) when male flowers were some distance away from female flowers along the spadix, heat was not detected in female flowers. Heat emission was associated with the alternative, cyanide-insensitive pathway that was fully operative.

X-ray diffraction of algal starches

Abstract The starches of a number of green and red algae were examined by X-ray diffraction. Some showed the X-ray spectrum characteristic of cereal starches, others that characteristic of tuber starches. The former type was not observed in red algae. In many cases in which neither of these spectra was obtained the diagrams generally showed only one, more or less well defined line, always at 4.51 A; they probably represent a new type of starch X-ray spectrum. In a few cases, only a diffuse ring in the 4–6-A region could be obtained, although a true starch was present. In some cases, spectra intermediate between the new type and that of the tuber starches were observed. The observations have been discussed.

A note on the amylolytic breakdown of some raw algal starches

SummaryWith the aid of 5 different amylases (bacterial a.,Cryptochiton a., malt a., pancreatic a. and salivary a.), an optical and biochemical study was made of the amylolytic breakdown of 8 raw algal starches. The latter were obtained from the red algaeConstantinea, Laurencia, Plocamium andRhodymenia and from the green algaeCodium, Hydrodictyon, Spirogyra andUlva. Starches fromCanna, potato, wheat and the mossMnium affine were used as reference materials.Both the moss starch and the algal starches were more easily digestible than the higher plant starches. Depending on the particular amylase used, their order of vulnerability varied somewhat; however,Ulva starch proved to be the most easily digestible material in all cases. Optically, there was no essential difference between the breakdown of native floridean starch and that of native wheat starch; the concentric regularity of the granules as well as the pronounced organization in radial direction were brought out beautifully by the corrosion phenomena. The slight differences in vulnerability noted when florideau starches fromConstantinea, Plocamium andRhodymenia were compared may be attributable to a difference in particle size.

Ultrastructural changes in the appendix of the Sauromatum guttatum inflorescence during anthesis

SummaryThe ultrastructure of the epidermal and sub-epidermal cells of the appendix of the Sauromatum guttatum inflorescence reveals developmental changes during anthesis. These changes precede, and probably make possible, heat and odor production. Two days before D-day (the day of heat production and inflorescence-opening) the mitochondria of the epidermis divide; apparent division of the amyloplasts was observed at the same time. The presence of lipid bodies and peroxisomes in the epidermis was clearly evident. On D-day, the epidermis becomes a continuous layer in which the cell walls separating two adjacent cells disappear. At the same time, in the sub-epidermal cells, the mitochondria and the amyloplasts undergo division. The mitochondria become electron-dense, and their DNA is clearly visible. On that day, lipids as well as starch are being depleted. The peroxisomes change in structure every day, from D-2 to D-day. It has also been demonstrated by histochemical techniques that during anthesis the activity of cytochrome c oxidase (3,3-diaminobenzidine as a substrate) decreases whereas the activity of NADH dehydrogenase [tetrazolium salts: nitro-blue tetrazolium chloride (NBT) or neotetrazolium chloride (NT) in the presence of NADH], increases. Oxygen consumption of isolated mitochondria from the D-day appendix was inhibited in the presence of the two tetrazolium salts to a different degree: oxidation of NADH in the presence of NBT was the most sensitive to inhibition, more so than the oxidation of malate and succinate. NT was less effective as an inhibitor in the presence of those three respiratory substrates.

Studies on the cell wall starch of Hericium.

According to one of the more interesting scientific sagas of this century, the prim and proper French judge who discovered the phenomenon of pseudocopulation between certain Algerian wasps and the flowers of the orchid Ophrys speculum waited for 20 years before publishing his “unbelievable” results. Between 1965 and today, we have found ourselves in a somewhat similar position, after having been confronted with the (certainly unorthodox! ) occurrence of a starchlike substance in the cell walls of the icicle, or hedgehog, fungus, Hericiurn. In October 1971, however, McCracken and Dodd published the results of their completely independent studies of this hyphal wall starch. Since the agreement between their findings and ours seems to be quite satisfactory, there is now no good reason to withhold our results any longer. The typical starch of green algae and higher plants is traditionally ascribed the following three attributes: ( 1 ) it is produced in plastids; ( 2 ) it is ultimately found in the form of granules or composite granules; and ( 3 ) it is (not unrealistically) thought of as a reserve substance. Textbooks list the lack of plastids in fungi as one of the main differences between this group and the algae; obviously, then, when starch is found in fungi, it must have been produced in some other cellular site. The presence of the compound in the walls of fungal spores, asci, or hyphae,”-‘ rather than in special granules in the cytoplasm, argues against its having a role as a reserve material, although it does not entirely exclude such a possibility. Study of the literature reveals that “amyloidity,” a feature used for its diagnostic value in fungal taxonomy since 1869,5 can in the Basidiomycetes be observed in the spore walls of at least 35 genera of Agaricales (albeit it usually does not occur in all species of a given genus). It also manifests itself in the spores of at least 20 genera of the Aphyllophorales. Among the Ascomycetes, nine families of Discomycetes display amyloidity in the wall of the ascus,‘; while three major families of Pyrenomycetes possess an amyloid apical ring in that organ.7 The spiny fruiting bodies, or carpophores, of species of Hericium offer special advantages in the study of fungal amyloid compounds, because the latter (as evidenced by a very intense blue iodine reaction) occur in the hyphal walls as well as in the spores; since one carpophore may weigh several pounds, there is thus no dearth of material for analysis. The carpophores can be preserved in 70% ethanol, or can be dried at 60-70” C for subsequent grinding and extraction of the amyloid with boiling 1% ethanol, under reflux. Most of the extractions were made from fruiting bodies of Hericium ubietis forma abietis

Nymphaea Revisited: A preliminary communication: A preliminary communication

ABSTRACT A number of pollination syndromes within the genus Nymphaea are examined. Adaptive radiation has created a wide range, from beetle-pollination with production of solid food bodies for the visitors to pollination by small Hymenoptera and syrphid flies with production of a pool of stigmatic fluid in which, on the first day of anthesis when the flower is functionally pistillate, pollinators drown. In the latter category, there is striking sophistication in the features that ensure proper deposition and germination of the pollen grains. In the tropical water lilies examined, the sugar level of the stigmatic fluid was 1%-1.5% which is well below the threshold of perception for honeybees regardless of the nature of the sugar; fructose and glucose were present in roughly equal concentrations. In Nymphaea odorata, a temperate zone water lily, the sugar concentration was about 3%, a considerable part of which was sucrose; glucose and fructose were again present in almost equal concentrations. No obvious b...

The energetic state of the thermogenic appendix of the voodoo lily inflorescence. A 31P-NMR study

Abstract Using 31 P-NMR, we have monitored the metabolic changes in the phosphorus compounds of the appendix, the upper thermogenic part of the inflorescence, of Sauromatum guttatum (voodoo lily). Qualitative, in vivo spectra from D− 6 (6 days before heat-production; the day of heat-production is designated D-day). D − 3, D − 2, D − 1. D-day, D + 1 and D + 2, revealed fluctuations in the concentration of the vacuolar and cytoplasmic inorganic phosphate (P i ) relative to an internal standard. From D − 6 to D − 2 the vacuolar P i peak was not prominent relative to the other peaks. In the morning of D − 1, an increase occurred in the vacuolar and the cytoplasmic P i levels. Later on, during development, these levels gradually declined. On D-day, changes in vacuolar and cytoplasmic pH were detected during heat-production. The cytoplasmic pH decreased from 7.7 to 7.2 while that of the vacuole increased by almost one pH unit from 5.8 to 6.7. Perchlorate extract spectra from D − 4, D − 1 and D-day appendices confirmed the observed changes in P i intensity. These spectra also revealed qualitative changes in the content of ATP and ADP. Their sum decreased during development, reaching its lowest level on D-day at the peak of heat-production between 11:00 and 14:00 (as determined by high performance liquid chromatography of the perchlorate extracts). This suggests that in the early morning of D-day, when heat-production starts, around 9:00 phosphofructokinase, the key enzyme in glycolysis, is not activated by a change in the intracellular ATP/ADP ratio, but by other effector(s).

Isolation of trans-Aconitic Acid from the Moss Mnium affine

The water-soluble substance occurring in high concentration (up to 6 percent of the dry weight) in Mnium affine Bland. and forming the main fraction of the plant acids there, has been identified as trans-aconitic acid by nine different criteria. Evidence is presented in favor of the concept that the trans form in this case is the natural isomer and not an artifact derived from cis-aconitic acid. Information is given on the distribution of aconitic acid in other mosses and in liverworts.