Shoe Box of Notes on Plants - Plant Facts and References

From My Shoe Box of Notes

Important Puzzle Pieces

REFERENCES

Plant Analysis and Fertilizer Problems
Edited by Walter Reuther 581.19 - C714
Plant Chemiculture
Dawson 581.1 - D27
Plant Regulators in Agriculture
Tukey 581.19 - T916
Diagnosis of Mineral Deficiencies in Plants
Thomas Wallace, M.C., D.Sc., A.I.C. 581.19 - W194
Soilless Growth of Plants
Ellis 581.1 - E47
International Series of Monographs on Pure and Applied Biology
Plant Physiology Division.
Mineral Salts Absorption in Plants
Sutcliffe 581.1 - S965
Chemical Gardening for the Amateur
Connors 581.1 - C752
The Merck Index - Sixth Edition - 1952
Hand Book of Physics and Chemistry
Ten Talents
Dr. Frank J. Hurd, D.C. and Rosalie Hurd, B.S.
Plant Metabolism
H. E. Street 581.1 - S915
Nitrogen Fixation in Plants
W. D. P. Stewart 581.1 - S8495
Plant Pathology
John Charles Walker 581.2 - W182a2
Chemistry of Plants
E. V. Miller 581.19 - M647

Elemental Constituents of Plants
Chemical analyses of higher plants in general have revealed the presence of 40 or more elements. Up to the present time, however, plants physiologists have proved that only 16 [18 today] of these elements are indispensable to the plant. [However, we know today that 28 or more are required by humans.] Of these elements, Carbon, Hydrogen, Oxygen and Nitrogen are present in larger quantities than others, being combined to form various components of the cell wall and protoplasmic materials. Likewise Sulfur and Phosphorus may occur in the protoplasm as constituents of proteins or other important organic compounds, though not in as high a concentration as that of C, H, O, N.
The discussion in this chapter will be limited to the mineral or inorganic constituents. This eliminates Carbon, Hydrogen and Oxygen. Sulfur and Phosphorus are usually included among the inorganic constituents although a certain portion of these two elements may exist in organic compounds and may be lost in conventional methods for determining ash content of plant materials.
In table 11 will be found the results of chemical analysis of the whole corn plant. It is apparent that the mineral elements do not comprise a very large proportion of the plant. Total ash of plants may vary roughly from 1 to 15 per cent of the dry weight. Fleshy fruits and woody tissues are usually very low in minerals, often containing 1 per cent or less of ash. Both qualitative and quantitative composition of plants or plant tissues may vary with environmental conditions.
A study of the inorganic constituents of plants should be of interest to research workers in several fields, such as nutrition medicine and others, because plants constitute direct or indirect sources of many of the elements which are essential to animals, including man. We shall therefore discuss several of the mineral elements, indicating either the compound or the part of the plant where one can expect to find a particular element. And, where possible we shall indicate the plants or plant organs which tend to accumulate certain elements.
Table 13 contains a list of the elements essential to plants and those essential to animals. Ten of those (Cu, Ca, Mg, K, P, S, Fe, Mn, Zn and Cl), are required by both types organisms. But in addition to these ten there are two, B and Mo, required by plants, and five others, Na, Co, I, and Si, which are required by animals. Two borderline cases (Cl and Co [both of these are required to make vitamins for humans]) are extremely interesting. In view of the work of Broyer and associates we have added Chlorine to the list of elements essential to plants.

SELECTED QUOTES

[Me facts List]

{1} Plants absorb their nutrient salts in the form of ions.
{2} The type and concentration of the nutrient solution depends on the species of plant grown, the time of year (Temperature, Day / Night Ratio), available light and the reaction of the water solution with the soil, sand, rocks or other rooting substance as the growing medium and the container in which it is contained.
{3} If seedlings grow too spindly, they should be grown at a lower temperature, particularly the night temperature, Given a greater intensity [and/or duration] of light particularly the blue portion of the spectrum and / or the concentration of the nutrient solution can be increased by adding more of the major elements. The concentration of the nutrient solution will have a dramatic effect on the type of seedling produced. The idea is to produce a short-stemmed, stocky, dark green seedling that is not to succulent i.e. not too soft. Control of the solution plays a very important role, but it is very easy to over react in the preparation and produce conditions that are toxic to the plants.
{4} Traces of Radium and Uranium increase the growth rate of plants.
{5} The wall of each living cell is a permeable (osmotic membrane), that is a membrane that will permit the passage through it of salt ions in solution. The principle is that of balance, for the solutions on both sides of the membrane tend to come to the same density or concentration. The ions that are absorbed through the root hairs are soon transported by osmosis, through the different cell walls to some other part of the plant where they are combined with formaldehyde and its products to form the various organic compounds associated with plant life. The contents of the cells (protoplasm) are in the form of colloids which cannot pass through the membrane. If the density of the solution outside the root hair or other cell is greater than that inside, only water passes outward to bring about the balance. [High external concentrations can cause the plant to wilt.] The pressure which causes the movement of liquid in or out is called osmotic pressure. Osmotic pressure is often expressed in atmospheres (760 mm Hg) about 14.7 psi.
{6} Concentration is the amount of a substance in weight, moles or equivalents contained in that unit volume.
{7} Plants will absorb nutrients in proportion to the amount that is present in the nutrient solution within certain limits determined by the needs of the plants. To a certain degree plants can react by concentrating an element or limiting an element in themselves. But generally they always contain at least some of everything found in their growing medium.
{8} Nitrate and ammonium Nitrogen taken into the plant, change over to proteins, the rate depending on environmental conditions.
{9} Under [pure] red light rays, plants behave in some ways as if they had no light. Plants grown under red light with blue excluded tend to stretch up as though they were grown in the shade. Such plants do not produce much sugar, and are very succulent or soft. This type of growth does not have substance enough to set fruit or produce strong stems or flowers.
{10} Blue light is very efficient in producing sugar and other carbohydrates, but unless it is accompanied by red light there is a stunting effect. The blue light alone tends to harden plants which causes carbohydrates to be stored up, but the total amount of dry matter under such conditions probably would be less than if plants received all the rays of sunlight.
{11} The ultraviolet is thought to be important in the production of vitamins by the plant, but it has not been proven. Large flower and vegetable yields have been obtained where ultraviolet light light is scanty. [Studies have shown that yields can be increased by filtering sunlight with a single pane of window glass.]
{12} The light from a carbon arc is harmful to the growth of plants unless the ultraviolet light is screened out.
{13} People who have attempted to grow tomatoes during the winter months have seen flowers drop off because there was insufficient starch in the tissue to set fruit. Flowers will form, but fruit or seed can form only when the plant leaves make a large amount of carbohydrates, this demands the shorter wave lengths of light. It is quite possible to grow plants without sunlight, if the proper proportions of light rays are supplied for the correct duration of time, in the correct intensities at the correct growing temperature.
{14} The more intense the light source the more Ammonia Nitrogen can be utilized by the plant. [Plants require almost all of their nitrogen in the form of nitrates. The Ammonia radical itself is used for some plant structures, but if Ammonia is placed in the plant root environment it must first be reduced through bacterial action before the plant can absorb it in any quantity.]
{14a} Intensive amounts of infra-red light is quite detrimental to most plants, the stomata being eventually closed by too much of this light.
{15} Plants seem to grow well without ultraviolet light.
{16} There are definite light-dark ratios for different plants.
{17} Carbon dioxide enrichment produces larger plants.
{18} Well aerated roots produce larger plants.
{19} Dust clogging the stomata can reduce the yield by as much as 100%.
{20} Toxins given off by some plants in their mining operations and defense mechanisms are definitely injurious to [many] other plants until broken down by soil processes. In soilless growth methods, these acids tend to accumulate, particularly if there is a deficiency, and do reach toxic levels.
{21} If the growing tip of a growing plant is cut off, the stem will cease to grow. By this practice a more bushy plant (with more numerous buds) is generally produced.
{22} Galvanized containers or piping will likely lead to Zinc poisoning.
{23} Excessive Fluorine or Chlorine causes root injury.
{24} Coal tar and pine tar, caulking containing Lead, many paint pigments and oily materials are toxic to plants or plug the root or leave pores.
{25} Under high light intensities plants require more Iron.
{26} Certain bacteria live on the roots of plants deriving their food from the plant, but, at the same time, produce nodules on the plant roots by means of which the bacteria are able to take free Nitrogen [molecular] from the atmosphere and produce nitrates which can be utilized by the plants. [actually they produce ammonia which is reduced by other bacteria to nitrates, which are then absorbed by the plants.] [Rhizobia Bacteria]
{27} A strong solution concentration of fertilizing salts result in a stiffer harder growth.
{28} Blights usually result from important physical conditions.
{29} For germination of seeds a high temperature starts activity quickly. It is important to get these processes which cause the seed to germinate into activity as soon as possible. Seeds which stay dormant in a cold wet soil too long may start to decay before it germinates. After the seedling is above the surface of the growing medium, the temperature should be lowered.
{30} Plants have a minimum and maximum temperature beyond which activity ceases. Some plants grow well at low temperatures and become inactive at room temperature.
{31} A plant may show Nitrogen deficiency symptoms when the fault may be in the surrounding temperature or the amount of light that is available.
{32} The symptoms of too high temperatures are yellowing of the older mature leaves with gradual death and drying of the tissue. The plants lose their green color, the new leaves are small and the general appearance is that of a rangy plant with abnormally long stems between the branches. In plants which have a long narrow leaf, the tips turn yellow and die gradually.
{33} 581.1 Dd27 pp42 Regardless of the possible cause, we have noticed that plants grow better in metal tanks than in wooden containers.
{34} The fertilizing action of K is tripled in the presence of Na. Ca counteracts the toxic influence of Mg, K and other elements. Iron is antagonistic to Mn and prevents Mn toxicity. Plants of the vine type such as cucumber, squash and tomatoes seem to be able to absorb larger quantities of salts than do plants with harder stems, but the softer plants suffer sooner from a deficiency of salt elements than do the hard stem plants.
{35} Whereas certain chemicals are antagonistic to each other in their reactions, the relative balance between the compounds furnished in a formula is a matter of considerable importance such as;

Fe vs Mn
Ca vs Mg
Ca vs K
Ca vs Na
[Li vs Na].
{36} The mutual relation of all of the elements is controlling function of the plant.
{37} Ferrous compounds may become highly toxic.
{38} Decreasing ratio of Ca to Mg, increases assimilation of P.
{39} Pollinate when the temperature is high; Wait until the petals begin to wither a little, as then, the pollen sac will burst.
{40} A very sudden decided droop may be caused by getting the solution too strong, a solution that is too weak, or a temperature that is too high.
{41} Plant cells accumulate salts to concentrations higher than those which occur in the medium, a process which clearly requires a expenditure of energy.
graphic insert [gf1]
{42} Brooks (1929) suggested that cations and anions might be absorbed continuously in exchange for ionic products of metabolism. If there is for instance, a continual production of Hydrogen ions inside a cell so that their concentration on one side of a cation-permeable / anion-permeable membrane is maintained at a higher level than on the other side, cations e.g. K ions can be absorbed against the existion concentration gradient, by simultaneous production of hydrogen and bicarbonate ions, accumulation of a neutral salt can be achieved. Sollner (1955) demonstrated this principle.
{43} The Belgian Electrical Society is reported to have obtained the following increase in production by filtering out the sun's Ultraviolet radiation with a single pane of window glass:

Cereals 20-40%
Beets 35%
Strawberries 35%
Potatoes 50%
{44} Hornert (1933) studied the effect of Ph on Phosphate absorption by sugar cane plants and found the result to be consistent with the view that only univalent ions are absorbed to an appreciable extent.
{45} Ions in a solution affect the absorption of one another in a variety of ways and the more ion species there are present the more complex the situation becomes.
{46} The rate at which individual ions are absorbed is determined by the ratio of their concentration to those of the other ions in the medium, rather than the concentration itself.
{47} Only cells capable of growth have the capacity for absorbing salts. When metabolism begins to decline in cells, the cells enter either a state of senescence or of dormancy. senescent cells gradually degenerate and release salt to their surroundings, but dormant cells on the other hand can be stimulated to metabolize activity, synthesize protein and absorb salt again under suitable conditions.
{48} Root systems of many plants have fungi associated with them to form mycorrhiza, some evidence that these plants grow more actively and have a higher ash content {Routienand Dawson (1943)} fungus causes stimulation of respiration and additional release of Hydrogen ions from the host, for use in exchange reactions with the soil or medium producing organic substances which form chelates with inorganic ions in the medium, the plants thus can more readily absorb the free ions.
{49} A mineral is an inorganic substance occurring naturally in the earth and having a consistent and distinctive set of physical properties e.g. color hardness and crystalline structure, and a composition that can be expressed by a chemical formula expressing the elements involved and the form of their occurrence.
{50} Light and high temperatures increases excreted fluids, metabolic inhibitors reduce it.
{51} Ruhland estimated that there are about 700 glands per square millimeter of leaf surface in Limonium Gmelinii and these may excrete up to 1 ml. of liquid per hour, containing perhaps 0.05 mg of NaCl.
{52} Salt absorption is mainly an active process. The formation of a specific complex between the ion transported and an organic constituent of the cytoplasm. Cytoplasmic proteins may act as carriers.
{53} Salts diffuse as ions across the cellulose cell walls, the water filled spaces of which comprise the "free space" of the cell to the surface of the cytoplasm, where they become attached to protein molecules located in the surface membranes. As a result of protein synthesis, new sites are created to which salts may be bound and uptake from the medium continues as long as newly synthetized protein is being exposed at the external surface. Cytoplasm is in a constant state of flow (cyclosis) which means that the constituent proteins are mobile and probably move periodically from the surface into the bulk of the cytoplasm carrying bound ions with them. Pinocytosis may play an important part in this process. Within the cytoplasm, proteins are continually being broken down and reformed, a process referred to as turnover, which involves attachment of the protein to a template or former which is believed to be a molecule of ribonucleic acid (RNA). When a protein molecule complexes with a RNA molecule it is probable that some or all of the bound ions are released. Release of ions may occur predominantly in localized regions of the protoplasm which are rich in RNA. Such a group of free ions may then attract water from their surroundings to form a small aqueous vesicle containing a concentrated solution of salt. Such vesicles are a prominent feature of cytoplasm when viewed with the electron microscope.
{54} Glycophytes or Glyptophytes (salt sensitive) plant growth is retarded when the salt content of the medium exceeds a rather low value. (shallow rooted plants) Large shoot to root ratios, which results in poor water absorption capability in relation to transportation.
{55} Halophytes grow habitually on soils or in mediums containing a high concentration of salts and are seldom if ever found elsewhere.
{56} As may be expected conditions leading to high transpiration e.g. high light intensity and low humidity, may induce salt damage at concentrations favoring low rates of transpiration.
{57} Slow growing species tend on the whole to be more salt tolerant than those which grow rapidly.
{58} Since Nitrates represent Nitrogen in a highly oxidized state it is obvious that a considerable amount of reduction must occur before the Nitrogen can be incorporated into amino acids. [Mo is required for this.]
{59} It has long been held that the reduction of Nitrate Nitrogen proceeds by way of nitrates through intermediate steps such as the formation of hyponitrous acid and hydroxylamine to Ammonia. Nitrate - (Nitrate reductase) - Nitrite - (Nitrite reductase) - intermediate - hydroxylamine - (hydroxylamine reductase) - Ammonia. (George C. Webster - above sequence).
{60} Nitrate reduction in leaves appears to be activated by a light mechanism, for in young leaves at least, the process is closely linked with Carbon dioxide reduction during photosynthesis. It is probable that some transitory compound combines with one of the intermediate products of photosynthesis to form amino acids on related Nitrogenous compounds.
{61} 22 amino acids occur in nature as constituents of proteins and a number of others have been identified in hydrolysates.
{62} From less than a hundred to over 100,000 amino acids are required for building a single protein molecule.
{63} The property of the individual protein depends upon the particular amino acid residues in the molecule. Each species of plant or animal produces characteristic proteins not found in other species. The molecular weight of proteins may vary from about ten thousand, to several hundred thousand, or even several million.
{64} During the early phases of seed germination the principal reactions involving proteins consist of the hydrolysis of these compounds into simpler substances. Catabolic changes of this type take place to some extent during later stages of growth but are not so dominant as are the synthetic reactions. During senescence catabolic changes again predominate.
{65} Within the living cell, whether plant or animal, hundreds of chemical reactions are taking place in an orderly regulated manner. The precise regulation of these chemical reactions is brought about by enzymes. An enzyme may be defined as an organic catalyst which is produced in the living cell. These catalysts are effective in very small quantities and they are are very specific, most often working with another, a co-enzyme which maintains the vitality of the first. i.e. A single molecule of catalase can bring about decomposition of five million molecules of (H₂O₂) per minute at 0 degrees C. In 1897 Buchner discovered that an extract of crushed lifeless yeast cells could cause the fermentation of sugar, thus demonstrating for the first time that the orderly regulation of chemical reactions involved in living processes is not a characteristic of protoplasm as a whole. It proved that enzymes can be isolated from the cell and that they are capable of carrying on their work outside the confines of the cell.
{66} Enzymes are involved in splitting sucrose, hydrolyzing fats and the cleavage of proteins. They participate in the transfer of Hydrogen atoms from one molecule to another.

a) Hydrolyzing
b) Desmolyzing
c) Causes a breaking of a molecule by the addition of water.
Digestive enzymes are typical of this group. They catalyze such reactions as the hydrolysis of starches to sugar, fats to fatty acids and glycerol, proteins to polypeplides and amino acids.
Desmolyzing enzymes catalyze reactions other than hydrolyzing. They play dominant roles in the chemical reactions involved in respiration and fermentation. They catalyze the breaking of linkages between Carbon atoms. The addition of an atom or an atomic group to a molecule or the removal of an atomic or atom from the molecule, and the shifting of atoms or groups from one part of a molecule to another part. Those enzymes that have been isolated, have been found to be proteins. More than 67 enzymes have been isolated studied. [As of publishing date] Copper, Iron, Manganese, Zinc are constituents of enzymes. Ascorbic acid oxidase is a Copper protein.
{67} Fe, Mn, Zn, and Mg act as enzyme activators.
{68} Enzymes are large molecules. They are readily denatured by treatment with heat, ultraviolet, or by heavy metal ions, (i.e. Silver, Lead, Mercury) and by the action of concentrated acid or alkali.
{69} The most characteristic property of enzymes is their specificity.
{70} The rate of loss of enzyme activity (in aqueous solution) becomes appreciable at 50 degrees centigrade and is quite rapid at 60 degrees centigrade and above. Enzymatic reactions therefore have an optimum temperature and the rate of reaction decreases at temperatures above the optimum.
{71} It is possible to vary the heat stability of an enzyme. Stability is affected by the presence of a substrate, by salt content and PH of the solution. In the solid state and in the absence of moisture, enzymes are more stable, they then return to full activity until the temperature becomes high enough to "char' them.
{72} Certain substances may act as inhibitors of enzyme action. Since enzymes are proteins in nature it is quite obvious that they should be inactivated by proteins or precipitants. Among this group of inhibitors are the soluble salts of heavy metals such as Mercury, Silver, or Copper. [and others] Michaelis-Mente
{73} In some enzyme systems a calculation can be made of the number or substrate molecules which are converted to end products per molecule of enzyme per unit of time. The number of molecules is termed the "turnover" number of enzymes. The turnover number has been reported to be as large as five million per minute. The point at which the concentration ceases to have an effect is termed the limiting rate. THe concentration of substrate at the point where rate of reaction is equal to one half of limiting rate is termed the "Michaelis Constant" for the particular enzyme. The method by which an enzyme speeds up reaction rate consists of the lowering of the apparent activation energy.
{74} Enzymes differ from the older conception of a catalyst in two ways. First the enzyme is produced within the living cell, whether it acts at the scene of production or not. In the second place an enzyme DOES participate in the reaction it catalyzes even though it does not appear as part of the end product. It is now known that a critical point in an enzymatic process consists of a formation of a complex between enzyme and substrate. With few exceptions plant juices are slightly acid in reaction thus contrasting them with animal fluids. [which are slightly alkaline]
{75} Aliphatic acids present in plants do not ordinarily occur exclusively in the un-dissociated state. A certain portion of the total acid is combined with mineral cations forming an organic acid salt. It will be obvious that such a combination constitutes a buffer system in plant tissues. THis is true of the acids in citrus fruits in which form, from 50 to 70% of the total cations may be associated with organic acid anions.
{76} Citrus fruits are high in Magnesium and Potassium.
{77} F. Kogel and co-workers in Holland, isolated from biological sources, two materials which possessed very active growth promoting characteristics. The compounds were termed auxin (a) and auxin (b).

Auxin (a) - human urine - Auxentrolic acid.
Auxin (b) - corn germ oil - Auxenoloic acid.
Heteroauxin - human urine - Indole-3-acetic acid.
Indole-3-acetic acid is a naturally occurring growth regulator. This compound is active in inducing root formation.
{78} Among these synthetic substances were homologs of Indole-3- acetic acid such as Indole butyric and Indolepropionic acids, <><>-napthalene-acetic acid.
{79} Urea is formed in the enzymatic hydrolysis of orginine and may be one of the products of oxidation of amino acids in tissues which are deficient in carbohydrates.
{80} Sterols are cylic alcohols of high molecular weight. Those occurring in plants are termed phytoslerols. Ergosterol (C₂₂H₄₃OH) is a typical example of plant sterol. First discovered in Ergot it is now known to be widely distributed in plants and lower organisms. When irradiated, this compound is converted to the antirachitic vitamin (Vitamin D). Sterols can serve as the alcohol in waxes.
{81} Compound fatty acids in fats may be of two kinds: Saturated and unsaturated. Unsaturated fatty acids are so called because they contain one, two or more ethylenic linkages variously located along the hydrocarbon chain.
Unsaturated fatty acids which are often found in natural fats are Linoleic (C₁₈H₃₂O₂), Linolenic (C₁₈H₃₀O₂) and Erucic (C₂₂H₄₂O₂). Linolenic and Linoleic acids are essential to man.
{82} Essential Oils are volatile oils and over 500 different chemical compounds have been identified in essential oils.
Essential Oils ordinarily occur in localized regions of the plant. Marked quantities of essential oils are produced by roughly 2000 species of plants. It is possible that all known species are capable of producing volative oils to some extent.
The biochemical significance of essential oils to plants is not clearly understood. Many of these oils are attractive to insects and thereby assure cross-fertilization in plants. Others are repugnant to animals and in this manner serve to preserve the plants from extinction. But, it is in the economy of man that essential oils have come to play an important role. Many are employed for flavoring of foods, beverages, pharmaceuticals, cosmetics and tobacco. In addition, essential oils find extensive use in medicine as local stimulants, mild antiseptics, local irritants, parasiticides, sedative, urinary antiseptics, diuretics and antiemetics.
{83} Plant pigments:
I. Ether-soluble or plastid pigments

A. Chlorophylls (green)
B. Cirotenoids (orange)

1. Carotenes
2. Xanthophylls and Xanthophyll derivatives
II. Water-soluble or vacular pigments

A. Anthoryanins (red, blue, purple)
B. Anthoxanthins (yellow)
{84} Chlorophylls: The amount of chlorophyll (A) {C₅₅H₇₂O₅N₄Mg}, is roughly three times that of chlorophyll (B) {C₅₅H₇₀O₆N₄Mg}.
Structurally both molecules consist of four pyrrole rings with an atom of Magnesium (Mg) in the center. (B) differs from (A) in having a CHO group in place of a CH₃ radical. They are both methytphyty esters of a complex acid called Chlorophyllin.
So far as it is known chlorophyll (A) is present in all photosynthetic organisms except green and purple bacteria. Chlorophyll (B) occurs in higher plants and in green algae, But is not present in most other algae. Several other types chlorophyll are now known. Chlorophyll (C) has been reported in diatoms and brown algae which do not contain chlorophyll (B). Red algae contain a fourth type of chlorophyll (D), but no (B). Bacterioxhlorophyll is found in purple bacteria. Bactercoviridin is the pigment which occurs in green bacteria and is similar to the chlorophylls. All these pigments contain magnesium. All the chlorophylls possess the property of fluorescence, i.e. when illuminated, they re-radiate light of wavelengths other than those absorbed. Thus an alcoholic solution of chlorophyll (A) is green by transmitted light and deep blood red by reflected light. Ether solutions of both chlorophylls (A) and (B) exhibit maximum absorption in the blue violet region and a secondary maximum in the short red. It was found that the wavelengths of light most efficient in bringing about the destruction of carotenoids were the same wavelenghts that are most strongly absorbed by protochtorophyll the final precursor of chlorophyll
{85} Photosynthesis may be defined as the process whereby green plants convert the energy of sunlight into potential energy of reduced Carbon compounds, molecular Oxygen being evolved simultaneously in a two part process:

1.) The breakdown of water with the release of Oxygen
2.) The reduction of Carbon dioxide by hydrogen (Carbon fixation).
{86} Autumal coloring results from a change in pigmentation of plants as cool weather ensues. The production of chlorophyll retards and hidden pigments become apparent. Some plants develop anthocyamin, pigments that develop red and purple.
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