PALLADIN, VLADIMIR IVANOVICH

(b. Moscow, Russia, 23 July 1859; d. Petrograd [now Leningrad], U.S.S.R., 3 February 1922)

biochemistry, plant physiology.

Palladin attended the Gymnasium in Moscow and in 1883 graduated from Moscow University, where he remained to prepare for a career in teaching. In 1886 he defended his thesis, “The Meaning of Oxygen for Plants,” for the M.A. From 1886 Palladin was an instructor and then a professor of botany at the Institute of Agriculture and Forestry in Novaya Aleksandriya, and from 1889 he was professor of botany at Kharkov University. In 1889 he defended his doctoral dissertation, “The Influence of Oxygen on the Decomposition of Proteins in Plants,” at the University of Warsaw, to which he had transferred in 1897. In 1901 Palladin was appointed to the chair of physiology at St. Petersburg University and in the Higher Courses for Women. Here Palladin began his lengthy teaching career; among his students were the physiologists S. P. Kostychev, N. A. Maksimov, and D. A. Sabinin.

Palladin was the author of two well-known textbooks: Fisiologia rasteny (“Plant Physiology”), which for more than thirty years was used as the basic text in all Russian higher educational institutions, and Anatomia rasteny (“Plant anatomy”). In 1906 he was elected corresponding member of the Academy of Sciences, and in 1914 academician. He then retired from St. Petersburg University and conducted his scientific work at the academy.

In his two graduate dissertations Palladin showed the existence of a close bond between the two most important biological processes: respiration and protein metabolism. He established that the carbons formed in plants are the products of the incomplete oxidation of proteins, for which the assimilation of oxygen from the air is necessary. Palladin also studied the process of evaporation of water, the content of proteins and mineral substances, the process of respiration in green and etiolated plants, and the conditions under which etiolated plants become green. He then advanced to questions concerning the chemical physiology of plants, first studying the transformation of nitrogenous substances and the energy processes in plants, and then studying the process of plant respiration, to which he devoted the last year of his life.

Three basic stages can be noted in Palladin’s research into plant respiration. First, basing his work on the discovery of oxidizing enzymes at the end of the nineteenth century, he concluded that the oxidation-reduction processes, which represent a chain of strictly coordinated enzyme reactions, are the basis of respiration in plants. His monograph “The Respiration of Plants as the Sum of the Enzyme Processes” (1907) attracted much attention from Russian and foreign scientists; it clarified the details of the anaerobic and aerobic phases of respiration from the point of view of the activity of specific enzymes, which transform in succession the intermediate products of respiration. A careful study of the action of the oxidase and peroxidase enzymes showed that their oxidizing energy is limited and cannot have an oxidizing effect on the respiratory substrate: carbohydrates or the products of carbohydrate decomposition. In the second stage of his research into respiration, Palladin sought to discover the intermediaries between oxidases and carbohydrates. They proved to be aromatic compounds of the polyphenol type, which he called respiratory chromogens. Palladin formulated the role of the respiratory chromogens in “The Significance of Respiratory Pigments in the Oxidizing Processes of Plants and Animals” (1912). A new point in this work was the discovery of intermediate agents: carriers of oxygen. But the process of respiration was still understood in accordance with Lavoisier’s hypothesis of a process analogous to burning. In the last stage of his research Palladin showed that this hypothesis was false. He stated that respiratory chromogens do not activate the oxygen in the air; instead, they activate the hydrogen in carbohydrates with the aid of the enzyme reductase (dehydrogenase). Respiratory chromogens were thus carriers of hydrogen, not oxygen. He discovered that simultaneously with the decomposition of water, the of which goes into the oxidation of the respiratory substrate and forms carbonic acid, the hydrogen is temporarily bonded to the respiratory pigment. This work predated that of H. O. Wieland, with whom the phenomenon is usually associated.

This first phase of respiration is the most basic. It occurs under anaerobic conditions and the carbonic acid separated out is formed by the respiratory substrate (carbohydrates), not by atmospheric oxygen. The oxygen in the air takes part only in the second phase of respiration, interacting with hydrogen in the pigments and restoring their activity. Palladin’s theory of respiration brought him an international reputation. His concept of the active role of hydrogen was new, as well as his theory of the active participation of water in the oxidation-reduction process of respiration.

BIBLIOGRAPHY

I. Original Works. Palladin’s major works include “Bedeutung des Sauerstoffes für die Pflanzen,” in Byulletin’ Moskovskogo obschestva ispytalelii prirody, 62 , no. 3 (1882), 44–126; Vliyanie kisloroda na raspadenie belkovykh veshchestv v rasteniyakh (“The Influence of Oxygen on the Decomposition of Albuminous Substances in Plants”; Warsaw, 1889), which also appeared in Bericht der Deutschen botaniscghen Gesllschaft, 5 (1887), 326–328, 6 (1888), 205–212, and 7 (1889), 126–130; Fiziologia rasteny (“Plant Physiology,” Kharkov, 1891; 9th ed., Petrograd, 1922); “Fiziologicheskie issledovanica nad etiolirovannymi listyami” (“Physiological Research on Etiolated Leaves”), in Trudy Obschestva ispytatelei prirody pri Imperatorskom khar’ kovskom universite, 26 (1892), 67–68; this article also appeared in Bericht der Deutschen botanischen Gesellschaft, 9 (1891), 194–198, 229–232; “Recherche sur la respiration des feuilles vertes et étiolées,” in Revue générale de botanique, 5 (1893), 449–473; and Anatomia rasteny (“Plant Anatomy,” Kharkov, 1895; 7th ed. Petrograd, 1924).

Palladin’s subsequent writings include “Dykhanie rasteny kak summa fermentativnykh protsessov” (“Breathing of Plants as the Sum of Enzyme Processes”), in Zapiski Imperatorskoi akademii nauk. Fiziko-Matematicheskomu, ser. 8, 20 (1907), no. 5, 5–64; “Die Atmungspigmente der Pflanzen,” in Hoppe-Seyler’s Zeitschrift fur physiologische Chemie,55 (1908), 207–222; “Znachenie vody v protsesse spirtovogo brozhenia i dykhania” (“The Importance of water in the Process of Alcohol Fermentation and Breathing”), in F. N. Krasheninnikov, ed., Sbornik statey; posvyashchenny K. A. Timiryazevy ego uchenikami v oznamenovanie Semidesyatogo dlya ego rozhdenia (“A collection of articles offered to K. A. Timiryazev by his pupils in honor of his seventieth birthday,” Moscow, 1916), pp. 1–34; and lzbrannye trudy (“Selected Works”; Moscow, 1960), which gives a bibliography of Palladin’s works.

II. Secondary Literature. For works on Palladin and his work, see S. Kostychev, “V. I. Palladin. Nekrolog” (“V. I. Palladin, Obituary”), in Zhurnal Russkago botanicheskogo obshchestva, 7 (1922), 173–186; C. N., “W. Palladin,” in Biochemisch Zeitschrift, 130 (1922) 321–322; S. D. Lvov, “V. I. Palladin kak osnovopolozhnik sovremennogo uchemia o dykhanii” (“V. I. Palladin as the Founder of the Contemporary Theory of Breathing”), in Vestnik Leningradskogo gosudarstvennogo universiteta, nos. 4, 5, 50–71; “Zesedanie i doklady, posvyashchennye pamyati V. I. Palladin” (“Session and Reports Devoted to the Memory of V. I. Palladin”), in Biokhimiya, 17 no. 2 (1952), 246–254; B. A. Rubin, “Idei V. I. Palladina i sovremennoe sostoyanie uchenia o dykhanii rasteny” (“V. I. Palladin’s Ideas and the Present State of the Theory of Breathing”), in Vestnik sel’ skokhozyaistvennoi nauki, no. 9(1960),39–49; and E. M. Senchenkova, “Vydayushchysya russky biokhimik i fiziolog rasteny. K stoletiyu so dyna rozhdenia V. I. Palladin” (“Distinguished Russian Biochemist and Plant Physiologist. For the Hundredth Anniversary of the Birthday of V. I. Palladin”), in voprosy istorii estestvoznaniya i tekhniki, no 9, (1960), 134–138

E. M. Senchenkova