MAKSIMOV, NIKOLAY ALEKSANDROVICH

(b. St. Petersburg [now Leningrad], Russia, 21 March 1880; d. Moscow, U.S.S.R., 9 May 1952)

plant physiology.

After graduating from the Gymnasium in 1897, Maksimov entered the natural sciences section of the department of physics and mathematics of St. Petersburg University. He graduated in 1902, then remained to prepare for a professorship. In 1905 he became an assistant in the department of botany of the St. Petersburg Forestry Institute. In 1910 Maksimov traveled to Java, where he worked in the Buitenzorg (now Bogor) Botanical Garden, In 1913 he defended his master’s thesis, “O vymerzanii i kholodostoykosti rasteny” (“On the Frost Kill and Cold Resistance of Plants”), at St. Petersburg University. The following year he transferred to the Tiflis Botanical Garden, where he organized a laboratory of plant physiology.

Maksimov moved to Leningrad in 1921 and began to work in the main botanical garden of the Academy of Sciences of the U.S.S.R., where he organized a laboratory of experimental plant ecology, which he directed until 1927. From 1925 to 1933 he was also director of the laboratory of plant physiology which he organized in the All-Union Research Institute of Plant Growing. At the same time (1922–1931) he carried out major work in teaching and management of the department of botany at the A. I. Herzen Pedagogical Institute in Leningrad. From 1933 to 1939 Maksimov was in Saratov, at the All-Union Institute of Grain Economy, where he headed the section of plant physiology, and at Saratov University, in the department of plant physiology (1935–1939). In 1936 Maksimov began his work at the Institute of Plant Physiology of the Soviet Academy of Sciences, first as manager of the laboratory for growth and development of plants and, from 1939, as director of the institute. His teaching continued as part of his duties as head of the department of plant physiology of the Timiryazev Agricultural Academy in Moscow (1943–1951).

Maksimov’s basic scientific research was connected with the study of frost resistance and drought resistance of plants. He was one of the most important pioneers in the study of the ecological physiology of plants. Maksimov’s scientific work began with the study of respiration in fungi and the influence of injury on the respiration coefficient. His results were stated in the article “K voprosu o dykhanii” (“On the Question of Respiration”; 1904), one of the first investigations in which the fermentative nature of respiration was established. In a later study of the respiration of woody plants during the winter, Maksimov became interested in why coniferous needles and winter buds do not die at low temperatures which other plants cannot endure. Studying cold resistance, he spoke against the current idea that this property does not depend on the external environment but is defined only by the plant’s inner qualities. Maksimov considered that the damage to or killing of the plant at low temperatures was caused by the formation and accumulation of ice crystals between the cells, which dehydrate and mechanically damage the protoplasm, leading to the coagulation of plasma colloids. He showed that the resistance of the cell to low temperatures can be increased by the use of sugar and mineral salts and by an increase in the cell juice of the amount of other osmotically active substances that decrease the quantity of ice crystals formed. Thus he formulated the first theory of the “chemical defense of the plant against death by frost,” which he presented in his master’s thesis.

In 1914 Maksimov began a new and more fruitful stage of research—the study of the water system and drought resistance of plants. His first experiments showed that xerophyte plants with enough water supply transpire no less moisture than mesophytes and demonstrated the inadequacy of Schimper’s then widely recognized theory. This theory explained the drought resistance of xerophytes as an ability to use water economically because of certain peculiarities in their anatomical-morphological structure that supposedly result in a level of transpiration much curtailed in comparison with that of mesophytes. Maksimov suggested that the basis of drought resistance of xerophytes lies not in their structure but in the biochemical capacity of their protoplasm to bear a prolonged water shortage without harmful consequences. He saw the plant’s capacity to sustain prolonged dehydration as a complex of the traits characterizing xerophytes: the peculiarities of their protoplasm, its specific structure at a comparatively high osmotic pressure, and the anatomical-morphological peculiarities of the plant’s structure. Maksimov also recognized the variety of adaptations to the conditions of existence in various ecological groups of xerophytes, explaining their origin in nature from an evolutionary position. His works on the water system and drought resistance of plants laid the foundation for a new area in botany —the ecological physiology of plants.

Maksimov also conducted research on photosynthesis, growth, development, photoperiodism, and the natural and artificial stimulators of plant growth. All these investigations were carried out under laboratory conditions and also in a natural situation for wild plants and in the field for cultivated plants. Taken as a whole, this work had great significance for the theory as well as the practice of agriculture: Maksimov developed a series of recommendations for obtaining higher yields in arid regions and in hothouses by the creation of a new regimen of artificial light, for directing the growth and development of plants by means of photoperiodic effects, and for rooting cuttings of cultivated and wild plants under the influence of growth activators.

Besides his research, Maksimov paid much attention to scientific organization and set up laboratories of plant physiology in several institutions. He also devoted a substantial part of his time to teaching. His Kratkykurs fiziologii rasteny (“Short Course in Plant Physiology”), which went through nine editions between 1927 and 1958, greatly influenced the development of plant physiology in the Soviet Union. The seventh edition of this text was awarded the K. A. Timiryazev Prize in 1944. Maksimov also wrote Vvedenie v botaniku (“Introduction to Botany”; 1915), which went through two editions; a popular book, Ot chego byvayut zusukhi i mozhno li s nimi borotsya (“What Causes Droughts and How We Can Fight Them”; 1951); and Kak zhivet rastenie (“How a Plant Lives”; 1951). He also published about 250 scientific articles and notes.

For his teaching and research work in scientific organizations Maksimov was elected a corresponding member (1939) and an academician (1946) of the Academy of Sciences of the U.S.S.R. In 1945 he received the Order of the Red Banner of Labor and was elected a vice-president of the All-Union Botanical Society, of which he became an honorary member in 1947. Maksimov was also a corresponding member of the Czechoslovakian Agricultural Academy (1934) and a corresponding member of the Royal Netherlands Botanical Society (1936).

BIBLIOGRAPHY

I. Original Works. Maksimov’s writings include “O vymerzanii i kholodostoykosti rasteny. Eksperimentalnye i kriticheskie issledovania” (“On the Frost Resistance and Cold Resistance of Plants. Experimental and Critical Research”), in Izvestiya Lesnogo instituta, no. 25 (1913), 1–330, his master’s diss.; “Zasukhoustoychivost rasteny s fiziologicheskoy tochki zrenia” (“Drought Resistance of Plants From the Physiological Point of View”), in Zhurnal opytnoi agronomii, 22 (1921–1923), 173–186; “Znachenie v zhizni rastenia sootnoshenia mezhdu prodolzhitelnostyu dnya i nochi (fotoperiodizm)” (“The Significance of the Relation Between the Length of Day and of Night in the Life of the Plant [Photoperiodism]”), in Trudy po prikladnoi botanike, genetike i selektsii, 14 , no. 5 (1924–1925), 65–90; Fiziologicheskie osnovy zasukhoustoychivosti rasteny (“Physiological Bases of Drought Resistance in Plant”; Leningrad, 1936); “Rostovye veshchestva, priroda ikh deystvia i prakticheskoe primenenie” (“Growth Substances, the Nature of Their Effects and Practical Application”), in Uspekhi sovremennoi biologii, 22 , no. 2 (1946), 161–180; and Izbrannye raboty po zasukhoustoychivosti i zimostoykosti rasteny (“Selected Words in Drought Resistance and Winter Resistancec of plants”), 2 vols. (Moscow, 1952).

II. Secondary Literature. See P. A. Genkel, “Nauchnaya deyatelnot Nikolaya Aleksandrovicha Maksimova i ego rol v sozdanii ekologicheskoy fiziologii rasteny” (“The Scientific Career of N. A. Maksimov and His Role in the Creation of the Ecological Physiology of Plants”), in Problemy fiziologii rasteny. Istoricheskie ocheskie ocherki (“Problems of Plant Physiology. Historical Sketches”; Moscow, 1969), pp. 306–331, literature about Maksimov on p. 326; Nikolay Aleksandrovich Maksimov, materialy k biobibliografii uchenykh SSSR Ser. biol. nauk, fiziol. rast. (“Materials for a Biobibliography of Soviet Scientists, Biological Science Series, plant physiology”), no. 2 (Moscow-Leningrad, 1949), with intro. article by P. A. Genkel and bibliography of Maksimov’s works and literature on him compiled by O. V. Isakova; and I. I. Tumanov, “Osnovnye cherty nauchnoy deyatelnosti N. A. Maksimova” (“Basic Outlines of the Scientific Work of N. A. Maksimov”), in Pamyate akademika N. A. Malsimova (“Recollections of Academician N. A. Maksimov”; Moscow, 1957), pp. 3–9.

E. M. Senchenkova