Daniel Israel Arnon (November 14, 1910 – December 20, 1994) was a Polish-born American

plant physiologist Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Plant physiologists study fundamental processes of plants, such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropi ...

and

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral science, behavior ...

recipient whose research led to greater insights into the operation of

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

and

nutrition Nutrition is the biochemistry, biochemical and physiology, physiological process by which an organism uses food and water to support its life. The intake of these substances provides organisms with nutrients (divided into Macronutrient, macro- ...

plants Plants are the eukaryotes that form the kingdom Plantae; they are predominantly photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with cyanobacteria to produce sugars f ...

. In the first part of his professional career, the so-called "Plant Nutrition Years (1936-1950)", Arnon and collaborators discovered the essentiality of

molybdenum Molybdenum is a chemical element; it has Symbol (chemistry), symbol Mo (from Neo-Latin ''molybdaenum'') and atomic number 42. The name derived from Ancient Greek ', meaning lead, since its ores were confused with lead ores. Molybdenum minerals hav ...

for the growth of all plants and of

vanadium Vanadium is a chemical element; it has Symbol (chemistry), symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an ...

for the growth of

green algae The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ...

. In the second one, the so-called "Photosynthesis Period (1951-1978)", plant

micronutrient Micronutrients are essential chemicals required by organisms in small quantities to perform various biogeochemical processes and regulate physiological functions of cells and organs. By enabling these processes, micronutrients support the heal ...

work led him to photosynthesis. In 1954, Arnon,

Mary Belle Allen Mary Belle Allen (November 11, 1922, Morristown, New Jersey –1973, Fairbanks, Alaska) was an American botanist, chemist, mycologist, algologist, and plant pathologist, and a pioneer of biochemical microbiology. With Daniel I. Arnon and F ...

and

Frederick Robert Whatley Frederick Robert Whatley FRS (26 January 1924 – 14 November 2020) was an English botanist and biochemist who held the title of Sherardian Professor of Botany at the University of Oxford from 1971 to 1991. In 1954, Whatley, Mary Belle Allen a ...

discovered

photophosphorylation In the process of photosynthesis, the phosphorylation of ADP to form ATP using the energy of sunlight is called photophosphorylation. Cyclic photophosphorylation occurs in both aerobic and anaerobic conditions, driven by the main primary source of ...

''in vitro''. In 1967, for this work, he was nominated jointly with Allen and Whatley for a

Nobel Prize in Chemistry The Nobel Prize in Chemistry () is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outst ...

Early life and education

Arnon was born on November 14, 1910, in

Warsaw, Poland Warsaw, officially the Capital City of Warsaw, is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland. Its population is officially estimated at 1.86 million residents within a grea ...

, to a Jewish family. Summers spent on the family's farm helped foster Arnon's interest in agriculture. His father had lost the family's food wholesale business after

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

. Reading about scientific agriculture in the works of

Jack London John Griffith London (; January 12, 1876 – November 22, 1916), better known as Jack London, was an American novelist, journalist and activist. A pioneer of commercial fiction and American magazines, he was one of the first American authors t ...

, led him to save his money and apply to the

University of California The University of California (UC) is a public university, public Land-grant university, land-grant research university, research university system in the U.S. state of California. Headquartered in Oakland, California, Oakland, the system is co ...

in the United States of America.

Career

Arnon enrolled as a student in the University of California from Poland, and would spend his entire professional career at the university, until his retirement in 1978. He earned his Bachelor's degree in 1932 and his Ph.D. in plant physiology in 1936 at UC Berkeley under the supervision of Dennis R. Hoagland. Some of Arnon's earliest research focused on growing plants in nutrient-enriched water rather than

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

. Together with his supervisor, he further developed the

Hoagland solution Hoagland is an American surname derived from the Dutch surname Hoogland (surname), Hoogland () or the Swedish Högland. The earliest immigrants were Dirks Jansz Hoogland, from Maarsseveen, and Christoffel Hoogland, from Haarlem, who settled in New A ...

which was published in modified form as Hoagland's solution (1, 2) in 1938. After Hoagland's death, it was further revised by Arnon in 1950. Arnon became an assistant professor at the University of California in 1941. During

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, Arnon served as a major in the Army Air Corps of the

United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

and was sent to the Pacific Theater of Operations. From 1943 to 1946 he used his prior experience with plant nutrition on

Ponape Island Pohnpei (formerly known as Ponape or Ascension, from Pohnpeian language, Pohnpeian: "upon (''pohn'') a stone altar (''pei'')") is an island of the Senyavin Islands which are part of the larger Caroline Islands group. It belongs to Pohnpei Stat ...

, where there was no

arable land Arable land (from the , "able to be ploughed") is any land capable of being ploughed and used to grow crops.''Oxford English Dictionary'', "arable, ''adj''. and ''n.''" Oxford University Press (Oxford), 2013. Alternatively, for the purposes of a ...

available. He was able to grow food to feed the troops stationed there using gravel and nutrient-enriched water. After returning from military service in 1946, Arnon became an associate professor of

cell physiology Cell physiology is the biological study of the activities that take place in a cell to keep it alive. The term ''physiology'' refers to normal functions in a living organism. Animal cells, plant cells and microorganism cells show similarities in ...

at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

. He investigated

plant nutrition Plant nutrition is the study of the chemical elements and compounds necessary for plant growth and reproduction, plant metabolism and their external supply. In its absence the plant is unable to complete a normal life cycle, or that the element i ...

and the contributions of

micronutrients Micronutrients are essential chemicals required by organisms in small quantities to perform various biogeochemical processes and regulate physiological functions of cells and organs. By enabling these processes, micronutrients support the heal ...

such as

for the growth of all plants and of

for the growth of

. In the 1950s, Arnon performed research with

and F. Robert Whatley on

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

s and their role in

, identifying a process which they named " photosynthetic phosphorylation". The group demonstrated how energy from sunlight is used to form

adenosine triphosphate Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides energy to drive and support many processes in living cell (biology), cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known ...

, the energy transport messenger within living cells, by adding a third phosphorus group to

adenosine diphosphate Adenosine diphosphate (ADP), also known as adenosine pyrophosphate (APP), is an important organic compound in metabolism and is essential to the flow of energy in living cells. ADP consists of three important structural components: a sugar backbon ...

. In 1954, they reproduced the process in a laboratory, making them the first to successfully demonstrate the chemical function of photosynthesis, producing sugar and starch from inputs of carbon dioxide and water ''in vitro''. Arnon served as president of the

American Society of Plant Physiologists The American Society of Plant Biologists (ASPB) is a non-profit professional society for research and education in plant science with over 4,000 members world-wide. It was founded in 1924, as the American Society of Plant Physiologists (ASPP). Th ...

from 1952 to 1953. Arnon served as the

editor Editing is the process of selecting and preparing written, visual, audible, or cinematic material used by a person or an entity to convey a message or information. The editing process can involve correction, condensation, organization, a ...

of the ''Annual Review of Plant Physiology'' (now the ''

Annual Review of Plant Biology ''Annual Review of Plant Biology'' is a peer-reviewed scientific journal published by Annual Reviews. It was first published in 1950 as the ''Annual Review of Plant Physiology''. Sabeeha Merchant has been the editor since 2005, making her the lo ...

'') for 1956.

Awards

In 1940, together with Dennis Hoagland, Arnon received the AAAS

Newcomb Cleveland Prize The Newcomb Cleveland Prize of the American Association for the Advancement of Science (AAAS) is annually awarded to author(s) of outstanding scientific paper published in the Research Articles or Reports sections of ''Science Science is a ...

for the work "Availability of Nutrients with Special Reference to Physiological Aspects". In 1961, Arnon was elected to the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

, in 1962 to the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

, and in 1974 to the Leopoldina. In 1966, he received the

Stephen Hales Stephen Hales (17 September 16774 January 1761) was an English clergyman who made major contributions to a range of scientific fields including botany, pneumatic chemistry and physiology. He was the first person to measure blood pressure. He al ...

Prize, and in 1967, he was nominated jointly with

and

for a

. In 1973, he was awarded the

for "his fundamental research into the mechanism of green plant utilization of light to produce chemical energy and oxygen and for contributions to our understanding of plant nutrition." The Arnon Lecture has been held annually at UC Berkeley since 2000 in early March in honour of the late Professor Daniel I. Arnon. Speakers have made significant contributions to photosynthesis or a related field and are selected by the ''Arnon Lecture Committee''.

Family

A resident of

Kensington, California Kensington is an Unincorporated area, unincorporated community and census designated place located in the Berkeley Hills, in the East Bay (San Francisco Bay Area), East Bay, part of the San Francisco Bay Area, in Contra Costa County, Californi ...

, Arnon died at age 84 on December 20, 1994, in

Berkeley, California Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Anglo-Irish bishop and philosopher George Berkeley. It borders the cities of Oakland, Cali ...

, of complications resulting from

cardiac arrest Cardiac arrest (also known as sudden cardiac arrest CA is when the heart suddenly and unexpectedly stops beating. When the heart stops beating, blood cannot properly Circulatory system, circulate around the body and the blood flow to the ...

. He had three daughters and two sons. His wife, the former Lucile Soulé, died in 1986.

References

External links

National Academy of Sciences Biographical MemoirChemistry Tree - Daniel I. Arnon
{{DEFAULTSORT:Arnon, Daniel I 1910 births 1994 deaths National Medal of Science laureates People from Kensington, California Researchers of photosynthesis UC Berkeley College of Natural Resources alumni University of California, Berkeley College of Letters and Science faculty Fellows of the American Academy of Arts and Sciences Plant physiologists 20th-century American botanists Jewish American scientists Polish emigrants to the United States United States Army personnel of World War II Annual Reviews (publisher) editors 20th-century American Jews Members of the Royal Swedish Academy of Sciences