Daniel Israel Arnon (November 14, 1910 – December 20, 1994) was a Polish-born American plant physiologist 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 and social scienc ...

recipient whose research led to greater insights into the operation of

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in ...

and

nutrition Nutrition is the biochemical and physiological process by which an organism uses food to support its life. It provides organisms with nutrients, which can be metabolized to create energy and chemical structures. Failure to obtain sufficient ...

plants Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclude ...

. 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 with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with lead ...

for the growth of all plants and of

vanadium Vanadium is a chemical element with the 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 oxide layer ( pass ...

for the growth of

green algae The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga ...

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

micronutrient Micronutrients are essential dietary elements required by organisms in varying quantities throughout life to orchestrate a range of physiological functions to maintain health. Micronutrient requirements differ between organisms; for example, huma ...

work led him to photosynthesis. In 1954, Arnon, Mary Belle Allen and Frederick Robert Whatley 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 he was nominated jointly (but unsuccessfully) with Allen and Whatley for a

Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...

Early life and education

Arnon was born on November 14, 1910, in

Warsaw, Poland Warsaw ( pl, Warszawa, ), officially the Capital City of Warsaw,, abbreviation: ''m.st. Warszawa'' is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland, and its population is officiall ...

, 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 (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

. Reading about scientific agriculture in the works of

Jack London John Griffith Chaney (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 to ...

, led him to save his money and apply to the

University of California The University of California (UC) is a public land-grant research university system in the U.S. state of California. The system is composed of the campuses at Berkeley, Davis, University of California, Irvine, Irvine, University of Califor ...

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 or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

. Together with his supervisor, he further developed the

Hoagland solution The Hoagland solution is a hydroponic nutrient solution that was newly developed by Hoagland and Snyder in 1933, modified by Hoagland and Arnon in 1938, and revised by Arnon in 1950. It is one of the most popular artificial solution compositions ...

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, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

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

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, ...

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 "upon (''pohn'') a stone altar (''pei'')" (formerly known as Ponape or Ascension, Proto-Chuukic-Pohnpeic: ''*Fawo ni pei)'' is an island of the Senyavin Islands which are part of the larger Caroline Islands group. It belongs to Pohnpei ...

, where there was no

arable land Arable land (from the la, arabilis, "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 th ...

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 (biology), cell to keep it alive. The term ''physiology'' refers to normal functions in a living organism. Animal cells, plant cells and microorganism cells show si ...

at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant un ...

. 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 dietary elements required by organisms in varying quantities throughout life to orchestrate a range of physiological functions to maintain health. Micronutrient requirements differ between organisms; for example, huma ...

such as

for the growth of all plants and of

for the growth of

. In the 1950s, Arnon performed research with Mary Belle Allen and F. Robert Whatley on

chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it i ...

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 an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms ...

, 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 backbone ...

. 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 American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

from 1952 to 1953. Arnon served as the

editor Editing is the process of selecting and preparing written, photographic, 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, or ...

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 1961, Arnon was elected to the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, 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 Nat ...

, in 1962 to the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) 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, a ...

, and in 1974 to the Leopoldina. 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." In 1940, together with Dennis Hoagland, he 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''. Established in 192 ...

for the work "Availability of Nutrients with Special Reference to Physiological Aspects". 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 community and census designated place located in the Berkeley Hills, in the East Bay, part of the San Francisco Bay Area, in Contra Costa County, California. In the 20th century it was considered part of Berkeley ...

, 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 Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and E ...

, of complications resulting from

cardiac arrest Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possi ...

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

References

External links

National Academy of Sciences Biographical Memoir
{{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