Sharon R. Long
Encyclopedia
Sharon R. Long, Ph.D. is an American plant biologist
, and a professor in the Department of Biological Sciences at Stanford University
, and director of the Long Lab.
, Caltech (B.S.) and Yale
(Ph.D.) in biochemistry and genetics, and began her research on plants and symbiosis while a postdoc at Harvard University
. She is a member of the National Academy of Sciences
, and a 1992 MacArthur Fellows Program
recipient. She joined the Stanford faculty in 1982, where she holds the Steere-Pfizer chair in Biological Sciences, and from 1994-2001 she was an Investigator of the Howard Hughes Medical Institute
. She served as Dean of Humanities and Sciences
at Stanford University
from 2001 to 2007. In September 2008 she was identified as one of 5 science advisors for Democratic presidential candidate Barack Obama.
between Sinorhizobium meliloti
and its host plants in the genus Medicago
. Rhizobium cells recognize and form nodules on their plant hosts. Her group discovered that a flavone (luteolin
) derived from alfalfa
seed extracts is necessary for activation of nodulation
genes (nod ABC) in Sinorhizobium meliloti
. They proved that some nod genes encode enzymes that synthesize Nod Factor. They discovered that plant root hair cells show rapid ionic changes including calcium spiking in response to specific Nod Factors. With colleagues, they have identified plant genes for symbiosis, and correlated these with specific stages in nodule development.
Biologist
A biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...
, and a professor in the Department of Biological Sciences at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
, and director of the Long Lab.
Education and career
She studied at Harvey Mudd CollegeHarvey Mudd College
Harvey Mudd College is a private residential liberal arts college of science, engineering, and mathematics, located in Claremont, California. It is one of the institutions of the contiguous Claremont Colleges, which share adjoining campus grounds....
, Caltech (B.S.) and Yale
YALE
RapidMiner, formerly YALE , is an environment for machine learning, data mining, text mining, predictive analytics, and business analytics. It is used for research, education, training, rapid prototyping, application development, and industrial applications...
(Ph.D.) in biochemistry and genetics, and began her research on plants and symbiosis while a postdoc at Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
. She is a member of the National Academy of Sciences
United States National Academy of Sciences
The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...
, and a 1992 MacArthur Fellows Program
MacArthur Fellows Program
The MacArthur Fellows Program or MacArthur Fellowship is an award given by the John D. and Catherine T...
recipient. She joined the Stanford faculty in 1982, where she holds the Steere-Pfizer chair in Biological Sciences, and from 1994-2001 she was an Investigator of the Howard Hughes Medical Institute
Howard Hughes Medical Institute
Howard Hughes Medical Institute is a United States non-profit medical research organization based in Chevy Chase, Maryland. It was founded by the American businessman Howard Hughes in 1953. It is one of the largest private funding organizations for biological and medical research in the United...
. She served as Dean of Humanities and Sciences
Stanford University School of Humanities and Sciences
The Stanford University School of Humanities and Sciences is the heart of the undergraduate program and grants the majority of Stanford University's degrees. The School has 28 departments and 20 interdisciplinary degree-granting programs...
at Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
from 2001 to 2007. In September 2008 she was identified as one of 5 science advisors for Democratic presidential candidate Barack Obama.
Research
Her current research uses molecular, genetic, and biochemical techniques to study the early stages of symbiosisSymbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
between Sinorhizobium meliloti
Sinorhizobium meliloti
Sinorhizobium meliloti is a Gram-negative nitrogen-fixing bacterium . It forms a symbiotic relationship with legumes from the genera Medicago, Melilotus and Trigonella, including the model legume Medicago truncatula. This symbiosis results in a new plant organ termed a root nodule. The S...
and its host plants in the genus Medicago
Medicago
Medicago is a genus of flowering plants, commonly known as medick or burclover. The name is based on Latin medica 'alfalfa, lucerne,' from 'Median .'...
. Rhizobium cells recognize and form nodules on their plant hosts. Her group discovered that a flavone (luteolin
Luteolin
Luteolin is a yellow crystalline compound. It is a flavonoid; to be specific, it is one of the more common flavones. From preliminary research, it is thought to play a role in the human body possibly as an antioxidant, a free radical scavenger, a promoter of carbohydrate metabolism, or an immune...
) derived from alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
seed extracts is necessary for activation of nodulation
Root nodule
Root nodules occur on the roots of plants that associate with symbiotic nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia...
genes (nod ABC) in Sinorhizobium meliloti
Sinorhizobium meliloti
Sinorhizobium meliloti is a Gram-negative nitrogen-fixing bacterium . It forms a symbiotic relationship with legumes from the genera Medicago, Melilotus and Trigonella, including the model legume Medicago truncatula. This symbiosis results in a new plant organ termed a root nodule. The S...
. They proved that some nod genes encode enzymes that synthesize Nod Factor. They discovered that plant root hair cells show rapid ionic changes including calcium spiking in response to specific Nod Factors. With colleagues, they have identified plant genes for symbiosis, and correlated these with specific stages in nodule development.
Selected publications
- N.K. Peters, J. Frost and S.R. Long (1986) A flavone, luteolin, induces expression of Rhizobium meliloti nodulation genes. Science: 977-980.
- S.R. Long (1989) The Rhizobium-legume symbiosis: life together in the underground. Cell 56: 203-214.
- J. Schwedock and S. R. Long (1990) ATP sulfurylase activity of the nodP and nodQ gene products of Rhizobium meliloti. Nature 348: 644-647.