Sharon Rugel Long (born March 2, 1951) is an American plant biologist. She is the Steere-Pfizer Professor of Biological Science in the Department of Biology at Stanford University, and the Principal Investigator of the Long Laboratory at Stanford.[1][2]
Long joined the Stanford University faculty in 1982[10] as an assistant professor, rising to associate professor in 1987, and full professor in 1992.[11]
From 1994 to 2001, she was also an Investigator of the Howard Hughes Medical Institute.[12][11]
She currently holds the Steere-Pfizer chair in Biological Sciences at Stanford.[1] She serves on the Board of Directors of Annual Reviews.[13]
In September 2008 she was identified as one of 5 science advisors for Democratic presidential candidate Barack Obama.[17][18] In 2011, she was appointed to the President's Committee on the National Medal of Science by President Obama.[3]
Long identified and cloned genes that allow bacteria to find and enter certain plants in which they live symbiotically. She has examined the interactions of Rhizobium bacteria with legumes such as alfalfa, soybeans and peas, in which they enhance nitrogen production. She has genetically modified bacteria to make them more effective at entering host plants and producing nitrogen. Such initiatives may enable farmers to reduce nitrogen fertilizer use and runoff of fertilizer into local water supplies.[11]
Her current[when?] research uses molecular, genetic, and biochemical techniques to study the early stages of symbiosis between Sinorhizobium meliloti and its host plants in the genus Medicago.[19]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.[20] 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.[21][22][23][24][25]
^Long, Sharon R.; Buikema, William J.; Ausubel, Frederick M. (29 July 1982). "Cloning of Rhizobium meliloti nodulation genes by direct complementation of Nod− mutants". Nature. 298 (5873): 485–488. Bibcode:1982Natur.298..485L. doi:10.1038/298485a0. S2CID24556846.
^ abcdeBailey, Martha J. (1998). American women in science, 1950 to the present: a biographical dictionary. Santa Barbara, California: ABC-Clio. p. 240. ISBN978-0-87436-921-2.
