Brassinosteroids are polyhydroxylated steroids. The most active compound is Brassinolide (BL). Since the discovery of BL, more than 70 natural analogs, collectively called brassinosteroids (BRs), have been isolated and characterized. Exogenous application of BRs to plants at nanomolar to micromolar concentrations has a wide spectrum of physiological effects, including promotion of cell elongation and division, enhancement of tracheary element differentiation, retardation of abscission, enhancement of gravitropic-induced bending, promotion of ethylene biosynthesis, and enhancement of stress resistance. A number of BR-deficient mutants have been discovered in Arabidopsis, pea, and tomato. These mutants exhibit dwarfism when grown in either light or dark conditions. Many of these mutants also have dark-green leaves, reduced fertility, a prolonged lifespan, and abnormal skotomorphogenesis. They are synthesized from campesterol via the mevalonate pathway. The biosynthetic pathway was elucidated in cultured cells of Catharanthus roseus by Japanese researchers, and then confirmed in Arabidopsis mutants. The major biosynthesis pathway in Arabidopsis is shown here .
When D'Arcy Wentworth Thompson’s On Growth and Form was published 100 years ago, it raised the question of how biological forms arise during development and across evolution. In light of the advances in molecular and cellular biology since then, a succinct modern view of the question states: how do genes encode geometry? Our new special issue is packed with articles that use mathematical and physical approaches to gain insights into cell and tissue patterning, morphogenesis and dynamics, and that provide a physical framework to capture these processes operating across scales.
Michael M. Neff, .
Dr. Neff grew up on the East Coast in Baltimore, Maryland where he attended the Friends (Quaker) school for his K-12 education. He moved to Colorado Springs in 1981 and was a biology major focusing on ecology at the Colorado College. At the same time, his parents moved to Seattle, Washington. Visits to the Northwest convinced Dr. Neff to move further west where he became more interested in bench-related research. It was while working in a virology lab at the University of Washington that he met his wife, Sandy O’Keefe. A fascination with plants led Dr. Neff to pursue a . degree in Botany at the University of Washington. After working as a lab technician in a yeast genetics lab with Dr. Trisha Davis, Dr. Neff rejoined the University of Washington Department of Botany to pursue his ., studying plant physiology with Dr. Elizabeth Van Volkenburgh. After graduating in 1995, Dr. Neff was a NIH postdoctoral fellow studying plant molecular genetics with Dr. Joanne Chory at the Salk Institute for Biological Studies in La Jolla California. He was a faculty member in the Department of Biology at Washington University in St. Louis, Missouri from 1999 to 2007 before accepting the new Crop Biotechnology faculty position in the Department of Crop and Soil Sciences at Washington State University.