Researchers Find an Essential Gene for Forming Ears of CornSeptember 25, 2008Cold Spring Harbor, NY - Cold Spring Harbor Laboratory (CSHL) professor David Jackson, Ph.D., and a team of plant geneticists have identified a gene essential in controlling development of the maize plant, commonly known in the United States as corn. The new research extends the growing biological understanding of how the different parts of maize arise--important information for a plant that is the most widely planted crop in the U.S. and a mainstay of the global food supply. The researchers found that a gene called sparse inflorescence1, or spi1, is involved the maize plant's synthesis of the growth hormone auxin. This chemical messenger is familiar to biology students, who learn that it is produced by the tip of a growing shoot. When the hormone is applied to only one side of the shoot, that side grows faster, causing the tip to bend. In a much more complex process, auxin also helps to shape structures such as leaves or the female organs (ears) and male organs (tassels) of corn. The initial stages of these structures are called meristems, which consist of versatile, undifferentiated cells analogous to the stem cells found in animals. Jackson and colleagues from UC San Diego, including Andrea Gallavotti who spent one year in Jackson's lab to perform some of this work, and at California State University at Long Beach and Pennsylvania State University, found that meristems emerge from an interplay between the synthesis of auxin by various cells and its motion between them. Disrupting either its production (by causing a mutation in the spi1 gene) or its motion results in stunted, defective organs. Eudicots vs. Monocots Much has been learned in the past about organ development in the cress plant known as Arabidopsis, which biologists regard as a "model organism" for plant research, much as the lab mouse has served as a model for research on mammalian biology. Arabidopsis is in a plant group called eudicots, however, while maize and many other food crops belong to a group known as monocots. The spi1 gene has cousins that affect auxin synthesis and organ formation in Arabidopsis, but there are important differences. "In maize, spi1 mutations cause severe developmental effects, which is not the case in Arabidopsis, which we demonstrated by deleting, or 'knocking-out,' genes similar to spi1," Jackson explained. "Our work helped demonstrate that spi1 in maize has evolved a dominant role in auxin biosynthesis, and is essential for what we plant scientists call inflorescence development--the process in seed plants in which a shoot forms that supports the plant's flowers," he added. "When we looked at the interaction between spi1 and genes of the plant that regulate auxin transport, we found, interestingly, that the transport of auxin and biosynthesis work together in a synergistic manner to regulate how the meristem and lateral organs of the maize plant develop." "sparse inflorescence1 encodes a monocot-specific YUCCA-like gene required for vegetative and reproductive development in maize" received advanced online publication in the Proceedings of the National Academy of Sciences on September 17, 2008. The complete author list is: Andrea Gallavotti, Solmaz Barazesh, Simon Malcomber, Darren Hall, David Jackson, Robert Schmidt, and Paula McSteen. The paper is available at http://dx.doi.org/10.1073/pnas.0805596105. Cold Spring Harbor Laboratory (CSHL) is a private, not-for-profit research and education institution at the forefront of efforts in molecular biology and genetics to generate knowledge that will yield better diagnostics and treatments for cancer, neurological diseases and other major causes of human suffering. Cold Spring Harbor Laboratory |
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| Related Maize Current Events and Maize News Articles Scientists at UA, collaborating institutions decode maize genome Scientists from the University of Arizona led by Arizona Genomics Institute director Rod A. Wing and from collaborating institutions have deciphered the complete genetic code of the maize plant for the first time. Scientists unlock clues for tailoring corn plant for food, energy needs Scientists have long known that the offspring of two inbred strains tend to be superior to both their parents. Now, a team of researchers including a University of Florida geneticist has discovered clues to why that might be the case for one of the most important crops in the world: corn. Maize cell wall genes identified, giving boost to biofuel research Purdue University scientists have helped identify and group the genes thought to be responsible for cell wall development in maize, an effort that expands their ability to discover ways to produce the biomass best suited for biofuels production. New map of variation in maize genetics holds promise for developing new varieties A new study of maize has identified thousands of diverse genes in genetically inaccessible portions of the genome. New techniques may allow breeders and researchers to use this genetic variation to identify desirable traits and create new varieties that were not easily possible before. New Maize Map to Aid Plant Breeding Efforts In a massive survey of genetic diversity in maize, also known as corn, researchers across the United States, have developed a gene map that should pave the way to significant improvements in a plant that is a major source of food, fuel, animal feed and fiber around the world. DNA barcodes: Creative new uses span health, fraud, smuggling, history, more The scientific ability to quickly and accurately identify species through DNA "barcoding" is being embraced and applied by a growing legion of global authorities - from medical and agricultural researchers to police and customs authorities to palaeontologists and others. Wild pigs and deer do not spread GM corn via feces or accumulate transgenic residues in meat Deer stew, roast of wild boar, venison ragout - come fall, all varieties of game are in season for gourmets. However, ever since the worldwide surge in genetically modified corn, critical consumers' appetites have abated somewhat. UCR researchers develop genetic map for cowpea, accelerating development of new varieties Cowpea, a protein-rich legume crop, is immensely important in many parts of the world, particularly drought-prone regions of Africa and Asia, where it plays a central role in the diet and economy of hundreds of millions of people. The amazing maze of maize evolution Understanding the evolution and domestication of maize has been a holy grail for many researchers. As one of the most important crops worldwide and as a crop that appears very different from its wild relatives as a result of domestication, understanding exactly how maize has evolved has many practical benefits and may help to improve crop yields. UGA researchers propose model for disorders caused by improper transmission of chromosomes Parents of healthy newborns often remark on the miracle of life. The joining of egg and sperm to create such delightful creatures can seem dazzlingly beautiful if the chromosome information from each parent has been translated properly into the embryo and newborn. More Maize Current Events and Maize News Articles |
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