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 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. Domestication of Capsicum annuum chile pepper provides insights into crop origin and evolution Without the process of domestication, humans would still be hunters and gatherers, and modern civilization would look very different. New study finds that sharing genetic resources key to adaptation to climate change in Africa As rapidly rising temperatures in Africa threaten to scorch local varieties of maize and other food staples, the food security of many Africans will depend on farmers in one country gaining access to climatically suitable varieties now being cultivated in other African nations, and beyond. Crop Models Help Increase Yield per Unit of Water Used Crop water use efficiency (WUE, or yield per unit of water used), also known as crop water productivity, can be improved through irrigation management and methods, including deficit irrigation (irrigating less than is required for maximum yields) and supplemental irrigation (irrigating to supplement precipitation so as to avoid crop failure or severe yield decline). Wild grass became maize crop more than 8,700 years ago The earliest physical evidence for domesticated maize, what some cultures call corn, dates to at least 8,700 calendar years ago, and it was probably domesticated by indigenous peoples in the lowland areas of southwestern Mexico, not the highland areas. Teeth of Columbus' crew flesh out tale of new world discovery The adage that dead men tell no tales has long been disproved by archaeology. 200,000 rice mutants available worldwide for scientific investigation Scientists across the world are building an extensive repository of genetically modified rice plants in the hope of understanding the function of the approximately 57,000 genes that make up the genome of Oryza sativa. More Maize Current Events and Maize News Articles |
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