6 February 2003

NON-GE PLANT BREEDING STARVED TO DEATH / JUMPING GENES

"More than half of CIMMYT's fields in Obregón lie fallow, and the trainee plant breeders are staying at home. CIMMYT is not alone. All over the world, conventional plant breeding has fallen on hard times, and is seen as the unfashionable older cousin of genetic engineering. "Plant breeding is getting dumped along the wayside for not being sexy enough," claims Greg Traxler, an agricultural economist at Auburn University in Alabama." - article in Nature

all items via Agnet;
1.CROP IMPROVEMENT: A DYING BREED - Nature
2.GM CROPS STILL A CONCERN
3.JUMPING GENES SEEN IN GM PLANT EXPERIMENT
4.JUMPING GENES LIVEN GM DEBATE
5.DIRECT MEASUREMENT OF TRANSFER RATE OF CHLOROPLAST DNA INTO NUCLEUS - Nature

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1.CROP IMPROVEMENT: A DYING BREED

February 6, 2003
Nature 421, 568 - 570 (2003)
Jonathan Knight

Public-sector research into classical crop breeding is, according to this story, withering, supplanted by 'sexier' high-tech methods.  But without breeders' expertise, molecular-genetic approaches might never bear fruit.

Normally, at this time of year, agricultural scientists from around the world would be converging on the headquarters of the International Maize and Wheat Improvement Center, known as CIMMYT, in Texcoco, near Mexico City.

They would then travel together to a desert field station near Ciudad Obregón in northwestern Mexico to study the current crop of experimental wheat cultivars, planted at the beginning of winter.

But not this year. For the first time in half a century, the research centre that helped to sow the seeds of the 'green revolution' of the 1960s and '70s has been forced to skip a cycle of wheat breeding trials, because of a lack of money. More than half of CIMMYT's fields in Obregón lie fallow, and the trainee plant breeders are staying at home.

CIMMYT is not alone. All over the world, conventional plant breeding has fallen on hard times, and is seen as the unfashionable older cousin of genetic engineering. "Plant breeding is getting dumped along the wayside for not being sexy enough," claims Greg Traxler, an agricultural economist at Auburn University in Alabama. Government funding of plant-breeding research has all but dried up in the United States and Europe, and the World Bank and donor nations have recently slashed their support for the Consultative Group on International Agricultural Research (CGIAR), the international research consortium of which CIMMYT is a part.

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2.GM CROPS STILL A CONCERN

February 6, 2003
The Leader-Post (Regina)

Russ Cullinane, a Canadian agricultural specialist working with farmers in Indonesia, was cited as saying that two major concerns about genetically modified crops persist, adding, "One is corporate control of agriculture, and two is whether sufficient environmental and human health research into these crops (is conducted) before they are approved."

And the concerns in Indonesia are similar to some of the concerns in Canada, he said.  Field trials of genetically modified (GM) cotton began in Indonesia in 2000, said Cullinane, who has worked in that country with the CUSO organization since 1998.  The corporate control issue stems from the concern that companies with an economic interest are "pushing their control in the developing world," he said.  Some fear crops are will be contaminated by GM cotton.  People worry that there could be problem with GM crops discovered down the road, he said.

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3.JUMPING GENES SEEN IN GM PLANT EXPERIMENT

February  6, 2003
The Australian

Genes in the chloroplast of a genetically-modified plant cell have been observed jumping into the cell's nucleus for the first time, Australian scientists have announced. But the researchers, from the University of Adelaide, said that their study of tobacco plants did not indicate genetically-modified (GM) crops are less safe. The work is described in today's issue of the journal Nature. Led by Associate Professor Jeremy Timmis, the group bred a marker gene into the plant's chloroplasts, semi-autonomous organelles inside each plant cell that are chiefly responsible for photosynthesis. They then looked for signs of the marker gene in 250,000 of the seeds the plant produced. In about one in every 16,000 seedlings, the marker gene had done the unexpected - it had moved into the nucleus of the cell, where DNA is stored and replication controlled. This means it not only migrated through the cytoplasm of the cell, but passed through the double membrane wall protecting the nucleus. Timmis downplayed the implications for GM plants, saying the marker gene used was specifically chosen for the purpose. And while movement of genes from chloroplast to nucleus does not occur naturally, there are many more processes before a complete and functional gene could make the migration. "We put a new gene in - but made it absolutely ready to be expressed in nucleus," he told ABC Science Online. "The gene was not expressed at all in the chloroplast, only if it ended up in the nucleus." It is possible to differentiate between the two regions as chloroplast genes are controlled in a completely different way, he said..

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4.JUMPING GENES LIVEN GM DEBATE

February  6, 2003
The Australian

Leigh Dayton
The debate on genetically modified crops is set to heat up, with Australian plant geneticists arguing that GM plants are not potential eco-vandals. In fact, the scientists -- from the University of Adelaide and CSIRO Plant Industry in Canberra -- report today in the journal Nature that genetically modified plants are "unlikely" to share modified genes with GM-free neighbours , as critics have warned. The researchers base their claim on a finding that genes jump around inside plant cells far more frequently than anyone expected. "There's an astoundingly high amount of jumping out of one compartment in the cell into another," said University of Adelaide associate professor Jeremy Timmis. Some may say that if genes jump around at such high rates that means the risk they will spread to nearby plants is equally high. Not so, says Professor Timmis, adding: "It's easy for the public to misinterpret such complex science. " Using funding from the Australian Research Council, Professor Timmis and his colleagues created two types of "marker" genes and inserted them into tobacco plant cells. They then looked for the markers in 250,000 of the plant's offspring.

One marker was designed to suit the nucleus where most of the plant's roughly 20,000 genes are found. The other was just right for the chloroplast, a separate "organelle" in the cell that converts sunlight into energy. In a quirk of nature, chloroplast genes are not transmitted by pollen, but by ovules contained in the female part of the plant. Professor Timmis's team found that in about one in 16,000 of the seedlings, a marker gene had jumped from the chloroplast into the nucleus and from there into a seedling. The catch is that only the nuclear markers were inherited as functional genes. Phil Davies, a plant geneticist with the South Australian Research and Development Institute in Adelaide, argues the work "rings a bell of caution" because the gene jumping rate was so high. "What worries me is that if they'd grown several million progeny (seedlings ), the chloroplast marker may have been seen as well," he said. But chief of CSIRO Plant Industry, Jim Peacock, who was not involved in the research, says Dr Davies is incorrect. "For instance, we've done hundreds of thousands of experiments with cotton and we've seen no evidence of gene transfer," he said.

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5.DIRECT MEASUREMENT OF THE TRANSFER RATE OF CHLOROPLAST DNA INTO THE NUCLEUS

February 5, 2003
Nature AOP, published online 5 February 2003
Chun Y. Huang*, Michael A. AyliffeÝ & Jeremy N. Timmis*
Department of Molecular Biosciences, The University of Adelaide, South Australia, 5005, Australia
Ý CSIRO Plant Industry, GPO Box 1600, Australian Capital Territory 2601, Australia

ABSTRACT:
Gene transfer from the chloroplast to the nucleus has occurred over evolutionary time1.  Functional gene establishment in the nucleus is rare, but DNA transfer without functionality is presumably more frequent. Here, we measured directly the transfer rate of chloroplast DNA (cpDNA) into the nucleus of tobacco plants (Nicotiana tabacum). To visualize this process, a nucleus-specific neomycin phosphotransferase gene (neoSTLS2) was integrated into the chloroplast genome, and the transfer of cpDNA to the nucleus was detected by screening for kanamycin-resistant seedlings in progeny. A screen for kanamycin-resistant seedlings was conducted with about 250,000 progeny produced by fertilization of wild-type females with pollen from plants containing cp-neoSTLS2. Sixteen plants of independent origin were identified and their progenies showed stable inheritance of neoSTLS2, characteristic of nuclear genes. Thus, we provide a quantitative estimate of one transposition event in about 16,000 pollen grains for the frequency of transfer of cpDNA to the nucleus. In addition to its evident role in organellar evolution, transposition of cpDNA to the nucleus in tobacco occurs at a rate that must have significant consequences for existing nuclear genes.