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Ozone complicates crop yield projection
trends in plant science Headlines
GM artichokes used for fuel The cardoon artichoke (Cynara cardunculus) grows to a height of 3 m with 7-m-long roots. Jesus Fernandez (School of Engineer Agronomists of Madrid, Spain) has developed a variety of genetically modified artichokes that will be grown to fuel two power plants, each consuming 105 000 tons of artichokes a year, producing 91.2 GW of electricity per year. Farmers will receive European subsidies of £100 per ha (£40 per acre) to grow the artichokes.
Site-directed mutagenesis A system has been developed for site-directed mutagenesis in plants. It has been dubbed the pinpoint technique because it takes advantage of the plant’s DNA repair system and makes use of specifically designed hairpin-shaped molecules of DNA and RNA. Herbicideresistant plants have been successfully generated by inducing a single nucleotide change. Nat. Biotechnol. (2000) 18, 555–558.
GM mycorrhiza Ectomycorrhizal fungi provide a major network in the soil for making nutrients available to tree-root systems by breaking down minerals locked up by acidic soils. During reforestation young trees can be attacked by less friendly fungi. Researchers at the Michigan Institute of Technology are transferring fungicidal proteins that are toxic to other fungi. Although biodegradable and completely harmless to humans, these fungicidal proteins would protect tree roots from drought and attack by various microbial pathogens. The system, when fully developed, also has the potential to be adapted to handle a variety of other problems associated with plant health.
Seed plant phylogeny The phylogenetic relationships among the five groups of existing seed plants have been studied by generating a new molecular data set of mitochondrial small subunit rRNA sequences, and analyzing these data together with comparable data sets for the nuclear small subunit rRNA gene and the chloroplast rbcL gene. Combined analyses of all three genes strongly support monophyly of extant gymnosperms 276
July 2000, Vol. 5, No. 7
and the placement of Gnetales (although extremely divergent) within conifers as the sister group to the Pinaceae. Many morphological similarities between angiosperms and Gnetales (e.g. double fertilization and flowerlike reproductive structures) arose independently. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 4086–4091.
SAR turned to good use EDEN Bioscience (www.edenbio.com) have developed Messenger® – a product for disease management, plant growth enhancement and insect, mite and nematode suppression activities. The US Environmental Protection Agency approved registration of the rapidly degradable biochemical pesticide in April (www.epa. gov/pesticides). The active ingredient in Messenger® is a protein known as harpin from the bacterium Erwinia. It binds to plant receptors and activates natural defense and growth systems. Once activated, a plant is better able to naturally protect itself against a broad spectrum of bacteria, viruses and fungi, as well as repel, suppress or tolerate certain insects, mites and nematodes. In addition, these plant pathways enhance plant vigor and stress tolerance, and increase nutrient uptake and photosynthesis.
Bt corn healthier Patrick F. Dowd (Agricultural Research Service entomologist, Peoria, IL, USA) has found that levels of the mycotoxin fumonisin are 30- to 40-fold lower in Bt corn (corn that expresses Bacillus thuringiensis toxins) than in non-Bt varieties in Illinois cornfields. Corn varieties that expressed the Bt protein throughout the plant rather than in specific areas were the least likely to have significant fumonisin levels. Mycotoxins are potential cancer-causing agents, often found at elevated levels in insectdamaged produce (http://www.ars. usda.gov/ is/pr/2000/000426.htm).
Arabidopsis thermotolerance mutants Four separate mutants, hot1–4, that are unable to acquire thermotolerance to high-temperature stress have been described in Arabidopsis. One mutant, hot1, was found to be in the heat shock protein 101 and more specifically in its ATPase activity. Hsp101 is also required for thermotolerance in bacteria and yeast. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 4392–4397.
First wine from new Australian grape variety One of four grape varieties, Tyrian, especially designed for Australian conditions by CSIRO Plant Industry has produced the first wine. Cabernet Sauvignon was crossed with a Spanish grape, Sumoll, to produce highquality red-wine grapes suitable for Australia, with higher juice titratable acidity, slightly larger berries and larger bunches, high total ionized anthocyanins and phenolics with a bright hue. Commercial quantities of the varieties will be available within the next five years.
Ozone complicates crop yield projection By 2050, the amount of CO2 in the atmosphere is expected to be twice preindustrial levels. Agricultural Research Service scientists lead by Joseph E. Miller (Raleigh, NC, USA) have found that if plants are under ozone or water stress, CO2 enrichment stimulates growth and increases yield to a greater extent because of reduced ozone damage. When plants were grown in an atmosphere with low levels of ozone, increasing CO2 concentration did not always stimulate growth appreciably. This suggests that crop yields in environments that have high levels of CO2 might not be as high as models have suggested (http://www.ars.usda.gov/is/AR/ archive/apr00/ozone0400.htm).
1360 - 1385/00/$ – see front matter © 2000 Elsevier Science Ltd. All rights reserved.
GM artichokes used for fuel The cardoon artichoke (Cynara cardunculus) grows to a height of 3 m with 7-m-long roots. Jesus Fernandez (School of Engineer Agronomists of Madrid, Spain) has developed a variety of genetically modified artichokes that will be grown to fuel two power plants, each consuming 105 000 tons of artichokes a year, producing 91.2 GW of electricity per year. Farmers will receive European subsidies of £100 per ha (£40 per acre) to grow the artichokes.
Site-directed mutagenesis A system has been developed for site-directed mutagenesis in plants. It has been dubbed the pinpoint technique because it takes advantage of the plant’s DNA repair system and makes use of specifically designed hairpin-shaped molecules of DNA and RNA. Herbicideresistant plants have been successfully generated by inducing a single nucleotide change. Nat. Biotechnol. (2000) 18, 555–558.
GM mycorrhiza Ectomycorrhizal fungi provide a major network in the soil for making nutrients available to tree-root systems by breaking down minerals locked up by acidic soils. During reforestation young trees can be attacked by less friendly fungi. Researchers at the Michigan Institute of Technology are transferring fungicidal proteins that are toxic to other fungi. Although biodegradable and completely harmless to humans, these fungicidal proteins would protect tree roots from drought and attack by various microbial pathogens. The system, when fully developed, also has the potential to be adapted to handle a variety of other problems associated with plant health.
Seed plant phylogeny The phylogenetic relationships among the five groups of existing seed plants have been studied by generating a new molecular data set of mitochondrial small subunit rRNA sequences, and analyzing these data together with comparable data sets for the nuclear small subunit rRNA gene and the chloroplast rbcL gene. Combined analyses of all three genes strongly support monophyly of extant gymnosperms 276
July 2000, Vol. 5, No. 7
and the placement of Gnetales (although extremely divergent) within conifers as the sister group to the Pinaceae. Many morphological similarities between angiosperms and Gnetales (e.g. double fertilization and flowerlike reproductive structures) arose independently. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 4086–4091.
SAR turned to good use EDEN Bioscience (www.edenbio.com) have developed Messenger® – a product for disease management, plant growth enhancement and insect, mite and nematode suppression activities. The US Environmental Protection Agency approved registration of the rapidly degradable biochemical pesticide in April (www.epa. gov/pesticides). The active ingredient in Messenger® is a protein known as harpin from the bacterium Erwinia. It binds to plant receptors and activates natural defense and growth systems. Once activated, a plant is better able to naturally protect itself against a broad spectrum of bacteria, viruses and fungi, as well as repel, suppress or tolerate certain insects, mites and nematodes. In addition, these plant pathways enhance plant vigor and stress tolerance, and increase nutrient uptake and photosynthesis.
Bt corn healthier Patrick F. Dowd (Agricultural Research Service entomologist, Peoria, IL, USA) has found that levels of the mycotoxin fumonisin are 30- to 40-fold lower in Bt corn (corn that expresses Bacillus thuringiensis toxins) than in non-Bt varieties in Illinois cornfields. Corn varieties that expressed the Bt protein throughout the plant rather than in specific areas were the least likely to have significant fumonisin levels. Mycotoxins are potential cancer-causing agents, often found at elevated levels in insectdamaged produce (http://www.ars. usda.gov/ is/pr/2000/000426.htm).
Arabidopsis thermotolerance mutants Four separate mutants, hot1–4, that are unable to acquire thermotolerance to high-temperature stress have been described in Arabidopsis. One mutant, hot1, was found to be in the heat shock protein 101 and more specifically in its ATPase activity. Hsp101 is also required for thermotolerance in bacteria and yeast. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 4392–4397.
First wine from new Australian grape variety One of four grape varieties, Tyrian, especially designed for Australian conditions by CSIRO Plant Industry has produced the first wine. Cabernet Sauvignon was crossed with a Spanish grape, Sumoll, to produce highquality red-wine grapes suitable for Australia, with higher juice titratable acidity, slightly larger berries and larger bunches, high total ionized anthocyanins and phenolics with a bright hue. Commercial quantities of the varieties will be available within the next five years.
Ozone complicates crop yield projection By 2050, the amount of CO2 in the atmosphere is expected to be twice preindustrial levels. Agricultural Research Service scientists lead by Joseph E. Miller (Raleigh, NC, USA) have found that if plants are under ozone or water stress, CO2 enrichment stimulates growth and increases yield to a greater extent because of reduced ozone damage. When plants were grown in an atmosphere with low levels of ozone, increasing CO2 concentration did not always stimulate growth appreciably. This suggests that crop yields in environments that have high levels of CO2 might not be as high as models have suggested (http://www.ars.usda.gov/is/AR/ archive/apr00/ozone0400.htm).
1360 - 1385/00/$ – see front matter © 2000 Elsevier Science Ltd. All rights reserved.