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Powdery mildew-resistant mutants
trends in plant science Headlines
Feeding the world in the 21st century The effects of the ‘Green Revolution’ cannot keep pace with today’s pace of population growth. A combination of problems has led to a decline in agricultural production and although in theory sufficient food is produced worldwide, the operation of market economies means that the equal distribution of food is not a reality. The prognosis is not good with .800 million people living a life of permanent or intermittent hunger. The application of advances in plant breeding, particularly tissue culture and genetic engineering, will be essential if the yields of farmers and yield ceilings are to be increased. The use of excessive quantities of pesticide needs to be reduced and the nutrient value of basic foods increased. Farmers on less-favored lands need plant varieties that are better able to tolerate drought, salinity and lack of soil nutrients. The required input traits of plants are: resistance to parasites in various crops; delayed senescence, dwarfing, reduced shade avoidance and early flowering in rice; tolerance to aluminum, chilling and freezing in cereals; new plant types for weed control and for increased yield potential in rice. The required output traits of plants are: increased b-carotene in rice and oilseed rape; increased bioavailable iron in maize and rice; modified starch in rice, potato and maize; modified fatty-acid content in oilseed rape; increased bioavailable protein, essential amino acids, seed weight and sugar content in maize; lowered inert cellulose (lignin) content in forage crops. Nature (2000), 402 (Suppl.), C55–C58.
Hard time for EU plant biotechnology Plant biotechnology research faces more hurdles within the current EC Framework than in previous programs. Because multinational corporations always have the option to move their research efforts to other parts of the world, European plant science could lose out in the long run. Science (2000) 287, 790–791. 190
May 2000, Vol. 5, No. 5
Soybean diesel additive
Weed-killing Fusarium protein
Galen Suppes and Joseph Heppert (University of Kansas, USA) have developed and evaluated formulas for soybean oil-based cetane improvers with good results. Fuel additives improve lubricity and the performance of diesel fuel, and particularly diesel fuel containing ethanol. When the additive is used in combination with 10% ethanol in diesel, significant reductions in emissions can be achieved: only 500 ppm are needed to have full effect. Ethanol fuel is manufactured from corn and grain sorghum, and ethanol production is the third largest user of corn in the USA, behind feed and export uses.
Bryan Bailey and co-workers (Agricultural Research Service, Beltsville, MD, USA) are spraying weeds with a natural protein derived from the soil fungus Fusarium oxysporum. Upon entering the stomata, the fungus’ protein causes the initiation of a massive hypersensitive response, leading to mass cellular suicide. In tests with dandelions (Taraxacum officinale), the weed’s affected leaves are killed three to 24 hours later. Bailey’s team originally studied a fungus protein called Nep1, which now appears only to affect broadleaf dicot weeds with cell receptors that can detect the protein. http://www.ars.usda.gov/is/AR/archive/feb00/ weeds0200.htm
Isoflavone biosynthesis The natural roles of isoflavones are in plant defense and root nodulation, but they would also be beneficial to human health. The gene encoding isoflavone synthase has been reported in a range of leguminous species as well as in sugarbeet, and can be expressed in Arabidopsis. Nat. Biotechnol. (2000) 18, 208–212.
Powdery mildewresistant mutants Four loci involved in powdery mildew resistance have been identified among 20 recessive Arabidopsis mutants. Resistance is not simply the result of constitutive activation of the salicylic acid- or ethylene- and jasmonic aciddependent defense pathways. Results suggest that one mutation is of a specific resistance mechanism. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 1897–1902.
Multiple resistant potato Breeding for resistance to late blight in potatoes is difficult, but Robert Plaisted and collegues (Cornell University, USA) have developed a new potato ‘New York 121’ with resistance to late blight as well as to golden nematodes, scab and potato virus Y (PVY). Typically it takes 14 years to bring a newly tested and developed potato to the market place, but New York 121 took less than a decade. There are yield tradeoffs in exchange for disease resistance – the potato is good for boiling, but not for making French fries or chips (crisps).
Public relations effort A new initiative, CropGen, comprises a panel of scientists and specialists on agriculture, plant science, microbiology, ecology and consumer affairs to provide information for the public, interest groups and the media. The panel will be able to give a perspective on key issues in the GM crop debate, such as human health, environmental impact and the benefits versus the risks. CropGen will be funded initially by a consortium of biotechnology companies but the panel will be independent. The sponsors include Aventis Crop Science, Dow AgroSciences, Monsanto and Novartis Seeds, but the companies have signed an undertaking that they cannot veto any of the scientific positions taken by the panel.
Epidermal cells effected by fiddlehead Epidermal cells remain relatively inert, but during reproductive development and fertilization the epidermis is developmentally more labile and participates in two types of contactmediated cell interactions: organ fusion and pollen hydration. The fiddlehead gene encodes a protein that is probably involved in the synthesis of long-chain lipids that are thought to localize extracellularly and probably modify the properties of the cuticle. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 1311–1316. Internet news media, edited by Gert E. de Vries.
Feeding the world in the 21st century The effects of the ‘Green Revolution’ cannot keep pace with today’s pace of population growth. A combination of problems has led to a decline in agricultural production and although in theory sufficient food is produced worldwide, the operation of market economies means that the equal distribution of food is not a reality. The prognosis is not good with .800 million people living a life of permanent or intermittent hunger. The application of advances in plant breeding, particularly tissue culture and genetic engineering, will be essential if the yields of farmers and yield ceilings are to be increased. The use of excessive quantities of pesticide needs to be reduced and the nutrient value of basic foods increased. Farmers on less-favored lands need plant varieties that are better able to tolerate drought, salinity and lack of soil nutrients. The required input traits of plants are: resistance to parasites in various crops; delayed senescence, dwarfing, reduced shade avoidance and early flowering in rice; tolerance to aluminum, chilling and freezing in cereals; new plant types for weed control and for increased yield potential in rice. The required output traits of plants are: increased b-carotene in rice and oilseed rape; increased bioavailable iron in maize and rice; modified starch in rice, potato and maize; modified fatty-acid content in oilseed rape; increased bioavailable protein, essential amino acids, seed weight and sugar content in maize; lowered inert cellulose (lignin) content in forage crops. Nature (2000), 402 (Suppl.), C55–C58.
Hard time for EU plant biotechnology Plant biotechnology research faces more hurdles within the current EC Framework than in previous programs. Because multinational corporations always have the option to move their research efforts to other parts of the world, European plant science could lose out in the long run. Science (2000) 287, 790–791. 190
May 2000, Vol. 5, No. 5
Soybean diesel additive
Weed-killing Fusarium protein
Galen Suppes and Joseph Heppert (University of Kansas, USA) have developed and evaluated formulas for soybean oil-based cetane improvers with good results. Fuel additives improve lubricity and the performance of diesel fuel, and particularly diesel fuel containing ethanol. When the additive is used in combination with 10% ethanol in diesel, significant reductions in emissions can be achieved: only 500 ppm are needed to have full effect. Ethanol fuel is manufactured from corn and grain sorghum, and ethanol production is the third largest user of corn in the USA, behind feed and export uses.
Bryan Bailey and co-workers (Agricultural Research Service, Beltsville, MD, USA) are spraying weeds with a natural protein derived from the soil fungus Fusarium oxysporum. Upon entering the stomata, the fungus’ protein causes the initiation of a massive hypersensitive response, leading to mass cellular suicide. In tests with dandelions (Taraxacum officinale), the weed’s affected leaves are killed three to 24 hours later. Bailey’s team originally studied a fungus protein called Nep1, which now appears only to affect broadleaf dicot weeds with cell receptors that can detect the protein. http://www.ars.usda.gov/is/AR/archive/feb00/ weeds0200.htm
Isoflavone biosynthesis The natural roles of isoflavones are in plant defense and root nodulation, but they would also be beneficial to human health. The gene encoding isoflavone synthase has been reported in a range of leguminous species as well as in sugarbeet, and can be expressed in Arabidopsis. Nat. Biotechnol. (2000) 18, 208–212.
Powdery mildewresistant mutants Four loci involved in powdery mildew resistance have been identified among 20 recessive Arabidopsis mutants. Resistance is not simply the result of constitutive activation of the salicylic acid- or ethylene- and jasmonic aciddependent defense pathways. Results suggest that one mutation is of a specific resistance mechanism. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 1897–1902.
Multiple resistant potato Breeding for resistance to late blight in potatoes is difficult, but Robert Plaisted and collegues (Cornell University, USA) have developed a new potato ‘New York 121’ with resistance to late blight as well as to golden nematodes, scab and potato virus Y (PVY). Typically it takes 14 years to bring a newly tested and developed potato to the market place, but New York 121 took less than a decade. There are yield tradeoffs in exchange for disease resistance – the potato is good for boiling, but not for making French fries or chips (crisps).
Public relations effort A new initiative, CropGen, comprises a panel of scientists and specialists on agriculture, plant science, microbiology, ecology and consumer affairs to provide information for the public, interest groups and the media. The panel will be able to give a perspective on key issues in the GM crop debate, such as human health, environmental impact and the benefits versus the risks. CropGen will be funded initially by a consortium of biotechnology companies but the panel will be independent. The sponsors include Aventis Crop Science, Dow AgroSciences, Monsanto and Novartis Seeds, but the companies have signed an undertaking that they cannot veto any of the scientific positions taken by the panel.
Epidermal cells effected by fiddlehead Epidermal cells remain relatively inert, but during reproductive development and fertilization the epidermis is developmentally more labile and participates in two types of contactmediated cell interactions: organ fusion and pollen hydration. The fiddlehead gene encodes a protein that is probably involved in the synthesis of long-chain lipids that are thought to localize extracellularly and probably modify the properties of the cuticle. Proc. Natl. Acad. Sci. U. S. A. (2000) 97, 1311–1316. Internet news media, edited by Gert E. de Vries.