NEWS FROM
PHYSIOLOGIA PLANTARUM
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Published monthly on behalf of SPPS by Wiley-Blackwell.
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Climate change causes greenhouse gas emission by plants
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Global warming seems to be self-sustaining by making plants emit the potent greenhouse gas, methane (CH4), while simultaneously reducing their assimilation of CO2. This conclusion was obtained by Mirwais M. Qaderi and David M. Reid from University of Calgary, Canada, who tested methane emission and several growth parameters from six crop species grown under various environmental conditions. An increase in temperature from 24/20 °C (day/night) to 30/26 °C led to a 15% increase in methane emission, while the effect of water stress, which will accompany global warming in many regions, increased emission of the greenhouse gas by 22%. The figures are average measurements from faba bean, sunflower, pea, canola, barley and wheat. Under ambient conditions the six crops emitted between 85 (barley) and 170 (pea) ng methane per g dry weight per hour. At the same time, the higher temperature caused CO2 assimilation to decrease 27%, while water stress reduced CO2 assimilation by 31%. The researchers will now investigate how elevated CO2 levels affect methane emission in order to get a better picture of how global warming can turn plants into greenhouse gas contributors.
Read full article free: Qaderi & Reid (October 2009) Physiologia Plantarum 137: 139-147
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NEWS IN BRIEF
FROM OTHER JOURNALS
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Amber Predates Conifers
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Source: Bray & Anderson (2 October 2009) Science 326: 132-134
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Shedding light on protein-protein interactions
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Source: Yazawa et al (4 October 2009) Nature Biotechnology doi:10.1038/nbt.1569
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Father of the Green Revolution has died
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Norman Borlaug realized that adequate food is only the first requisite for a decent and humane life. From raymondpronk.wordpress.com
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The American agronomist Norman Borlaug passed away on September 12, 95 years old. Borlaug was deemed the father of the Green Revolution that began in 1945 and transformed agriculture in many parts of the World. He was awarded the Nobel Peace Prize in 1970 for securing food supply in developing countries through his efforts to develop high yielding and robust crops. The Green Revolution led to substantial increases in food production - e.g. the wheat harvest tripled in developing countries from 1950 to 2000 - and is credited for saving millions of people from starvation.
The Green Revolution included a variety of technologies like breeding, pesticides, irrigation and fertilizers that roughly equally attributed to the increased and more stable yield. Norman Borlaug's initial work was carried out in Mexico, where he came in 1944 to head a newly established wheat research programme. His focus was on breeding for shorter cultivars that would not lodge (i.e. when tall, thin stalks bent over in wind or rain) and where photosynthates would be channelled to the grain instead of being invested in stalk production.
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Dwarf wheat with shorter stems played a significant role in the Green Revolution. From www.lsuagcenter.com
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To achieve this he used a Japanese semi-dwarf cultivar, Norin 10, which was later shown to have mutant copies of the Rht1 and Rht2 genes. These genes are involved in the signalling pathways of gibberellins, a group of plant hormones that regulate growth and developmental processes like e.g. stem elongation. The mutant genes causes insensitivity to gibberellins and leed to plants only about half or two third of the normal height. Another advantage of gibberellin insensitivity was that the new varieties did not respond to nitrogen fertilizers by unfavorable growth spurts but instead exhibited a more sustained growth response.
Another major focus of the enthusiastic breeder was to incorporate disease resistance into wheat. He achieved this by backcrossing multiple lines carrying different resistant genes with a single recurrent parental line, thereby creating several lines with similar traits but showing resistance to various pathogens. Farmers using this mixture of similar lines would consequently only loose a small part of their crop when a new pathogen emerged to their region and this would additionally halt the spread of the disease, thereby minimizing loss of the susceptible line as well.
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Borlaug's new wheat varieties caused a dramatic increase in world wide yield. From www.wikipedia.org
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Combining disease resistance and the semi dwarf phenotype created the two new varieties Pitic 62 and Penjamo 62, that dramatically increased yield. In 1963, the wheat harvest in Mexico was six times bigger than in 1944 when Borlaug started his breeding projects. At this time, Borlaug was heading the wheat programme at the newly established CIMMYT (International Maize and Wheat Improvement Center) in Mexico, and from here the new wheat varieties spread to the rest of the developing world, leading to similar increases in yield. Later in his life, Borlaug also contributed to develop higher yielding varieties of e.g. maize and barley and his principles were used to develop semi-dwarf and high-yield cultivars of indica and japonica rice.
Norman Borlaug was certainly not the single person responsible for the Green Revolution and in his 1970 Nobel Lecture he also stated, that one individual could not "symbolize the vital role of agriculture and food production in a world that is hungry, both for bread and for peace". He also acknowledged that though his work has been a change in the right direction, it did not transform the world into a Utopia. However, his humanistic ideas and enthusiastic work has certainly contributed to reduce famine and to increase food security for billions of poor people.
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