Symbiogenics may adapt rice plants to the impact of climate change

Rusty Rodriguez, a researcher at the United States Geological Survey (USGS) reports the development of  rice variety with increased tolerance to cold, salt and drought. Heat stress resistance has still to be added, because rice production is known to decreases by 10 percent for every temperature increase of 1-degree centigrade during the rice-growing season. [1]

The researchers at USGS colonized two commercial varieties of rice with the spores of fungi that exist naturally within native coastal dunegrass. Fungi which colonize the rice plants may confer stress tolerance to drought, salt and temperature, as well as increased seed yields and root systems in rice  These stressors are predicted to worsen due to climate change, and adapting rice plants to such changes is crucial because rice  provides nearly half the daily calories for the world’s population. These small fungi act as endophytes.

The term "endophytic" refers to a situation where one organism lives inside another. In this case, a fungus and grass form a relationship that is mutually beneficial and enhances the reproductive success of each. Another example of endophytic relationship is provided by researchers of the University of Rhode Island. They roprt that the fungal endophytes Acremonium coenophialum and A. lolii live within perennial ryegrass hosts. These endophytes are transferred from plant to plant via seed.  [2]

The USGS researchers named this emerging area of research "symbiogenics" for symbiosis-altered gene expression. The DNA of the rice plant itself is not changed. Removing the fungus from dunegrass, the plants are no longer salt tolerant,  indicating that no DNA change took place.

[1] Rusty Rodriguez, Catherine Puckett: Climate Adaptation of Rice Symbiogenics: a New Strategy for Reducing Climate Impacts on Plants. The United States Geological Survey (USGS). Released: 7/13/2011
http://www.usgs.gov/newsroom/article.asp?ID=2852&from=rss_home

[2] Endopyhte-Enhanced Grasses
http://www.uri.edu/ce/factsheets/sheets/endophyte.html