Big Biomass Boost for Drought-Prone Climates

Mike Mickelbart, an assistant professor of horticulture; Mike Hasegawa, a professor of horticulture; and Chal Yul Yoo, a horticulture graduate student, found that a genetic mutation in the research plant Arabidopsis thaliana reduces the number of stomata. But instead of limiting carbon dioxide intake, the gene creates a beneficial equilibrium.

"The plant can only fix so much carbon dioxide. The fewer stomata still allow for the same amount of carbon dioxide intake as a wild type while conserving water," said Mickelbart, whose results were published in the early online version of the journal The Plant Cell. "This shows there is potential to reduce transpiration without a yield penalty. _Cheminfo

Scientists at Purdue University have discovered a mutant plant gene -- GTL1 -- which shows the way for plants to produce significant biomass even in the face of drought conditions.

Mickelbart and Yoo used an infrared gas analyzer to determine the amount of carbon dioxide taken in and water lost in the Arabidopsis mutant.

Analysis showed that the plant, which has a mutant form of the gene GTL1, did not reduce carbon dioxide intake but did have a 20 percent reduction in transpiration. The plant had the same biomass as a wild type of Arabidopsis when its shoot dry weight was measured.

"The decrease in transpiration leads to increased drought tolerance in the mutant plants," Yoo said.

"They will hold more water in their leaves during drought stress."

The results have been published in the online version of the journal The Plant Cell. _NewKerala

Of the 20 genes known to control stomata, SDD1 was highly expressed in the mutant. SDD1 is a gene that is responsible for regulating the number of stomata on leaves. In the mutant, with GTL1 not functioning, SDD1 is highly expressed, which results in the development of fewer stomata.

Mickelbart said the finding is important because it opens the possibility that there is a natural way to improve crop drought tolerance without decreasing biomass or yield. He said the next step in the research is to determine the role of GTL1 in a crop plant.

The National Science Foundation and a Binational Agricultural Research and Development Award funded the research. _ScienceDaily

Change the genes, change the rules. Obviously such mutants occur spontaneously, in reaction to drought conditions. This places recent "research" claims by the high priesthood of global warming catastrophe in doubt. In fact, plants do have ways to amass greater CO2 in conditions of lowered water availability. The mechanism was provided by natural selection a long time ago.

In fact, most life forms on Earth evolved under conditions of far higher CO2 levels -- and highly variable climate conditions of cyclical drought, flood, heat, cold etc. It is time for computer modelers to stop trying to meddle in the global economy, to acquire a bit of much needed humility, and to stop stealing resources from society which would be more productively used in the private sector.