Plants can't escape from stressful environments, but they can be surprisingly flexible when subjected to extreme temperatures and shifting rainfall patternsboth likely to become more common under current climate-change scenarios.
Researchers from nine countries will discuss one system that plants use to cope with stress at the 2010 International CAM Workshop, hosted by the Smithsonian Tropical Research Institute at the Earl S. Tupper Research and Conference Center in Panama City, Panama from March 22-24, 2010. They will present new information about sources of biofuels, plants' abilities to adapt to extreme temperatures and drought, and models of flexible plant gene expression in response to environmental change.
Some of the most conspicuous tropical plants, the orchids and bromeliads, grow high on exposed tree branches where water is scarce even during the rainy season. In Panama, there are more than 1,150 orchid species and 180 species of bromeliads. The most extreme epiphytesplants that grow on other plantsinclude the nearly rootless air plant Tillandsia usneoides, Spanish moss.
A key innovation that makes it possible for these plants to occupy such stressful environments is their water-conserving form of photosynthesis. By taking in atmospheric carbon dioxide at night when it's cool outside--plants that have CAM, for Crassulacean Acid Metabolism, lose less water in carbohydrate production than do plants that take up carbon dioxide during the day and use the more standard C3 photosynthesis.
The astonishing diversity of CAM species including pineapple, aloe, cacti and Clusia trees native to Panama, makes them a major focus of the tropical plant physiology program at the Smithsonian. All trees are not alike in terms of water use. For example, because of its water-conserving CAM pathway Clusia rosea, called Cop in Spanish, needs 80% less water for biomass production than teak, a C3 plant.
|Contact: Beth King|
Smithsonian Tropical Research Institute