The Role of Ethylene in Plant Growth and Development

Assessing local adaptation vs. plasticity under different resource conditions in seedlings of a dominant boreal tree species

“…Experiments with similar CO 2 treatments to our study found that black spruce responded to the elevated CO 2 conditions through increases in height growth, shoot mass and non-structural carbohydrates as well as decreases in stomatal conductance, leaf nitrogen content and SLA ( Tjoelker et al 1998 ; Bigras and Bertrand 2006 ). However, it should be noted that these experiments did not indicate that the CO 2 used to elevate the experimental CO 2 conditions had been scrubbed of ethylene—a plant growth hormone that can result in effects such as increased shoot elongation and diameter ( Abeles 1971 ), and it is a known contaminant in CO 2 cylinders ( Morison and Gifford 1984 ). There is also evidence to support no effect of CO 2 on physiological and morphological traits in previous studies ( Johnsen and Seiler 1996 ).…”