Controlled Environment Studies on the Temperature Responses of Leaf Extension in Species ofPoawith Diverse Altitudinal Ranges

Publisher Website
Google Scholar
Abstract
Woodward, F. I. and Friend, A. D. 1988. Controlled environment studies on the temperature responses of leaf extension in species of Poa with diverse altitudinal ranges.—J. exp. Bot. 39:411–420. Measurements of leaf extension were made on Poa pratensis L. (lowland origin), P. alpina L. (from mid-altitudes) and P. alpina ssp. vivipara Arcangeli (from high altitudes) at temperatures between 0.5 °C and 26°C. Both the rate of leaf extension above 15°C and the low temperature threshold of extension were inversely correlated with the altitude from which the species originated. In all species both the solute potential in the region of cell enlargement and the leaf extension rate decreased as the growth temperature was reduced from 18°C to 5°C. Pressure potential was not significantly affected in P. pratensis but increased in the other two species. In P. pratensis and P. alpina in vitro measurements of leaf plasticity (an estimate of the plastic extensibility of expanding cell walls) also decreased between 18°C and 5°C, suggesting that low cell wall extensibility, rather than leaf turgor, limits leaf extension at low temperatures. In vivo measurements of plastic extensibility confirmed the conclusion that low extensibility is likely to be the major limit to extension close to the low temperature threshold, in P. pratensis and P. alpina. In all three species leaf turgor becomes more important in the control of extension rate as temperature increases. At 5°C and 18°C the pressure potential of all three species was positively correlated with leaf elasticity, suggesting an additional temperature sensitive component in the control of leaf extension.

This publication has 0 references indexed in Scilit: