The effect of abrupt temperature increase on growth and phosphorus fractions of Pisum sativum
Pea plants were grown in controlled environments at 25/15 C day/night temperatures and transferred abruptly to each of three higher temperatures, 32/22, 35/25, and 38/28 C, to determine the effects on growth and development and on phosphorus fractions. Samples were taken for analysis on a logarithmic high-temperature exposure time scale. Rate of node formation increased sharply during the first 24 hours of exposure to the elevated temperatures and then declined to a rate which was somewhat greater than that of 25/15 C plants. Rate of internode elongation was initially stimulated and then slowed slightly during continued high temperature exposure. Inorganic phosphorus declined slightly within 10 minutes of temperature increase but increased to about three times the original level by 6 days. Organic, lipid, and nucleic acid and protein phosphorus were not appreciably affected by the temperature change.