Skip to Main Content
Thermotolerance and heat stress responses of Douglas-fir and ponderosa pine seedling populations from contrasting climatesAuthor(s): Danielle E. Marias; Frederick C. Meinzer; David R. Woodruff; Katherine A. McCulloh; David Tissue
Source: Tree Physiology. 37(3): 301-315.
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
View PDF (1005.0 KB)
DescriptionTemperature and the frequency and intensity of heat waves are predicted to increase throughout the 21st century. Germinant seedlings are expected to be particularly vulnerable to heat stress because they are in the boundary layer close to the soil surface where intense heating occurs in open habitats. We quantified leaf thermotolerance and whole-plant physiological responses to heat stress in first-year germinant seedlings in two populations each of Pinus ponderosa P. and C. Lawson (PIPO) and Pseudotsuga menziesii (Mirb.) Franco (PSME) from climates with contrasting precipitation and temperature regimes. Thermotolerance of detached needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. PSME was more heat tolerant than PIPO according to both independent assessments of thermotolerance. Following exposure of whole seedlings to a simulated heat wave at 45 °C for 1 h in a growth chamber, we monitored FV/FM, photosynthesis, stomatal conductance, non-structural carbohydrates (NSCs) and carbon isotope ratios (δ13C) for 14 days. Heat treatment induced significant reductions in FV/FM in both species and a transient reduction in photosynthetic gas exchange only in PIPO 1 day after treatment. Heat treatment induced an increase in glucose + fructose concurrent with a decrease in starch in both species, whereas total NSC and sucrose were not affected by heat treatment. The negative relationship between glucose + fructose and starch observed in treated plants may be due to the conversion of starch to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites displayed greater δ13C values than those from wetter sites, consistent with higher intrinsic water-use efficiency and drought resistance of populations from drier climates. Thermotolerance and heat stress responses appeared to be phenotypically plastic and representative of the environment in which plants were grown, whereas intrinsic water-use efficiency appeared to reflect ecotypic differentiation and the climate of origin.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMarias, Danielle E.; Meinzer, Frederick C.; Woodruff, David R.; McCulloh, Katherine A.; Tissue, David. 2016. Thermotolerance and heat stress responses of Douglas-fir and ponderosa pine seedling populations from contrasting climates. Tree Physiology. 37(3): 301-315. https://doi.org/10.1093/treephys/tpw117.
KeywordsCarbon isotope ratios, chlorophyll fluorescence, electrolyte leakage, heat stress, heat tolerance, non-structural carbohydrates, photosynthesis, stomatal conductance.
- Impacts of leaf age and heat stress duration on photosynthetic gas exchange and foliar nonstructural carbohydrates in Coffea arabica
- A stress wave based approach to NDE of logs for assessing potential veneer quality: Part I—small-diameter ponderosa pine.
- Two-dimensional heat flow analysis applied to heat sterilization of ponderosa pine and Douglas-fir square timbers
XML: View XML