Moler Ehren Reid Von, Kolb Thomas, Brady Anne, Palmiero Briana Nicole, Wallace Taylor Robert, Waring Kristen Marie, Whipple Amy Vaughn
Department of Biological Sciences Northern Arizona University Flagstaff AZ USA.
School of Forestry Northern Arizona University Flagstaff AZ USA.
Plant Environ Interact. 2021 Jun 20;2(3):148-164. doi: 10.1002/pei3.10055. eCollection 2021 Jun.
Seedling emergence, survival, morphological and physiological traits, and oxidative stress resistance of southwestern white pine ( Engelm.) were studied in response to warming treatments applied during embryogenesis, germination, and early seedling growth. Daytime air temperature surrounding cones in tree canopies was warmed by +2.1°C during embryo development. Resulting seeds and seedlings were assigned to three thermal regimes in growth chambers, with each regime separated by 4°C to encompass the wide range of temperatures observed over space and time across the species' range, plus the effect of heat waves coupled with a high carbon emissions scenario of climate warming. The embryo warming treatment reduced percent seedling emergence in all germination and growth environments and reduced mortality of seedlings grown in the warmest environment. Warm thermal regimes during early seedling growth increased subsequent seedling resistance to oxidative stress and transpirational water use. Experimental warming during seed development, germination, and seedling growth affected seedling emergence and survival. Oxidative stress resistance, morphology, and water relations were affected only by warming imposed during germination and seedling growth. This work explores potential outcomes of climate warming on multiple dimensions of seedling performance and uniquely illustrates that plant responses to heat vary with plant developmental stage in addition to the magnitude of temperature change.
研究了西南白松（Engelm.）在胚胎发育、萌发和幼苗早期生长过程中接受升温处理后的出苗、存活、形态和生理特征以及抗氧化胁迫能力。在胚胎发育期间，树冠中球果周围的日间气温升高了2.1°C。将得到的种子和幼苗分配到生长室中的三种热环境中，每种热环境相差4°C，以涵盖该物种在空间和时间上观察到的广泛温度范围，以及热浪的影响和高碳排放情景下的气候变暖效应。胚胎升温处理降低了所有萌发和生长环境中的幼苗出苗率，并降低了在最温暖环境中生长的幼苗的死亡率。幼苗早期生长期间的温暖热环境增加了后续幼苗对氧化胁迫和蒸腾水分利用的抗性。种子发育、萌发和幼苗生长期间的实验性升温影响了幼苗的出苗和存活。抗氧化胁迫能力、形态和水分关系仅受萌发和幼苗生长期间施加的升温影响。这项工作探讨了气候变暖对幼苗性能多个维度的潜在影响，并独特地表明，除了温度变化的幅度外，植物对热量的反应还随植物发育阶段而变化。
