Aarhus University, Department of Food Science, Kirstinebjergvej 10, 5792, Aarslev, Denmark.
University of Copenhagen, Department of Plant and Environmental Sciences, Section for Crop Sciences, Højbakkegård Allé 30, 2630, Taastrup, Denmark.
Plant Physiol Biochem. 2018 Nov;132:213-221. doi: 10.1016/j.plaphy.2018.09.002. Epub 2018 Sep 5.
The incidence of heat episodes during the phase of reproductive development in crops is accountable for great yield losses worldwide. Plants subjected to stress events during vegetative stages (primed) are reported be more resistant to future stress exposure during the reproductive phases. We aimed to test if repeated early abiotic stresses could improve heat tolerance during anthesis in wheat cultivars. Two wheat cultivars (Triticum aestivum L.), 'Gladius' and 'Paragon', were subjected to a heat priming process consisting of two periods with heat at the developmental stages of three and five completely developed leaves, respectively. The primed and non-primed plants were later subjected to either a heat stress or non-heat stress (control) temperature for seven days during anthesis. Gas exchange and chlorophyll fluorescence were used to investigate the physiological performance of the plants. No difference in assimilation rate was observed between treatments for 'Gladius'. Measurements were not possible to obtain for heat stressed 'Paragon' plants due to premature senescence. We did not observe strong evidence to prove our hypothesis of early heat stress (priming) being accountable for improving heat tolerance. However, a significant difference between cultivars in response to heat stress was observed. The yield parameters of 'Gladius' primed plants did not differ from their respectively control treatment. A distinct result was observed for the heat sensitive cultivar 'Paragon', suggesting a cumulative deleterious effect caused by the repeated heat stress.
在作物生殖发育阶段，热事件的发生会导致全球范围内的巨大产量损失。有报道称，在营养生长阶段（预适应）经历胁迫事件的植物，在生殖阶段暴露于未来胁迫时更具抗性。我们旨在测试重复的早期非生物胁迫是否可以提高小麦品种在开花期的耐热性。我们对两个小麦品种（Triticum aestivum L.）“Gladius”和“Paragon”进行了热预适应处理，包括在三叶期和五叶期进行两次热处理。预适应和未预适应的植株随后在开花期经历七天的热胁迫或非热胁迫（对照）温度。我们使用气体交换和叶绿素荧光来研究植物的生理性能。对于“Gladius”，处理之间的同化率没有差异。由于过早衰老，无法对热胁迫的“Paragon”植株进行测量。我们没有观察到早期热胁迫（预适应）可提高耐热性的有力证据来支持我们的假设。然而，我们观察到了品种对热胁迫的响应存在显著差异。“Gladius”预适应植株的产量参数与其对照处理没有差异。对于热敏感品种“Paragon”，则观察到了明显不同的结果，这表明重复的热胁迫会导致累积的有害影响。
