Abstract：
Heat-priming improves plants\' tolerance to a recurring heat stress event. The underlying molecular mechanisms of heat-priming are largely unknown in seagrasses. Here, ad hoc mesocosm experiments were conducted with two Mediterranean seagrass species, Posidonia oceanica and Cymodocea nodosa. Plants were first exposed to heat-priming, followed by a heat-triggering event. A comprehensive assessment of plant stress response across different levels of biological organization was performed at the end of the triggering event. Morphological and physiological results showed an improved response of heat-primed P. oceanica plants while in C. nodosa both heat- and non-primed plants enhanced their growth rates at the end of the triggering event. As resulting from whole transcriptome sequencing, molecular functions related to several cellular compartments and processes were involved in the response to warming of non-primed plants, while the response of heat-primed plants involved a limited group of processes. Our results suggest that seagrasses acquire a primed state during the priming event, that eventually gives plants the ability to induce a more energy-effective response when the thermal stress event recurs. Different species may differ in their ability to perform an improved heat stress response after priming. This study provides pioneer molecular insights into the emerging topic of seagrass stress priming and may benefit future studies in the field.
摘要：
热引发可提高植物对反复发生的热应激事件的耐受性。在海草中，热引发的潜在分子机制在很大程度上是未知的。这里,对两种地中海海草物种进行了临时中观实验，大洋波西多氏菌和结球藻。植物首先暴露于热引发中，接着是一个热触发事件。在触发事件结束时，对不同生物组织水平的植物胁迫响应进行了全面评估。形态和生理结果表明，热引发的大洋假发植物的反应得到了改善，而在结节性念珠菌中，热引发的和非引发的植物在触发事件结束时都提高了其生长速率。作为全转录组测序的结果，与几个细胞区室和过程相关的分子功能参与了对非引发植物变暖的反应，而热引发植物的反应涉及有限的一组过程。我们的结果表明，海草在启动事件期间获得了启动状态，这最终使植物能够在热应激事件复发时诱导更能量有效的反应。不同的物种在引发后执行改善的热应激反应的能力可能不同。这项研究为海草胁迫引发这一新兴主题提供了先驱分子见解，并可能有益于该领域的未来研究。
