Stress in native grasses under ecologically relevant heat waves

Future increases in the intensity of heat waves (high heat and low water availability) are predicted to be one of the most significant impacts on organisms. Using six native grasses from Eastern Australia, we assessed their capacity to tolerate heat waves with low water availability. We were interested in understanding differential response between native grasses of differing photosynthetic pathways in terms of physiological and some molecular parameters to ecologically relevant summer heat waves that are associated with low rainfall. We used a simulation heatwave event in controlled temperature cabinets and investigated effects of the different treatments on four stress indicators: leaf senescence, leaf water content, photosynthetic efficiency and the relative expression of two heat shock proteins, Hsp70 and smHsp17.6. Leaf senescence was significantly greater under the combined stress treatment, while declines in leaf water content and photosynthetic efficiency were much larger for C3...

未来热浪（高温与低水分可利用性）强度的增加预计将成为对生物最显著的影响之一。我们以澳大利亚东部的六种本土草本植物为研究对象，评估了它们在低水分条件下耐受热浪的能力。我们旨在探究具有不同光合途径（photosynthetic pathways）的本土草本植物，在与低降雨量相关的、生态相关性夏季热浪中，其生理及部分分子参数的差异响应。我们在可控温培养箱中模拟热浪事件，并研究了不同处理对四项胁迫指标的影响：叶片衰老、叶片含水量、光合效率，以及两种热休克蛋白（heat shock proteins）——Hsp70和smHsp17.6的相对表达量。在复合胁迫处理下，叶片衰老显著加剧；而对于C3植物，其叶片含水量及光合效率的下降幅度更大……