Bertamini Massimo, Faralli Michele, Varotto Claudio, Grando Maria Stella, Cappellin Luca
Center Agriculture Food Environment (C3A), University of Trento, Via. E. Mach 1, 38010 San Michele all'Adige, Italy.
Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 San Michele all'Adige, Italy.
Plants (Basel). 2021 Jan 19;10(1):181. doi: 10.3390/plants10010181.
Rising temperature is among the most remarkably stressful phenomena induced by global climate changes with negative impacts on crop productivity and quality. It has been previously shown that volatiles belonging to the isoprenoid family can confer protection against abiotic stresses. In this work, two cv. 'Chardonnay' clones (SMA130 and INRA809) differing due to a mutation (S272P) of the DXS gene encoding for 1-deoxy-D-xylulose-5-phosphate (the first dedicated enzyme of the 2C-methyl-D-erythritol-4-phosphate (MEP) pathway) and involved in the regulation of isoprenoids biosynthesis were investigated in field trials and laboratory experiments. Leaf monoterpene emission, chlorophyll fluorescence and gas-exchange measurements were assessed over three seasons at different phenological stages and either carried out in in vivo or controlled conditions under contrasting temperatures. A significant ( < 0.001) increase in leaf monoterpene emission was observed in INRA809 when plants were experiencing high temperatures and over two experiments, while no differences were recorded for SMA130. Significant variation was observed for the rate of leaf CO assimilation under heat stress, with INRA809 maintaining higher photosynthetic rates and stomatal conductance values than SMA130 ( = 0.003) when leaf temperature increased above 30 °C. At the same time, the maximum photochemical quantum yield of PSII (F/F) was affected by heat stress in the non-emitting clone (SMA130), while the INRA809 showed a significant resilience of PSII under elevated temperature conditions. Consistent data were recorded between field seasons and temperature treatments in controlled environment conditions, suggesting a strong influence of monoterpene emission on heat tolerance under high temperatures. This work provides further insights on the photoprotective role of isoprenoids in heat-stressed , and additional studies should focus on unraveling the mechanisms underlying heat tolerance on the monoterpene-emitter grapevine clone.
气温上升是全球气候变化引发的最显著的胁迫现象之一，对作物的生产力和品质产生负面影响。此前已有研究表明，类异戊二烯家族的挥发性物质能够提供对非生物胁迫的保护。在本研究中，对两个霞多丽（‘Chardonnay’）品种克隆（SMA130和INRA809）进行了田间试验和实验室实验，这两个品种因编码1-脱氧-D-木酮糖-5-磷酸（2C-甲基-D-赤藓糖醇-4-磷酸（MEP）途径的首个专用酶）的DXS基因发生突变（S272P）而有所不同，该基因参与类异戊二烯生物合成的调控。在三个季节的不同物候阶段，对叶片单萜排放、叶绿素荧光和气体交换测量进行了评估，这些测量在体内或不同温度的对照条件下进行。在两个实验中，当植株处于高温时，INRA809的叶片单萜排放显著增加（<0.001），而SMA130未记录到差异。在热胁迫下，叶片CO同化速率存在显著差异，当叶片温度升高到30°C以上时，INRA809的光合速率和气孔导度值高于SMA130（=0.003）。同时，非排放型克隆（SMA130）的PSII最大光化学量子产率（F/F）受热胁迫影响，而INRA809在高温条件下PSII表现出显著的恢复能力。在田间季节和控制环境条件下的温度处理之间记录到了一致的数据，表明单萜排放在高温下对耐热性有强烈影响。这项工作为类异戊二烯在热胁迫下的光保护作用提供了进一步的见解，后续研究应专注于揭示单萜排放型葡萄品种耐热性的潜在机制。
