Leaf Monoterpene Emission Limits Photosynthetic Downregulation under Heat Stress in Field-Grown Grapevine

Abstract

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 Vitis vinifera 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 (p < 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 CO2 assimilation under heat stress, with INRA809 maintaining higher photosynthetic rates and stomatal conductance values than SMA130 (p = 0.003) when leaf temperature increased above 30 °C. At the same time, the maximum photochemical quantum yield of PSII (Fv/Fm) 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 Vitis vinifera, and additional studies should focus on unraveling the mechanisms underlying heat tolerance on the monoterpene-emitter grapevine clone.

Does co-inoculation of mycorrhiza and Piriformospora indica fungi enhance the efficiency of chlorophyll fluorescence and essential oil composition in peppermint under irrigation with saline water from the Caspian Sea?

“…In the present experiment, a correlation observed between the ETR and some essential oil ( Fig 14 ) confirms the fact that monoterpene emissions maintain PSII stability in stressed plants by partitioning excess electrons into other sinks of the terpenoid biosynthetic pathway [ 57 ]. A similar relationship between monoterpene emission, increasing Fv/Fm ratio, and ETR was reported in many other plants under different kinds of stress [ 57 , 58 ]. Besides, high ETR values observed in mycorrhizal plants can be attributed to a better physiological status, changes in the pattern of carbon partitioning, and accumulation and biosynthesis of terpenes.…”

“…by partitioning excess electrons into other sinks of the terpenoid biosynthetic pathway [57]. A similar relationship between monoterpene emission, increasing Fv/Fm ratio, and ETR was reported in many other plants under different kinds of stress [57,58].…”

Stress-Induced Volatile Emissions and Signalling in Inter-Plant Communication

“…Abiotic factors such as high light intensity [ 200 ], nutrient availability [ 201 ], salinity [ 11 ], temperature [ 29 , 72 , 73 , 104 , 202 ], wind and UV radiation [ 203 , 204 ], ozone exposure [ 205 ], and mechanical damage [ 5 ] have also been shown to induce VOC emissions in plants. In response to abiotic stress, VOCs offer protection against high-temperature exposure in addition to improving the thermo-tolerance of photosynthetic tissues [ 22 , 206 , 207 , 208 , 209 , 210 ]. To alleviate the negative effects of oxidative stress induced in response to environmental stressors, plant VOCs can stabilise and protect cellular membranes by quenching ROS species or by altering ROS signalling [ 211 , 212 ].…”

Effects of Elevated Atmospheric Carbon Dioxide on the Vineyard System of Vitis vinifera: A Review

“…The earliest agriculture was cultivated between 23,000 and 12,000 years ago (Weiss et al 2004), with the earliest grape domestication estimated between 6,000 and 9,000 years ago (Terral et al 2009). Grapevine has historically been sensitive to changes in climate, including the "Little Ice Age" in Europe (Mariani et al 2018) and the more recent heat waves of the 21 st century (Galat Giorgi et al 2019, Venios et al 2020, Bertamini et al 2021.…”

“…Mean climate projections underestimate the impact of climate change on grapevine, in particular the impact of extreme temperature spikes/drops in areas growing premier winegrapes, currently characterized by few days with extreme heat or cold (White et al 2006. While vines in Mediterranean areas will have to adapt to a more variable climate, elevated CO2 will compound the effects of heat and drought stress at a global scale, impacting the quality and quantity of grapevine yield (Jones et al 2005, Schultz 2010, Mosedale et al 2016, Van Leeuwen and Darriet 2016, Bertamini et al 2021. Carbon dioxide levels present a relatively novel challenge as they have been increasing at an unprecedented rate since the start of the Industrial Revolution (IPCC 2014).…”