Future CO₂, warming and water deficit impact white and red Tempranillo grapevine: Photosynthetic acclimation to elevated CO₂ and biomass allocation

Abstract

Due to the CO 2 greenhouse effect, elevated atmospheric concentration leads to higher temperatures, accompanied by episodes of less water availability in semiarid and arid areas or drought periods. Studies investigating these three factors (CO 2 , temperature and water availability) simultaneously in grapevine are scarce. The present work aims to analyze the combined effects of high CO 2 (700 ppm), high temperature (ambient +4 C) and drought on the photosynthetic activity, biomass allocation, leaf non-structural carbon composition, and carbon/nitrogen (C/N) ratio in grapevine. Two grapevine cultivars, red berry Tempranillo and white berry Tempranillo, were used, the latter being a natural, spontaneous mutant of the red cultivar. The experiment was performed on fruit-bearing cuttings during a 3-month period, from June (fruit set) to August (maturity). The plants were grown in research-oriented facilities, temperature-gradient greenhouses, where temperature, CO 2 , and water supply can be modified in a combined way.Drought had the strongest effect on biomass accumulation compared to the other environmental variables, and root biomass allocation was increased under water deficit. CO 2 and temperature effects were smaller and depended on cultivar, and on interactions with the other factors. Acclimation effects were observed on both cultivars as photosynthetic rates under high atmospheric CO 2 were reduced by long-term exposition to elevated CO 2 . Exposure to such high CO 2 resulted in increased starch concentration and reduced C/N ratio in leaves.A correlation between the intensity of the reduction in photosynthetic rates and the accumulation of starch in the leaves was found after prolonged exposure to elevated CO 2 . | INTRODUCTIONIn many agricultural areas, precipitation patterns are expected to change in the future, with more frequent drought events in semiarid and arid regions and others where precipitation will likely increase (IPCC, 2013). A Representative Concentration Pathway (RCP) is an atmospheric greenhouse gas concentration trajectory considered possible in the future by the Intergovernmental Panel on Climate Change (IPCC). With respect to CO 2 , the concentration may increase to somewhere between 670 and 936 ppm by the year 2100 (RCP 6.0 and RCP 8.5 respectively, depending on the volume of CO 2 emitted in the years to come) (Moss et al., 2008(Moss et al., , 2010. According to the concentration-driven Coupled Model Intercomparison Project 5 (CMIP5) model simulations, the CO 2 increases are expected to raise the global mean temperature by 2.2 ± 0.5 and 3.7 ± 0.7 C, respectively (IPCC, 2013;Taylor et al., 2012).

Assessment of Nutritional and Quality Properties of Leaves and Musts in Three Local Spanish Grapevine Varieties Undergoing Controlled Climate Change Scenarios

“…High temperature acting alone (ACET) did not affect the levels of soluble sugars (TSS) but did cause a marked decrease in the accumulation of starch in leaves of the three grapevine varieties (TV, AMB, and PAS). These results contrast with those obtained by Torres et al [23] and Kizildeniz et al [26] in cv. Red Tempranillo: the concentrations of TSS increased and those of starch did not change in the leaves when grown under warm temperatures.…”

“…In this period, leaves are an important source of carbohydrates for reserves restoration, developing vegetative organs, as well as for inflorescence and berry development [27], processes that may be hastened by warm temperatures, thus leading to a lower accumulation of starch in the leaves. In contrast, leaves in the studies of Torres et al [23] and Kizildeniz et al [26] were collected at fruit maturity when the amount of photosynthates destined to the bunch is becoming lower and the pool of starch reserves is already restored in the wood of most varieties [28]. In the present study, elevated CO 2 did not produce an accumulation of carbohydrates in leaves, which was associated with limitations in increasing C sink strength in plants developed under high air CO 2 [29,30].…”

“…Such different behavior may be explained by both the genetic back-ground of grapevine and the age of the leaves collected. Kizildeniz et al [26] observed differences between Red and White Tempranillo in the response of leaf TSS to elevated temperature. Also, in the present experiment, the leaves were harvested during the early reproductive stages.…”

Water Deficit Modulates the CO2 Fertilization Effect on Plant Gas Exchange and Leaf-Level Water Use Efficiency: A Meta-Analysis

“…Enclosed growing environments may be limited through the downregulation of photosynthesis ( Ainsworth and Long, 2005 ; Zhang et al, 2021 ). Under high light conditions, plants are generally better able to take advantage of increased [CO 2 ] due to altered N partitioning within the photosynthetic apparatus to favor light-harvesting complexes ( Yu et al, 2012 ; Kizildeniz et al, 2021 ). However, at low light levels, light-dependent reactions limit the rate of photosynthesis ( Assmann, 1999 ; Yu et al, 2012 ).…”

Assessing the growth dynamics of alfalfa varieties (Medicago sativa cv. Bilensoy 80 and Nimet) response to varied carbon dioxide (CO2) concentrations

“…Net photosynthesis and intercellular CO 2 concentration were assessed under atmospheric CO 2 conditions (approximately 400 ppm) and high CO 2 concentrations (600 ppm, 800 ppm and 1000 ppm) applied in each greenhouse, with a white LED light intensity of 1400 mol m 2 s −1 , and air cuvette temperatures ranging from 25 to 30 °C for both plants grown at ambient and enhanced CO 2 . Since stomatal conductance is utilized as a stress-related to water indicator [ 64 , 65 ], and it was not included as a treatment in this study, this parameter was not measured. Examinations of plants cultivated at current and increased CO 2 and assessed at the same CO 2 amount, either ambient or high, show photosynthetic acclimatization.…”