Elevated CO2 Improves the Physiology but Not the Final Yield in Spring Wheat Genotypes Subjected to Heat and Drought Stress During Anthesis

Abstract

Heat and drought events often occur concurrently as a consequence of climate change and have a severe impact on crop growth and yield. Besides, the accumulative increase in the atmospheric CO2 level is expected to be doubled by the end of this century. It is essential to understand the consequences of climate change combined with the CO2 levels on relevant crops such as wheat. This study evaluated the physiology and metabolite changes and grain yield in heat-sensitive (SF29) and heat-tolerant (LM20) wheat genotypes under individual heat stress or combined with drought applied during anthesis at ambient (aCO2) and elevated CO2 (eCO2) levels. Both genotypes enhanced similarly the WUE under combined stresses at eCO2. However, this increase was due to different stress responses, whereas eCO2 improved the tolerance in heat-sensitive SF29 by enhancing the gas exchange parameters, and the accumulation of compatible solutes included glucose, fructose, β-alanine, and GABA to keep water balance; the heat-tolerant LM20 improved the accumulation of phosphate and sulfate and reduced the lysine metabolism and other metabolites including N-acetylornithine. These changes did not help the plants to improve the final yield under combined stresses at eCO2. Under non-stress conditions, eCO2 improved the yield of both genotypes. However, the response differed among genotypes, most probably as a consequence of the eCO2-induced changes in glucose and fructose at anthesis. Whereas the less-productive genotype LM20 reduced the glucose and fructose and increased the grain dimension as the effect of the eCO2 application, the most productive genotype SF29 increased the two carbohydrate contents and ended with higher weight in the spikes. Altogether, these findings showed that the eCO2 improves the tolerance to combined heat and drought stress but not the yield in spring wheat under stress conditions through different mechanisms. However, under non-stress conditions, it could improve mainly the yield to the less-productive genotypes. Altogether, the results demonstrated that more studies focused on the combination of abiotic stress are needed to understand better the spring wheat responses that help the identification of genotypes more resilient and productive under these conditions for future climate conditions.

Priming with Small Molecule-Based Biostimulants to Improve Abiotic Stress Tolerance in Arabidopsis thaliana

“…Recently, it has also been related to the plant stress response. For example, [ 42 ] observed the AcOrn accumulation in a heat stress-tolerant and sensitive wheat lines under heat stress alone or combined with drought. It could be that plants accumulate AcOrn under stress as part of their plant defense, so it has been reported to promote the synthesis of methyl jasmonate in Arabidopsis [ 40 ].…”

“…The samples were lyophilized, and the obtained DW was used for the targeted metabolomic analysis. The analysis of the free amino acids and total and free polyamines was performed as described by [ 42 ]. Briefly, for the analysis of free amino acids, pulverized plant material (3–5 mg) was mixed with 1 mL of 50% EtOH and sonicated for 10 min (Bandelin, Germany).…”

Biochemical and structural basis of polyamine, lysine and ornithine acetylation catalyzed by spermine/spermidine N‐acetyl transferase in moss and maize

“…Polyamines and amino acids were quantified in accordance with previously described methods (Abdelhakim et al., 2022; Ćavar Zeljković et al., 2022). Briefly, pulverized sample material (3–5 mg) was mixed with 1 ml of 50% EtOH and sonicated for 10 min (https://bandelin.com/).…”

Plant nucleoside N‐ribohydrolases: riboside binding and role in nitrogen storage mobilization

“…The rosettes of Arabidopsis from the second phenotyping experiment were collected at the end of the experiment, and pooled together, ending with three to five independent pools (biological replicates). From each sample, various free polyamines were quantified after their benzoylation using UHPLC–MS/MS method performed on Shimadzu Nexera X2 UHPLC coupled with an MS‐8050 (https://www.shimadzu.com/) (Abdelhakim et al., 2022). Derivatized polyamines were analyzed on the Acquity UPLC BEH C18 column (https://www.waters.com/) in the mobile phase containing a mixture of 15 m m formic acid, pH 3.0, and methanol.…”

“…Quantification is based on the isotope dilution analysis method. For the quantification of free amino acids, a non‐derivatized approach based on HILIC chromatography was used (Abdelhakim et al., 2022). A total of 35 metabolites of free amino acids and polyamines were identified and quantified (Tables S6 and S7, Figures S3, S5, and S6).…”