Multigenerational Effects of Elevated CO2 and N Supply on Leaf Gas Exchange Traits in Wheat Plants

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The responses of leaf gas exchange of wheat (Triticum aestivum L.) to elevated atmospheric CO 2 concentration (e[CO 2]) were ofteninvestigated within a single generation, while the long-term acclimation of photosynthesis to growth in e[CO 2] over multiple gen-erations has not been systematically studied. Here, five wheat cultivars were grown under either ambient (a[CO 2], 400 ppm) orelevated (e[CO 2], 800 ppm) CO 2 concentration for three consecutive generations (G1 to G3) with two N-fertilisation levels (1N–1 gN pot−1 and 2N–2 g N pot−1) in climate-controlled greenhouses. Leaf gas exchange was determined in each generation of plantsunder different treatments. It was found that at both N levels, e[CO 2] stimulated photosynthetic rate while reducing stomatalconductance, transpiration rate and leaf N concentration, resulting in an enhanced water use efficiency and photosynthetic Nuse efficiency. The N level modulated the intergenerational responses of photosynthetic capacity to e[CO 2]; under low N supply,the maximum carboxylation rate (Vcmax), the maximum electron transport rate (Jmax) and the rate of triose phosphate utilisation(TPU) were significantly downregulated by e[CO 2] from the first to the second generation, but recovered in the third generation;whereas at high N levels, photosynthetic acclimation was diminished with the progress of generations, with Vcmax , Jmax andTPU increased under e[CO 2] in the third generation. These results suggest that intergenerational adaptation could alleviate thee[CO 2]-induced reduction of the photosynthetic capacity, but plants with different N status responded differently to adapt to thelong-term exposure to e[CO 2]. Among the five cultivars, 325Jimai showed a better photosynthetic performance under e[CO 2]over the three generations, while 02-1Shiluan appeared to be more inhibited by CO 2 elevation in the long term conditions. Thesefindings provide new insights for breeding strategies in the future CO 2 -enriched environments.
Original languageEnglish
Article numbere12722
JournalJournal of Agronomy and Crop Science
Volume210
Issue number4
Number of pages14
ISSN0931-2250
DOIs
Publication statusPublished - 2024

ID: 396402555