Variation of ¹³C and ¹⁵N enrichments in different plant components of labeled winter wheat (Triticum aestivum L.)

Abstract

Information on the homogeneity and distribution of 13carbon (13C) and nitrogen (15N) labeling in winter wheat (Triticum aestivum L.) is limited. We conducted a dual labeling experiment to evaluate the variability of 13C and 15N enrichment in aboveground parts of labeled winter wheat plants. Labeling with 13C and 15N was performed on non-nitrogen fertilized (−N) and nitrogen fertilized (+N, 250 kg N ha−1) plants at the elongation and grain filling stages. Aboveground parts of wheat were destructively sampled at 28 days after labeling. As winter wheat growth progressed, δ13C values of wheat ears increased significantly, whereas those of leaves and stems decreased significantly. At the elongation stage, N addition tended to reduce the aboveground δ13C values through dilution of C uptake. At the two stages, upper (newly developed) leaves were more highly enriched with 13C compared with that of lower (aged) leaves. Variability between individual wheat plants and among pots at the grain filling stage was smaller than that at the elongation stage, especially for the −N treatment. Compared with those of 13C labeling, differences in 15N excess between aboveground components (leaves and stems) under 15N labeling conditions were much smaller. We conclude that non-N fertilization and labeling at the grain filling stage may produce more uniformly 13C-labeled wheat materials, whereas the materials were more highly 13C-enriched at the elongation stage, although the δ13C values were more variable. The 15N-enriched straw tissues via urea fertilization were more uniformly labeled at the grain filling stage compared with that at the elongation stage.

Post-anthesis Relationships Between Nitrogen Isotope Discrimination and Yield of Spring Wheat Under Different Nitrogen Levels

“…Studies have shown that there is a possible interaction between grain isotope discrimination in the aboveground dry matter and grain yield; yet studies on this interaction are few, especially during the crop's main growth stages (Liang et al, 2013;Chen et al, 2016;Sun et al, 2019). As a result, further information about N isotope discrimination during N uptake and absorption is needed to effectively track the remobilization of N that had been accumulated during the early crop growth stages and the post-anthesis phase under field conditions.…”

Long‐term fertilization and plastic film mulching modify temporal incorporation of 13C/15N‐labelled particulate organic matter

“…Finally, pulse‐labelled plant materials ( 13 C 15 N‐labelled stalk) were used in this experiment, in which δ 13 C maize stalk is approximately 8% higher than that of the whole maize plant and δ 15 N maize stalk is approximately 5% lower than that of the whole maize plant (Wang, Xu, Pei, et al, 2020; Zheng et al, 2018). Its heterogeneity would cause subtle differences in each treatment throughout the whole cultivation period (Sun et al, 2019). This measured difference between whole maize and stalk δ 13 C and δ 15 N values would amount to a potential overestimate (or underestimate) of <10% for maize stalk incorporation and fate dynamics, as based here on the whole maize 13 C and 15 N values.…”

Reduced belowground allocation of freshly assimilated C contributes to negative plant-soil feedback in successive winter wheat rotations

“…In WW, higher exudation for increased nutrient uptake is observed from early growth until owering with a decreasing trend thereafter until full maturity (Sun et al, 2018). At this late developmental stage, C is transported to the head during starch synthesis of the grains (Sun et al, 2019) In light of no Ggt-resistant WW cultivars (Palma-Guerrero et al, 2021), the projected adverse climatic conditions for WW both at European and global scale (Senapati et al, 2021;Zhu et al, 2022) and the premature status of the Ggt-speci c biocontrol research (Osborne et al, 2018;Zhao et al, 2023), there is an urgent need to decipher the mechanisms by which the rotational positions of WW in uences its productivity. Here, we investigated how different rotational positions of WW in uence the allocation of freshly assimilated C in above-and belowground plant parts and its subsequent translocation to the rhizosphere of WW.…”