TY - JOUR

T1 - Role of root hair elongation in rhizosheath aggregation and in the carbon flow into the soil

AU - Teixeira, Pedro Paulo C.

AU - Trautmann, Svenja

AU - Buegger, Franz

AU - Felde, Vincent J.M.N.L.

AU - Pausch, Johanna

AU - Müller, Carsten W.

AU - Kögel-Knabner, Ingrid

N1 - Funding Information: This project was carried out in the framework of the priority program 2089 “Rhizosphere spatiotemporal organisation—a key to rhizosphere functions” funded by DFG, German Research Foundation (project number 403633986). We acknowledge Caroline Marcon and Frank Hochholdinger (University of Bonn) for providing maize seeds used in this experiment. We acknowledge Louis Rees and Diana Fernanda Butron Ballesteros for performing the aggregate fractionation procedure and processing the samples for analysis.

PY - 2023/4

Y1 - 2023/4

N2 - One of the most prominent changes in the rhizospheric soil structure is associated with the formation of a strongly bound soil layer in the surroundings of the root, which is named rhizosheath. In this study, we investigated how root hair elongation, a ubiquitous root morphological trait, affect the stability of rhizosheath aggregates. Using 13CO2 pulse labeling, we tracked the fate of root-derived 13C inputted into the rhizosheath of two Zea mays L. genotypes with contrasting root hair elongation: a mutant with root hair defective elongation (rth3) and a corresponding wild type (WT). In addition, we also investigated the differences between two 13CO2 labeling approaches (single vs. multiple pulse labeling) in the distribution of 13C in the rhizosheath aggregates. We were able to demonstrate that the rhizosheath aggregate stability and the resulting aggregate size distribution follows the same mechanisms irrespective of the root hair elongation. This result reinforces the assumption that other soil properties are more decisive for the soil structure formation in the rhizosheath in comparison to root hair elongation. The majority of recently deposited root-derived C (57%) was found in the macroaggregates. Increasing the number of pulses (multiple pulse labeling approach) resulted in a higher 13C enrichment of the rhizosheath aggregates fractions in comparison to the application of a single pulse. While both labeling approaches resulted in a similar distribution of 13C in the rhizosheath aggregates, the higher enrichment given by multiple pulse labeling allowed the separation of significant differences between the genotypes in plant C allocation in the rhizosheath.

AB - One of the most prominent changes in the rhizospheric soil structure is associated with the formation of a strongly bound soil layer in the surroundings of the root, which is named rhizosheath. In this study, we investigated how root hair elongation, a ubiquitous root morphological trait, affect the stability of rhizosheath aggregates. Using 13CO2 pulse labeling, we tracked the fate of root-derived 13C inputted into the rhizosheath of two Zea mays L. genotypes with contrasting root hair elongation: a mutant with root hair defective elongation (rth3) and a corresponding wild type (WT). In addition, we also investigated the differences between two 13CO2 labeling approaches (single vs. multiple pulse labeling) in the distribution of 13C in the rhizosheath aggregates. We were able to demonstrate that the rhizosheath aggregate stability and the resulting aggregate size distribution follows the same mechanisms irrespective of the root hair elongation. This result reinforces the assumption that other soil properties are more decisive for the soil structure formation in the rhizosheath in comparison to root hair elongation. The majority of recently deposited root-derived C (57%) was found in the macroaggregates. Increasing the number of pulses (multiple pulse labeling approach) resulted in a higher 13C enrichment of the rhizosheath aggregates fractions in comparison to the application of a single pulse. While both labeling approaches resulted in a similar distribution of 13C in the rhizosheath aggregates, the higher enrichment given by multiple pulse labeling allowed the separation of significant differences between the genotypes in plant C allocation in the rhizosheath.

KW - C pulse labeling

KW - Dry-crushing

KW - Isotopes

KW - Maize (Zea mays L.)

KW - Rhizosheath

KW - Rhizosphere soil aggregates

UR - http://www.scopus.com/inward/record.url?scp=85149051656&partnerID=8YFLogxK

U2 - 10.1007/s00374-023-01708-6

DO - 10.1007/s00374-023-01708-6

M3 - Article

AN - SCOPUS:85149051656

VL - 59

SP - 351

EP - 361

JO - Biology and fertility of soils

JF - Biology and fertility of soils

SN - 0178-2762

IS - 3

ER -