Maize (Zea mays L.) root exudation profiles change in quality and quantity during plant development – A field study

Santangeli, Michael; Steininger-Mairinger, Teresa; Vetterlein, Doris; Hann, Stephan; Oburger, Eva

doi:10.1016/j.plantsci.2023.111896

Cited by 20 publications

(9 citation statements)

References 97 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: Discussionsupporting

confidence: 91%

“…The C-thresholds for late season exudates were not different from those for sugars, amino acids, and organic acids. This corresponds to the findings of Santangeli et al (2024) reporting that late-season exudates consist to over 50% of soluble carbohydrates. On the other hand, the C-thresholds for microbial growth in response to early season exudates and mucilage were an order of magnitude higher, at 2.53 and 6.33 µg C µg Cmic-C -1 respectively, indicating that these rhizodeposits were less supportive for microbial growth.…”

Section: Discussionsupporting

confidence: 91%

“…In addition, soluble exudates are released behind the root tip into the soil matrix, where mucilage has already induced the growth of a significant proportion of the microbial biomass. The majority of maize exudates is composed of sugars (Santangeli et al (2024), and therefore one would intuitively expect their rapid microbial metabolisation, and a replacement of K-strategists by r-strategists with faster turnover rates. Interestingly, after the typical initial up-regulation of microbial metabolism in response to root exudates, the expected exponential microbial growth was not realised.…”

Section: Discussionmentioning

confidence: 99%

“…Exudates and mucilage of maize ( Zea mays B73 wild type) were collected in the same field experiment as described above (Vetterlein et al, 2021). Exudates were collected in the early vegetation period during leaf development (BBCH 14), and in the late vegetation period at the first ripening stage (BBCH 83) (Lancashire et al, 1991) by a soil hydroponic-hybrid approach as described in Santangeli et al (2024). Briefly, soil-grown plants were grown in perforated soil columns in the field which allowed excavation of the entire intact maize plants.…”

Section: Methodsmentioning

confidence: 99%

“…The microbial activity decreases strongly with distance from the root surface (Vetterlein et al, 2020). The spatial expansion of the rhizosphere is influenced by the amount and composition of rhizodeposits, their diffusion and sorption in soils, which is a function of plant age, photosynthetic activity, root morphology and soil texture, but also depends on their degradation by microbial activity (Hertenberger et al, 2002; Ma et al, 2018; Molina et al, 2001; Santangeli et al, 2024).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Microbial utilisation of maize rhizodeposits applied to an agricultural soil at a range of concentrations

Niedeggen,

Rüger,

Oburger

et al. 2024

Preprint

Self Cite

View full text Add to dashboard Cite

Rhizodeposition fuels carbon (C) and nutrient cycling in soil. However, the dynamics of microbial growth on rhizodeposits in relation to the distance from the root have not been well studied. This study investigates microbial growth on individual organic components of rhizodeposits and on maize root-derived exudates and mucilage from an agricultural soil. By creating a gradient of substrate concentrations, we simulated reduced microbial access to rhizosphere C with increasing distance to the root surface. We identified distinct C-thresholds for the activation of microbial growth, and these were significantly higher for rhizodeposits compared to singular, simple sugars. In addition, testing for stoichiometric constraints of microbial growth by supplementing N and P showed accelerated and increased microbial growth by activating a larger proportion of the microbial biomass. Early and late season exudates triggered significantly different microbial growth responses. The mineralisation of early season exudates was induced at a high C-threshold, whereas the mineralisation of late season exudates showed 'sugar-like' properties, with a low C-threshold, high substrate affinity, and a reduced maximum respiration rate. Mucilage exhibited the highest C-threshold for the activation of microbial growth, although with a short lag-period and with an efficient mucilage degradation comparable to that of sugars. By determining kinetic parameters and turnover times for different root-derived substrates, our data enable the upscaling of micro-scale processes to the whole root system, allowing more precise predictions of how rhizodeposits drive microbial C and nutrient dynamics in soil.

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Microbial utilisation of maize rhizodeposits applied to an agricultural soil at a range of concentrations

Niedeggen,

Rüger,

Oburger

et al. 2024

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

Rhizosphere bacteriome assemblage following initial fluctuations is delayed with nitrogen additions in tomato seedlings

Dixon,

Rohrbaugh,

Manter

et al. 2024

Biol Fertil Soils

View full text Add to dashboard Cite

Root exudation patterns of contrasting rice (Oryza sativa L.) lines in response to P limitation

Schwalm,

Staudinger,

Hajirezaei

et al. 2024

Planta

View full text Add to dashboard Cite

Main conclusion Rice exudation patterns changed in response to P deficiency. Higher exudation rates were associated with lower biomass production. Total carboxylate exudation rates mostly decreased under P-limiting conditions. Abstract Within the rhizosphere, root exudates are believed to play an important role in plant phosphorus (P) acquisition. This could be particularly beneficial in upland rice production where P is often limited. However, knowledge gaps remain on how P deficiency shapes quality and quantity of root exudation in upland rice genotypes. We therefore investigated growth, plant P uptake, and root exudation patterns of two rice genotypes differing in P efficiency in semi-hydroponics at two P levels (low P = 1 µM, adequate P = 100 µM). Root exudates were collected hydroponically 28 and 40 days after germination to analyze total carbon (C), carbohydrates, amino acids, phenolic compounds spectrophotometrically and carboxylates using a targeted LC–MS approach. Despite their reported role in P solubilization, we observed that carboxylate exudation rates per unit root surface area were not increased under P deficiency. In contrast, exudation rates of total C, carbohydrates, amino acids and phenolics were mostly enhanced in response to low P supply. Overall, higher exudation rates were associated with lower biomass production in the P-inefficient genotype Nerica4, whereas the larger root system with lower C investment (per unit root surface area) in root exudates of the P-efficient DJ123 allowed for better plant growth under P deficiency. Our results reveal new insights into genotype-specific resource allocation in rice under P-limiting conditions that warrant follow-up research including more genotypes.

show abstract

Maize (Zea mays L.) root exudation profiles change in quality and quantity during plant development – A field study

Cited by 20 publications

References 97 publications

Microbial utilisation of maize rhizodeposits applied to an agricultural soil at a range of concentrations

Microbial utilisation of maize rhizodeposits applied to an agricultural soil at a range of concentrations

Rhizosphere bacteriome assemblage following initial fluctuations is delayed with nitrogen additions in tomato seedlings

Root exudation patterns of contrasting rice (Oryza sativa L.) lines in response to P limitation

Contact Info

Product

Resources

About