iCal
Room:
Leipziger KUBUS I Hall 1AB (1 AB)
Topic:
1.2 Roots and carbon – from communication to carbon storage in soils
Form of presentation:
Lecture
Duration:
30 Minutes
02:00 pm
Root exudation in response to phosphorus limitation in upland rice
Dr. Christiana Staudinger | University of Natural Resources and Life Sciences (BOKU) Vienna | Austria
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Authors:
Dr. Christiana Staudinger | University of Natural Resources and Life Sciences (BOKU) Vienna | Austria
Eva Mundschenk
Vera Benyr
Maire Holz
Uxue Otxandorrena
Jun Wasaki
Matthias Wissuwa
Eva Oburger
Plants release root exudates into soil, which support rhizosphere microbiomes, contribute to the build-up of soil organic carbon and can chemically enhance the availability of nutrients in soils. Andosols are agriculturally important soils in Japan. They are characterised by high phosphate (P) adsorption capacities resulting in high fertilizer application rates. The mechanisms favoring the growth of efficient rice genotypes on acidic, highly P-fixing soils are still poorly understood and we hypothesised that rhizosphere processes might play a role in the mobilisation of P from the soil matrix. We analysed growth response, nutrient uptake and root exudation patterns of 11 rice genotypes grown on high P and low P Andosol. After 33 days, a 3-fold variation in P uptake under low P was observed among the genotypes tested. Root exudates were collected and relatively quantified using a metabolomic profiling approach (RP-LC-TOF) leading to the detection of several hundreds of features, of which subsets were enriched in the least P efficient genotypes. In addition, dissolved organic carbon, phenolic compound, total free amino acid and total sugar exudation rates were determined photometrically. Interestingly, dissolved organic carbon exudation rates and especially the exudation rates of phenolic compounds were highest in the least efficient genotypes. Our data suggest that enhanced soil exploration (maintained root growth together with low C exudation rates) is an important strategy of P efficient rice. Furthermore, enhanced C exudation and potential modification of the microbiome through exudation of phenolic compounds is a response of P inefficient genotypes grown on strongly P fixing Andosols.