Autor:innen:
Nicolas Tyborski | University of Bayreuth | Germany
Benedikt Bartel | University of Bayreuth | Germany
Andreas J. Wild | University of Bayreuth | Germany
Tina Koehler | ETH (Zurich) | Switzerland
Franziska Steiner | Technical University of Munich | Germany
Shu-Yin Tung | Bavarian State Research Center for Agriculture (LfL) | Germany
Andrea Carminati | ETH (Zurich) | Switzerland
Carsten W. Mueller | University of Copenhagen | Denmark
Alix Vidal | Wageningen University & Research | Netherlands
Sebastian Wolfrum | Bavarian State Research Center for Agriculture (LfL) | Germany
Barbara Eder | Bavarian State Research Center for Agriculture (LfL) | Germany
Jennifer Groth | Bavarian State Research Center for Agriculture (LfL) | Germany
Wouter Vahl | Bavarian State Research Center for Agriculture (LfL) | Germany
Johanna Pausch | University of Bayreuth | Germany
Tillmann Lueders | University of Bayreuth | Germany
Drought tolerance has become a key property of crop plants under ongoing anthropogenic climate change. Many plants form a mutualistic relationship with arbuscular mycorrhizal fungi (AMF), which improve the access of their host to nutrients and water. Understanding and fostering the interaction between crops and AMF seems of promise to improve crop performance under drought. Here, we aim to reveal distinctions between varieties of Zea mays L. in their overall mycorrhization and mycorrhizal responsiveness to drought. We hypothesize that mycorrhizal plasticity differs between landraces and modern breeds of maize.
For a general (non-species specific) assessment of AMF abundance, we have adapted a novel method based on quantitative PCR (qPCR) for use with Z. mays. In brief, the method measures the amount of AMF DNA relative to the amount of plant DNA present in a sample. Using samples from greenhouse and field trials, we compared AMF abundances for a range of twelve Z. mays varieties, grown under well-watered and water reduced conditions.
Mycorrhization rates differed between maize varieties. Hybrid breeds showed higher overall mycorrhization compared to other varieties. The response to drought contrasted between greenhouse and field conditions. While we observed increased mycorrhization under water-reduced conditions in the field trial, the opposite pattern occurred under the conditions of the greenhouse experiment.
We show that the qPCR approach offers a viable alternative to conventional microscopy-based methods for AMF quantification, with better reproducibility, avoidance of observer bias and higher throughput. The response of AMF to drought seems complex. While the increase in abundance under field conditions might be an adaptation which improves water availability to the plant, under certain conditions, other factors than drought seem to have a stronger influence on AMF abundance. Since AMF also have a key role in phosphorus provision, differences in plant demand for phosphorus between treatments might explain some of the patterns observed here.