Julius Kühn Institute (JKI) - Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11-12, 38104 Braunschweig, Germany.
Copenhagen University, Department of Biology, Section of Microbiology, Universitetsparken 15, 2100 Copenhagen, Denmark.
FEMS Microbiol Ecol. 2021 Mar 8;97(3). doi: 10.1093/femsec/fiab018.
Long-term agricultural practices are assumed to shape the rhizosphere microbiome of crops with implications for plant health. In a long-term field experiment, we investigated the effect of different tillage and fertilization practices on soil and barley rhizosphere microbial communities by means of amplicon sequencing of 16S rRNA gene fragments from total community DNA. Differences in the microbial community composition depending on the tillage practice, but not the fertilization intensity were revealed. To examine whether these soil and rhizosphere microbiome differences influence the plant defense response, barley (cultivar Golden Promise) was grown in field or standard potting soil under greenhouse conditions and challenged with Blumeria graminis f. sp. hordei (Bgh). Amplicon sequence analysis showed that preceding tillage practice, but also aboveground Bgh challenge significantly influenced the microbial community composition. Expression of plant defense-related genes PR1b and PR17b was higher in challenged compared to unchallenged plants. The Bgh infection rates were strikingly lower for barley grown in field soil compared to potting soil. Although previous agricultural management shaped the rhizosphere microbiome, no differences in plant health were observed. We propose therefore that the management-independent higher microbial diversity of field soils compared to potting soils contributed to the low infection rates of barley.
长期的农业实践被认为会影响作物根际微生物群落，从而影响植物健康。在一项长期田间试验中，我们通过对土壤和大麦根际微生物群落的总群落 DNA 进行 16S rRNA 基因片段的扩增子测序，研究了不同耕作和施肥措施对土壤和大麦根际微生物群落的影响。结果表明，微生物群落组成的差异取决于耕作方式，而不是施肥强度。为了研究这些土壤和根际微生物群落差异是否会影响植物防御反应，我们在温室条件下，将大麦（品种 Golden Promise）种植在田间或标准盆栽土壤中，并受到禾谷布氏白粉菌（Bgh）的挑战。扩增子序列分析表明，先前的耕作方式，以及地上 Bgh 挑战，显著影响了微生物群落组成。与未受挑战的植物相比，受挑战的植物中与植物防御相关的基因 PR1b 和 PR17b 的表达更高。与盆栽土壤相比，在田间土壤中生长的大麦的 Bgh 感染率明显较低。尽管先前的农业管理塑造了根际微生物群落，但在植物健康方面没有观察到差异。因此，我们提出，与盆栽土壤相比，田间土壤中独立于管理的更高微生物多样性有助于降低大麦的感染率。
