TY - JOUR

T1 - Root exposure to apple replant disease soil triggers local defense response and rhizoplane microbiome dysbiosis

AU - Balbín-Suárez, Alicia

AU - Jacquiod, Samuel

AU - Rohr, Annmarie Deetja

AU - Liu, Benye

AU - Flachowsky, Henryk

AU - Winkelmann, Traud

AU - Beerhues, Ludger

AU - Nesme, Joseph

AU - Sørensen, Søren J.

AU - Vetterlein, Doris

AU - Smalla, Kornelia

N1 - Publisher Copyright: © 2021 The Author(s). Published by Oxford University Press on behalf of FEMS.

PY - 2021

Y1 - 2021

N2 - A soil column split-root experiment was designed to investigate the ability of apple replant disease (ARD)-causing agents to spread in soil. 'M26' apple rootstocks grew into a top layer of Control soil, followed by a barrier-free split-soil layer (Control soil/ARD soil). We observed a severely reduced root growth, concomitant with enhanced gene expression of phytoalexin biosynthetic genes and phytoalexin content in roots from ARD soil, indicating a pronounced local plant defense response. Amplicon sequencing (bacteria, archaea, fungi) revealed local shifts in diversity and composition of microorganisms in the rhizoplane of roots from ARD soil. An enrichment of operational taxonomic units affiliated to potential ARD fungal pathogens (Ilyonectria and Nectria sp.) and bacteria frequently associated with ARD (Streptomyces, Variovorax) was noted. In conclusion, our integrated study supports the idea of ARD being local and not spreading into surrounding soil, as only the roots in ARD soil were affected in terms of growth, phytoalexin biosynthetic gene expression, phytoalexin production and altered microbiome structure. This study further reinforces the microbiological nature of ARD, being likely triggered by a disturbed soil microbiome enriched with low mobility of the ARD-causing agents that induce a strong plant defense and rhizoplane microbiome dysbiosis, concurring with root damage.

AB - A soil column split-root experiment was designed to investigate the ability of apple replant disease (ARD)-causing agents to spread in soil. 'M26' apple rootstocks grew into a top layer of Control soil, followed by a barrier-free split-soil layer (Control soil/ARD soil). We observed a severely reduced root growth, concomitant with enhanced gene expression of phytoalexin biosynthetic genes and phytoalexin content in roots from ARD soil, indicating a pronounced local plant defense response. Amplicon sequencing (bacteria, archaea, fungi) revealed local shifts in diversity and composition of microorganisms in the rhizoplane of roots from ARD soil. An enrichment of operational taxonomic units affiliated to potential ARD fungal pathogens (Ilyonectria and Nectria sp.) and bacteria frequently associated with ARD (Streptomyces, Variovorax) was noted. In conclusion, our integrated study supports the idea of ARD being local and not spreading into surrounding soil, as only the roots in ARD soil were affected in terms of growth, phytoalexin biosynthetic gene expression, phytoalexin production and altered microbiome structure. This study further reinforces the microbiological nature of ARD, being likely triggered by a disturbed soil microbiome enriched with low mobility of the ARD-causing agents that induce a strong plant defense and rhizoplane microbiome dysbiosis, concurring with root damage.

KW - phytoalexins

KW - root system architecture

KW - soil microbiome

KW - split-root experiment

KW - X-ray computed tomography

U2 - 10.1093/femsec/fiab031

DO - 10.1093/femsec/fiab031

M3 - Journal article

C2 - 33587112

AN - SCOPUS:85103683308

VL - 97

JO - F E M S Microbiology Ecology

JF - F E M S Microbiology Ecology

SN - 0168-6496

IS - 4

M1 - fiab031

ER -