TR4‐triggered recruitment of suppressive rhizomicrobiome enhances Fusarium wilt resistance in banana

Abstract

Fusarium wilt of banana threatens banana production world‐wide. Although beneficial rhizomicrobiomes are linked to disease resistance, whether resistant cultivars systemically recruit disease‐suppressive rhizomicrobiomes after pathogen challenge remains unclear. Using a split‐root system combined with rhizomicrobiome transfer, we tested whether systemically recruited rhizomicrobiomes from different cultivars after pathogen challenge could alter disease development in a susceptible cultivar. Rhizosphere soil suspension from the pathogen‐challenged highly resistant cultivar GCTCV119 was the only donor treatment that significantly reduced the disease index in the susceptible recipient cultivar Guijiao No. 1. This effect was associated with pathogen‐induced enrichment of absolute bacterial abundance and absolute Bacillus abundance in the rhizosphere of GCTCV119, whereas such enrichment was not observed in the other donor cultivars. A syncom of seven Bacillus strains from the GCTCV119 rhizosphere most effectively reduced (by 90.20%) the disease index by the induction of plant resistance. Soil incubation showed that pathogen‐induced D‐sorbitol accumulation in GCTCV119 significantly increased total bacterial abundance and Bacillus abundance, and reduced the disease index. This study highlights pathogen‐triggered rhizomicrobiome reshaping, higher absolute bacterial abundance, and the suppressive role of Bacillus as key features linked to disease resistance in banana, providing insights into microbiome‐mediated disease suppression.