Targeted Manipulation of Vertically Transmitted Endophytes to Confer Beneficial Traits in Grapevines

Abstract

Vertically transmitted endophytes (VTEs) with multi-host-supporting functions are considered plant-acquired heritable traits, which can be manipulated to develop plants with the stable inheritance of these VTEs, defined here as ‘plant endophytic modification (PEM)’. To translate this hypothetical strategy into agricultural and horticultural practice, a PEM was carried out by introducing an anti-fungal pathogenic bacterium, Bacillus cereus (strain ID: ZX-2), into grapevine cuttings and growing the cuttings into vine plants. Bacterial strain XZ-2 is highly efficient in infecting grapevine cuttings and colonizing the interior of the infected cuttings, various parts of the subsequently established vine plants, and next year’s emerging vine shoots and leaves. Profiling the endophytic microbiota by high-throughput sequencing to the grapevines revealed that the colonization with exogenous ZX-2 slightly affected endophytic diversity, while significantly altering the composition and the predicted phenotypes of endophytic microbiota in ZX-2-modified grapevines (ZX-2mg). Most importantly, leaves (from both first- and second-year grapevines) of ZX-2mg conferred significantly higher (p p B. cereus (ZX-2) isolation rates was observed. In addition, ZX-2mg showed some growth promotion and a delay (15–20 days) in leaf abscission. The work established an alternative strategy to create plant lines with functions of specific VTEs via PEM, confirming the practical value of PEM in future organic farming systems.

Keywords

• vertically transmitted endophytes (VTEs)
• cutting treatment
• plant endophytic modification (PEM)
• acquired heritable trait
• disease resistance
• organic farming