Culturomics of the plant prokaryotic microbiome and the dawn of plant-based culture media – A review

•The plant microbiome culturomics is substantially lagging behind the human microbiome.•Conventional chemically-synthetic culture media recover < 10% of plant-associated microbiota.•Plant-based culture media (PCM) are introduced as a novel tool for plant microbiome culturomics.•PCM extended the microbiota culturability to recover unculturable bacterial taxa.•Streamlined- and large-genomes conspicuously contribute to the dilemma of unculturability.