Case study of a rhizosphere microbiome assay on a bamboo rhizome with excessive shoots.

Young moso bamboo shoots are a popular seasonal food and an important source of income for farmers, with value for cultivation estimated at $30,000 per hectare. Bamboo also has great environmental importance and its unique physiology is of scientific interest. A rare and valuable phenomenon has recently appeared where a large number of adjacent buds within a single moso bamboo rhizome have grown into shoots. Although of practical importance for the production of edible shoots, such occurrences have not been scientifically studied, due to their rarity. Analysis of collected reports from enhanced shoot production events in China showed no evidence that enhanced shoot development was heritable. We report the analysis of the rhizosphere microbiome from a rhizome with 18 shoots, compared to rhizomes having one or no shoots as controls. The community of prokaryotes, but not fungi, correlated with the shoot number. Burkholderia was the most abundant genus, which was negatively correlated with rhizome shoot number, while Clostridia and Ktedonobacteria were positively correlated. Two Burkholderia strains were isolated and their plant-growth promoting activity was tested. The isolated Burkholderia strains attenuated the growth of bamboo seedlings. These data provide the first study on excessive shoot development in bamboo, which will facilitate hypothesis building for future studies.