A new outlook on sporadic flowering of bamboo.

Moso bamboo (Phyllostachys edulis) is a temperate grass species with a tree-like habitus and an unusual reproduction strategy. While flowering is irregular and infrequent, new clonal bamboo shoots are established from an underground rhizome network during the spring season. In our previous study, we performed transcriptome analyses using bamboo shoot buds to understand the initiation of bamboo stem elongation. Interestingly, the expression profile in the shoot apical meristem (SAM) region of young bamboo shoots is similar to that of other plants. Specifically, some of the genes that control the timing of flowering and floral development are active in the SAM region. This data raises the question of how bamboo shoots start to elongate, and why they do not proceed to a seasonal cycle of flowering. Our analyses of the activation of shoot buds and subsequent rapid stem elongation provide new hints to unravel the unpredictable flowering pattern of bamboo. In this short communication, we discuss how bamboo might coordinate and integrate the vegetative and reproductive phases in relation to shoot emergence and stem elongation.