Genome-wide analysis and transcriptomic profiling of the auxin biosynthesis, transport and signaling family genes in moso bamboo (Phyllostachys heterocycla)

Background: Auxin is essential for plant growth and development. Although substantial progress has been made in understanding auxin pathways in model plants such as Arabidopsis and rice, little is known in moso bamboo which is famous for its fast growth resulting from the rapid cell elongation and division. Results: Here we showed that exogenous auxin has strong effects on crown and primary roots. Genes involved in auxin action, including 13 YUCCA (YUC) genes involved in auxin synthesis, 14 PIN-FORMED/PIN-like (PIN/PILS) and 7 AUXIN1/LIKE-AUX1 (AUX1/LAX) members involved in auxin transport, 10 auxin receptors (AFB) involved in auxin perception, 43 auxin/indole-3-aceticacid (AUX/IAA) genes, and 41 auxin response factors (ARF) involved in auxin signaling were identified through genome-wide analysis. Phylogenetic analysis of these genes from Arabidopsis, Oryza sativa and bamboo revealed that auxin biosynthesis, transport, and signaling pathways are conserved in these species. A comprehensive study of auxin-responsive genes using RNA sequencing technology was performed, and the results also supported that moso bamboo shared a conserved regulatory mechanism for the expression of auxin pathway genes; meanwhile it harbors its own specific properties. Conclusions: In summary, we generated an overview of the auxin pathway in bamboo, which provides information for uncovering the precise roles of auxin pathway in this important species in the future.