The role of metabolic pathways regulated by the microRNA156 in bud outgrowth

Abstract

Shoot architecture is an important factor that determines crop yield. It plays a significant role in resource acquisition and utilization and environmental adaptation. Shoot architecture is also an important factor impacting plant biomass production. The formation of axillary meristems and lateral buds and their subsequent outgrowth are key factors that control the final shoot architecture. Some genes have been implicated in the control of initiation of axillary meristems as well as lateral bud formation and outgrowth. One example of such genes is the family of transcription factors squamosa (SQUA) promoter-binding-like proteins (SPL). SPLs genes are post-transcriptionally regulated by a family of microRNAs, the microRNA 156 (miR156). MicroRNAs are a class of small non-coding RNAs that regulate post-transcriptionally the expression of endogenous genes in eukaryotes. Interestingly, the overexpression of miR156 promotes severe reduction of apical dominance in Arabidopsis, leading to a greater production of lateral branches and increased plant biomass. However, the role of the miR156 and SPLs in lateral branching is not completely understood thus far. Moreover, there are no studies elucidating which lateral branching-related genetic pathways are regulated by the miR156/SPL pathway. Such studies could contribute not only to better understanding the mechanisms involved in the process of formation of lateral organs, but also have potential applications in plant breeding.