Photoperiod associated genes in the poplar bark

The role of bark storage proteins (BSPs) in seasonal N storage and cycling has been well documented. However, the regulatory mechanisms and pathways associated with this physiological process are poorly understood. The objective of this study is to investigate global patterns of gene expression associated with photoperiod regulated BSP accumulation and to identify candidate genes, pathways and regulatory factors governing N storage and cycling in poplar. In this study, differential expression of protease inhibitors, proteases, transcription factors, and other genes coincided with increased BSP gene expression, suggesting a complex regulatory network that might play an important role in BSP accumulation. Bark of Populus trichocarpa (Nisqually-1) was collected at weekly intervals for 6 weeks from plants treated with short-day (SD) photoperiods at 20°C as well as from long-day (LD) grown plants immediately before the SD treatment.