The role of Populus MYB94 transcription factor in seed germination requires the expression of ABA-responsive genes

Plant seed germination is easily influenced by endogenous gene expression, hormones and environmental conditions. Here, we investigated a Populus R2R3-MYB transcription factor (referred to as MYB94) that plays a role in seed germination in close relation to the hormone abscisic acid (ABA). Two independent Arabidopsis transgenic lines overexpressing MYB94 (Oe-lines) and wild-type (Wt) were no clear differences in the seed germination rates under normal conditions, but the germination rates of the two Oe-lines were both significantly delayed under ABA treatment. This delay in germination is most likely associated with the endogenous hormone abscisic acid (ABA). We find that the transcript levels of several representative genes in relation to ABA synthesis or signaling in the MYB94 Oe-lines showed significantly increased compared with those of the Wt plants. Taken together, our results here reveal the role of the Populus R2R3-MYB transcription factor MYB94 in regulating the ABA-responsive genes in plant seed germination.