Towards integrating the AHL transcription factors into a plant growth gene regulatory network

点击翻译按钮获取中文摘要

My work during the past funding period has provided new insights into the mechanisms by which the AHL transcription factors regulate transcription and growth in Arabidopsis. Together with my collaborators at Washington State University, I finished generating data for and writing a manuscript that describes how AHLs regulate gene expression and suppress hypocotyl growth in seedlings grown in short days. We recently resubmitted this manuscript to BMC Plant Biology, where it has been provisionally accepted. In this manuscript, we describe how AHLs affect the expression of different sets of genes at different times throughout the course of a short day. For example, we showed that SOB3 and/or other AHLs repress the expression of the PIF-activated, growth-promoting genes XTR7 and CDF5 at ZT9 and ZT24, but not at ZT4. On the other hand, we found that SOB3 and/or other AHLs activate the expression of the growth-repressing genes HY5, BBX22, RGA, and PRR9 specifically at ZT4. However, we unexpectedly also found that SOB3 exhibits similar patterns of binding to target genes at ZT4, ZT9, and ZT24. Thus, our data from this study collectively suggest that AHLs affects gene expression in a time-point specific manner irrespective of changes in binding to DNA throughout short days. Apart from work related to the BMC Plant Biology manuscript, I have also recently generated data suggesting that AHLs affect PIF activity at the protein level, i.e. they can reduce PIF-mediated activation of target genes without affecting PIF protein levels.