HFR1 Is Crucial for Transcriptome Regulation in the Cryptochrome 1-Mediated Early Response to Blue Light in Arabidopsis thaliana

Cryptochromes are blue light photoreceptors involved in development and circadian clock regulation. They are found in both eukaryotes and prokaryotes as light sensors. Long Hypocotyl in Far-Red 1 (HFR1) has been identified as a positive regulator and a possible transcription factor in both blue and far-red light signaling in plants. However, the gene targets that are regulated by HFR1 in cryptochrome 1 (cry1)-mediated blue light signaling have not been globally addressed. We examined the transcriptome profiles in a cry1- and HFR1-dependent manner in response to 1 hour of blue light. Strikingly, more than 70% of the genes induced by blue light in an HFR1-dependent manner were dependent on cry1, and vice versa. High overrepresentation of W-boxes and OCS elements were found in these genes, indicating that this strong cry1 and HFR1 co-regulation on gene expression is possibly through these two cis-elements. We also found that cry1 was required for maintaining the HFR1 protein level in blue light, and that the HFR1 protein level is strongly correlated with the global gene expression pattern. In summary, HFR1, which is fine-tuned by cry1, is crucial for regulating global gene expression in cry1-mediated early blue light signaling, especially for the function of genes containing W-boxes and OCS elements

The effects of conditioning strawberry plug plants under altered red/far red light environment on subsequent performance

The effect of altered red/far red light environment on subsequent field performance of strawberry plug plants was tested over two seasons. Two wavelength-selective plastic films were compared to neutral shade and full-sun control for conditioning \u27Chandler\u27 strawberry plug plants prior to transplanting to a winter production system. The following year, plug plants of \u27Chandler\u27, \u27Sweet Charlie\u27 and \u27Allstar\u27 were conditioned under the same treatments, with the addition of a continuous incandescent light and a short-day photoperiod. During the first year, the red light-filtering film slightly advanced flowering. During the second season however, the short-day treatment resulted in a greater reduction in runnering and increased early crown and flower development. For June-bearing strawberry plants maintained above 20\u27C, altering the red/far red environment did not consistently advance flowering