Zea mays Transcriptome or Gene expression. Zea mays

This study looked for early response signals produced in UV-B irradiated leaves and induced in shielded leaves and shielded ears that modulate physiological responses in maize. Transcriptome profiling tracked changes in exposed and shielded organs. Metabolic profiling was examined for signaling molecules. The top 2 leaves were exposed to 10, 30, or 60 minutes of ~3x normal UV-B and then tissue samples were taken from all 3 tissue types. Over 250 transcripts are differentially expressed at least 2 fold in irradiated leaves by 10 min of UV-B. At 30 min this decreased to ~150 then increased to over 500 transcripts at 60 min. Different pathways are affected at the various time exposures and specific responses are modulated by the time of exposure. Shielded leaves had a smaller number of transcripts affected at each time point but over 60% were in common with the irradiated leaves results at 10 min. and ~20% overlaps were found at 30 and 60 min. Metabolite samples were analyzed after 5, 10, 15, 30, and 90 min of UV-B. We identified 14 compounds with a statistically significant change from untreated plants in at least one time point. Overall design: Compared transciptomes of irradiated leaves, shielded leaves, and shielded ears from plants whose top 2 leaves were exposed to ~3x normal UV-B for 10, 30, and 60 minutes.