Transcriptome analysis reveals coordinated spatiotemporal regulation of hemoglobin and nitrate reductase in response to nitrate in maize roots
Article first published online: 15 JUL 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 192, Issue 2, pages 338–352, October 2011
How to Cite
Trevisan, S., Manoli, A., Begheldo, M., Nonis, A., Enna, M., Vaccaro, S., Caporale, G., Ruperti, B. and Quaggiotti, S. (2011), Transcriptome analysis reveals coordinated spatiotemporal regulation of hemoglobin and nitrate reductase in response to nitrate in maize roots. New Phytologist, 192: 338–352. doi: 10.1111/j.1469-8137.2011.03822.x
- Issue published online: 27 SEP 2011
- Article first published online: 15 JUL 2011
- Received: 24 March 2011, Accepted: 6 June 2011
- cDNA-amplified fragment length polymorphism (AFLP);
- hemoglobin (HB);
- mRNA localization;
- nitrate (NO3−) sensing;
- nitrate reductase (NR);
- nitric oxide (NO);
- Zea mays (maize)
- •Given the importance of nitrogen for plant growth and the environmental costs of intense fertilization, an understanding of the molecular mechanisms underlying the root adaptation to nitrogen fluctuations is a primary goal for the development of biotechnological tools for sustainable agriculture. This research aimed to identify the molecular factors involved in the response of maize roots to nitrate.
- •cDNA-amplified fragment length polymorphism was exploited for comprehensive transcript profiling of maize (Zea mays) seedling roots grown with varied nitrate availabilities; 336 primer combinations were tested and 661 differentially regulated transcripts were identified. The expression of selected genes was studied in depth through quantitative real-time polymerase chain reaction and in situ hybridization.
- •Over 50% of the genes identified responded to prolonged nitrate starvation and a few were identified as putatively involved in the early nitrate signaling mechanisms. Real-time results and in situ localization analyses demonstrated co-regulated transcriptional patterns in root epidermal cells for genes putatively involved in nitric oxide synthesis/scavenging.
- •Our findings, in addition to strengthening already known mechanisms, revealed the existence of a new complex signaling framework in which brassinosteroids (BRI1), the module MKK2–MAPK6 and the fine regulation of nitric oxide homeostasis via the co-expression of synthetic (nitrate reductase) and scavenging (hemoglobin) components may play key functions in maize responses to nitrate.