INVESTIGADORES
CASATI Paula
artículos
Título:
Rapid transcriptome responses of maize to UV-B in irradiated and shielded tissues
Autor/es:
PAULA CASATI; VIRGINIA WALBOT
Revista:
GenomeBiology.com (London. Print)
Referencias:
Año: 2004 vol. 5 p. 1 - 1
ISSN:
1465-6906
Resumen:
Background: Depletion of stratospheric ozone has raised terrestrial levels of ultraviolet-B
radiation (UV-B), an environmental change linked to an increased risk of skin cancer and with
potentially deleterious consequences for plants. To better understand the processes of UV-B
acclimation that result in altered plant morphology and physiology, we investigated gene
expression in different organs of maize at several UV-B fluence rates and exposure times.Depletion of stratospheric ozone has raised terrestrial levels of ultraviolet-B
radiation (UV-B), an environmental change linked to an increased risk of skin cancer and with
potentially deleterious consequences for plants. To better understand the processes of UV-B
acclimation that result in altered plant morphology and physiology, we investigated gene
expression in different organs of maize at several UV-B fluence rates and exposure times.
Results: Microarray hybridization was used to assess UV-B responses in directly exposed maize
organs and organs shielded by a plastic that absorbs UV-B. After 8 hours of high UV-B, the
abundance of 347 transcripts was altered: 285 were increased significantly in at least one organ and
80 were downregulated. More transcript changes occurred in directly exposed than in shielded
organs, and the levels of more transcripts were changed in adult compared to seedling tissues. The
time course of transcript abundance changes indicated that the response kinetics to UV-B is very
rapid, as some transcript levels were altered within 1 hour of exposure.Microarray hybridization was used to assess UV-B responses in directly exposed maize
organs and organs shielded by a plastic that absorbs UV-B. After 8 hours of high UV-B, the
abundance of 347 transcripts was altered: 285 were increased significantly in at least one organ and
80 were downregulated. More transcript changes occurred in directly exposed than in shielded
organs, and the levels of more transcripts were changed in adult compared to seedling tissues. The
time course of transcript abundance changes indicated that the response kinetics to UV-B is very
rapid, as some transcript levels were altered within 1 hour of exposure.
Conclusions: Most of the UV-B regulated genes are organ-specific. Because shielded tissues,
including roots, immature ears, and leaves, displayed altered transcriptome profiles after exposure
of the plant to UV-B, some signal(s) must be transmitted from irradiated to shielded tissues. These
results indicate that there are integrated responses to UV-B radiation above normal levels. As the
same total UV-B irradiation dose applied at three intensities elicited different transcript profiles,
the transcriptome changes exhibit threshold effects rather than a reciprocal dose-effect response.
Transcriptome profiling highlights possible signaling pathways and molecules for future research.Most of the UV-B regulated genes are organ-specific. Because shielded tissues,
including roots, immature ears, and leaves, displayed altered transcriptome profiles after exposure
of the plant to UV-B, some signal(s) must be transmitted from irradiated to shielded tissues. These
results indicate that there are integrated responses to UV-B radiation above normal levels. As the
same total UV-B irradiation dose applied at three intensities elicited different transcript profiles,
the transcriptome changes exhibit threshold effects rather than a reciprocal dose-effect response.
Transcriptome profiling highlights possible signaling pathways and molecules for future research.