A large number of plant genes involved in plant stress response have been identified thus far on the basis of their up-regulation during stress, by differential screening, differential display or microarray analysis. Gene inducibility does not implicate necessarily that a specific gene is crucial for stress tolerance. However, comparing changes in plant gene expression in response to shock stress versus acclimation conditions is a valuable strategy to distinguish between genes involved in cell survival from those contributing to establish a new cellular homeostatis under stress. We have previously reported that gradual acclimation of potato cells to PEG-induced water stress allows active growth through a set of metabolic changes, including proline accumulation, de novo protein synthesis, changes in membrane lipid composition, not observed in cells exposed abruply to water stress (Plant Physiol 106: 703-712; Plant, Cell & Environ 19: 1103-1109). To have a global view of the changes in gene expression in response to water stress, the TIGR 10k potato array was challenged with RNA isolated from untreated, PEG-shocked and PEG-acclimated cells. The slides were hybrized, at least in six technical replicates, including dye swap, with labeled Cy3-dUTP and Cy5-dUTP retro-transcribed total RNA. A thorough statistical analysis of the output results revealed that more than 300 genes were up-regulated (>2.0 fold increase) belonging to different functional categories (including transcription factors, stress-proteins, amino-acid, protein and carbohydrate metabolism, cell wall synthesis and others) in both PEG-shocked and acclimated potato cells. However, only 13 cDNAs were common to both treatments. Similarly, a limited number (30) of common down-regulated genes were identified in the two cell populations. The contribution of specific gene functional classes in the acclimation or in the abrupt response to water stress will be discussed on the basis of the microarray results and their differential expression by RT-PCR or Real-time RT-PCR.
Differential gene regulation in potato cells upon abrupt or gradual acclimation to water stress
Costa A;
2005
Abstract
A large number of plant genes involved in plant stress response have been identified thus far on the basis of their up-regulation during stress, by differential screening, differential display or microarray analysis. Gene inducibility does not implicate necessarily that a specific gene is crucial for stress tolerance. However, comparing changes in plant gene expression in response to shock stress versus acclimation conditions is a valuable strategy to distinguish between genes involved in cell survival from those contributing to establish a new cellular homeostatis under stress. We have previously reported that gradual acclimation of potato cells to PEG-induced water stress allows active growth through a set of metabolic changes, including proline accumulation, de novo protein synthesis, changes in membrane lipid composition, not observed in cells exposed abruply to water stress (Plant Physiol 106: 703-712; Plant, Cell & Environ 19: 1103-1109). To have a global view of the changes in gene expression in response to water stress, the TIGR 10k potato array was challenged with RNA isolated from untreated, PEG-shocked and PEG-acclimated cells. The slides were hybrized, at least in six technical replicates, including dye swap, with labeled Cy3-dUTP and Cy5-dUTP retro-transcribed total RNA. A thorough statistical analysis of the output results revealed that more than 300 genes were up-regulated (>2.0 fold increase) belonging to different functional categories (including transcription factors, stress-proteins, amino-acid, protein and carbohydrate metabolism, cell wall synthesis and others) in both PEG-shocked and acclimated potato cells. However, only 13 cDNAs were common to both treatments. Similarly, a limited number (30) of common down-regulated genes were identified in the two cell populations. The contribution of specific gene functional classes in the acclimation or in the abrupt response to water stress will be discussed on the basis of the microarray results and their differential expression by RT-PCR or Real-time RT-PCR.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
