Project description:Salt stress is one of the most severe environmental conditions which cause huge losses in crop production worldwide. We identified an essential regulator of salt stress RSA3 and used the Affymetrix whole-genome arrays to study the effect of rsa3-1 mutation on global gene expression under salt stress. A set of genes differentially expressed in rsa3-1 under salt stress are identified.
Project description:Keeping imbibed seeds at low temperatures for a certain period, so called seed vernalization (SV) treatment, promotes seed germination and subsequent flowering in various plants. Vernalization-promoting flowering requires GSH. However, the expression patterns analyzed by GeneChip arrays showed that increased GSH biosynthesis partially mimics SV treatment in Arabidopsis thaliana. SV treatment (keeping imbibed seeds at 4°C for 24 h) induced a specific pattern of gene expression and promoted subsequent flowering in wild-type plants. A similar pattern was observed at 22°C in transgenic plants (35S-GSH1 plants) overexpressing the γ-glutamylcysteine synthetase gene GSH1, coding an enzyme limiting GSH biosynthesis, under the control of the cauliflower mosaic virus 35S promoter. This pattern was strengthened at 4°C but flowering was less responsive to SV treatment. There was a difference in the transcript behaviour of the flowering repressor FLC between wild-type and 35S-GSH1 plants. Unlike other genes responsive to SV treatment, SV-dependent decrease in FLC in wild-type plants was reversed in 35S-GSH1 plants. SV treatment increased GSSG level in wild-type seeds, whereas GSSG level was high in 35S-GSH1 plants, even at a non-vernalizing temperature. Taking into consideration that low temperatures stimulate GSH biosynthesis and bring about oxidative stress, GSSG is considered to trigger low temperature response, but enhanced GSH synthesis was not enough for mimicking SV treatment. To complete it, it essentially required the cellular redox retransition from the oxidized to the reduced state that is observed after the seed vernalization treatment.
Project description:Samples 1 & 2: Comparison of gene expression between wild type (ecotype Ler) and 35S:CUC1, in which CUP-SHAPED COTYLEDON1, a master regulator of the shoot meristem and boundary establishment, is constitutively expressed under the cauliflower mosaic virus 35S promoter. Samples 3 & 4: Comparison of gene expression between stm-1 (ecotype Ler) and stm-1 35S:CUC1
