Project description:Innovative strategies for increasing the yield of rice, the staple food for more than half of the global population, are needed to keep pace with the expected worldwide population increase, and sustainably forefront the challenges posed by climate change. Traditionally, in Southern-East Asian countries, rice farming benefits from the use of Azolla spp., either as green manure or as co-cultivated plants, for the supply of nitrogen. Azolla spp. are ferns that, in virtue of their symbiosis with the nitrogen-fixing cyanobacterium Trichormus azollae, fix atmospheric nitrogen and release it to the environment upon decomposition of their biomass. However, if and to what extent actively growing Azolla plants impact on the development of co-cultivated rice plantlets remains to be understood. To address this point here we employed an experimental model to follow the growth and development of roots and aerial organs of rice seedlings when co-cultivated with Azolla filiculoides. We show that actively growing A. filiculoides plants alter the architecture of the roots, the transcriptome of the roots, and the hormonal profiles of both roots and leaves.
Project description:Microarray analysis to examine the relationship between hepatic phenotype and changes in gene expression in cytochrome P450 reductase (CPR) null mice. Keywords: ordered
Project description:The Saccharomyces cerevisiae Yap1p transcription factor is required for the H2O2-dependent activation of many antioxidant genes including the TRX2 gene encoding thioredoxin 2. To identify factors that regulate Yap1p activity, we carried out a genetic screen for mutants that show elevated expression of a TRX2-HIS3 fusion in the absence of H2O2. Two independent mutants isolated in this screen carried mutations in the TRR1 gene encoding thioredoxin reductase. Northern blot and whole-genome expression analysis revealed that the basal expression of most Yap1p targets and many other H2O2-inducible genes is elevated in Deltatrr1 mutants in the absence of external stress. In Deltatrr1 mutants treated with H2O2, the Yap1p targets, as well as genes comprising a general environmental stress response and genes encoding protein-folding chaperones, are hyperinduced. However, despite the elevated expression of genes encoding antioxidant enzymes, Deltatrr1 mutants are extremely sensitive to H2O2. The results suggest that cells lacking thioredoxin reductase have diminished capacity to detoxify oxidants and/or to repair oxidative stress-induced damage and that the thioredoxin system is involved in the redox regulation of Yap1p transcriptional activity.
