Project description:We performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) wild type plants under phosphate starvation stress and in plants with altered PHR1(-like) activity, comparing mutants of phr1 and phr1-phl1 grown in phosphate-lacking medium. Results show the central role of PHR1 and functionally redundant members of its family in the control of transcriptional responses to Pi starvation.
Project description:Phosphate limitation constrains plant development in natural and agricultural systems. Under phosphate-limiting conditions plants activate genetic, biochemical and morphological modifications to cope with phosphate starvation. One of the morphological modifications that plants induce under phosphate limitation is the arrest of primary root growth and it is induced by the root tip contact with low phosphate media. The sensitive to proton rhizotoxicity (stop1) and aluminium activate malate transporter 1 (almt1) mutants of Arabidopsis thaliana continue primary root growth under in vitro Pi-limiting conditions, thus, to get insight into the molecular components that control primary root growth inhibition under low phosphate conditions we extracted and sequenced mRNA from the root tips (2-3 mm from the root apex) of wild-type plants (Col-0 accession) and low-phosphate-insensitive mutants almt1 and stop1 grown under low and high phosphate conditions 5 days after germination using an RNA-seq methodology.
Project description:SNF1 RELATED PROTEIN KINASE 1 (SnRK1) is proposed as a central integrator of regulatory pathways in plant stress and energy starvation signaling. We observed in this study that the Arabidopsis SnRK1.1 dominant negative mutant (SnRK1.1K48M) had lower tolerance to submergence than the wild-type, suggesting that SnRK1.1-dependent phosphorylation of target proteins is important in energy starvation signaling triggered by submergence. To gain further insight into submergence signaling mechanisms, we determined the temporal response to energy starvation through AMP/ATP quantification and used quantitative phosphoproteomics to compare the global changes in phosphopeptides in Col-0 and SnRK1.1K48M. We found that the phosphorylation levels of 59 peptides increased and the levels of 96 peptides decreased in Col-0 within 0.5�� h of submergence. Among the 59 peptides with increased phosphorylation in Col-0, 49 did not show increased phosphorylation levels in SnRK1.1K48M under submergence. These proteins are involved in sugar synthesis, glycolysis, osmotic regulation, ABA signaling, protein synthesis and ROS signaling. In particular, the phosphorylation of MAPK6, which is involved in regulating ROS responses under different abiotic stresses, was disrupted in the SnRK1.1K48M mutant. In addition, PTP1, a negative regulator of MAPK6 activity that directly dephosphorylates MAPK6, was also regulated by SnRK1.1. These results reveal insights into the function of SnRK1 and the downstream signaling factors of submergence.
Project description:SNF1 RELATED PROTEIN KINASE 1 (SnRK1) is proposed as a central integrator of regulatory pathways in plant stress and energy starvation signaling. We observed in this study that the Arabidopsis SnRK1.1 dominant negative mutant (SnRK1.1K48M) had lower tolerance to submergence than the wild-type, suggesting that SnRK1.1-dependent phosphorylation of target proteins is important in energy starvation signaling triggered by submergence. To gain further insight into submergence signaling mechanisms, we determined the temporal response to energy starvation through AMP/ATP quantification and used quantitative phosphoproteomics to compare the global changes in phosphopeptides in Col-0 and SnRK1.1K48M. We found that the phosphorylation levels of 59 peptides increased and the levels of 96 peptides decreased in Col-0 within 0.5–3 h of submergence. Among the 59 peptides with increased phosphorylation in Col-0, 49 did not show increased phosphorylation levels in SnRK1.1K48M under submergence. These proteins are involved in sugar synthesis, glycolysis, osmotic regulation, ABA signaling, protein synthesis and ROS signaling. In particular, the phosphorylation of MAPK6, which is involved in regulating ROS responses under different abiotic stresses, was disrupted in the SnRK1.1K48M mutant. In addition, PTP1, a negative regulator of MAPK6 activity that directly dephosphorylates MAPK6, was also regulated by SnRK1.1. These results reveal insights into the function of SnRK1 and the downstream signaling factors of submergence.
Project description:We examined the changes in gene expression in Arabidopsis thaliana grown under arsenate stress. The transcriptional profiling reveals antioxidant activity and repression of the phosphate starvation response. Keywords: dual label, stress response
Project description:This RNA-Seq analysis compares gene expression of the pho7∆ fission yeast (Schizosaccharomyces pombe) strain prior to phosphate starvation (0 HR), i.e. in phosphate replete conditions, and at various times after phosphate starvation (4, 8, 12, 24, 36, and 48 HR) contrasting to the WT fission yeast S. pombe cells grown in phosphate replete conditions (WT 0HR)
Project description:This RNA-Seq analysis compares gene expression of fission yeast (Schizosaccharomyces pombe) strains prior to phosphate starvation (0 HR) and at various times after phosphate starvation (4, 8, 12, 24, 36, and 48 HR) contrasting to the WT fission yeast S. pombe cells grown in phosphate replete conditions (WT 0HR)