Project description:Post-transcriptional gene regulation plays a significant role in the response to Pi starvation. Here, we utilized advances in next-generation sequencing technology to examine changes in transcriptional control, RNA association with translating ribosomes in 14-day-old Arabidopsis seedlings subjected to 7 days of Pi starvation.
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:We report global gene expression profilies of Brassinosteroid related Arabidopsis mutants in response to dehydration and fixed-carbon starvation stresses by RNA-seq
Project description:Plants possess an enormous plasticity to adapt their metabolism to the fluctuating energy supply in a natural environment. Using dark-induced senescence (DIS) as an experimental system, a mutant study combining phenotypical, transcriptomic and Chromatin Immunoprecipitation Sequencing (ChIPseq) approaches identifies distinct members of the Arabidopsis group S1 basic leucine zipper transcription factors that orchestrate the starvation response. While excluding bZIP2, bZIP11 and bZIP44 to function in DIS, the in part redundantly acting bZIP1 and bZIP53 control a co-expression network governing amino acid catabolism and transport, gluconeogenesis and energy homeostasis. Moreover, they regulate genes involved in asparagine – glutamine balance, which are critical for C/N homeostasis. This transcriptional reprogramming in resource management is required for survival during starvation and regaining meristematic activity during recovery from stress. Thus, we provide insights into the transcriptional control of plant resource and energy management during starvation. Finally, this work sheds light on the discrepancy between in vitro DNA-binding and overexpression studies versus mutant analyses and in vivo DNA-binding, providing a critical view on how to define specific transcription factor functions within large families.
Project description:Renal gluconeogenesis accounts for half of systemic gluconeogenesis during starvation, but its regulatory mechanisms and implications in chronic kidney disease (CKD) remain unknown. In this study, using single-cell RNA sequencing of starved kidneys and various animal models, we aimed to identify key pathways involved in renal gluconeogenesis and their role in the development of hypoglycemia during starvation in diseased kidneys. Under the starvation condition, renal gluconeogenesis was highly induced in proximal tubule cells with FOXO1 activation. In renal tubular epithelial cells, starvation-induced FOXO1 activation was required to stimulate gluconeogenesis and promote glucose production. We further analyzed whether renal FOXO1-mediated gluconeogenesis is impaired in CKD. In CKD animal models, the kidneys exhibited reduced FOXO1 and gluconeogenic protein expression; however, serum glucose levels remained unchanged, suggesting that diminished renal gluconeogenesis does not significantly impact circulating glucose levels. When CKD mice were subjected to starvation, serum glucose levels were significantly reduced after 72 hours. In the CKD model, FOXO1 activation failed, accompanied by a lower induction of gluconeogenic protein expression. Similar to diseased condition, aged mice exposed to starvation also showed impaired gluconeogenic response in the kidney, contributing to reduced circulating glucose levels. Under the in vitro condition, we found that profibrotic TGFβ1 inhibits starvation-induced gluconeogenesis by directly suppressing the FOXO1 signaling pathway in tubular cells. Finally, we generated tubule-specific FOXO1 knockout (KO) mice by crossing FOXO1 floxed mice with Ksp-cre mice. These tubule-specific FOXO1 KO mice exhibited reduced expression of gluconeogenic genes in the kidney, leading to hypoglycemia during starvation. Collectively, we demonstrated crucial role of renal FOXO1 in gluconeogenesis during starvation, and its implication in kidney disease.
Project description:We investigated eisosome rearrangement during glucose starvation. Pil1 phosphorylation was assessed in control and starvation conditions.
Project description:We performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) phr1 mutant plants expressing PHR1 in presence of cicloheximide, that inhibit protein translation, thus preventing any effect of PHR1 on the expression of indirect targets. Results show the primary target genes of PHR1 in the responses to Pi starvation.
Project description:This SuperSeries is composed of the following subset Series: GSE33790: The response and recovery of Arabidopsis thaliana transcriptome to phosphate starvation [ATH1-121501] GSE33996: The response and recovery of Arabidopsis thaliana transcriptome to phosphate starvation [At35b_MR] Refer to individual Series