Project description:Plant responses to abiotic stresses are accompanied by massive changes in transcriptome composition. To provide a comprehensive view of stress-induced changes in the Arabidopsis thaliana transcriptome, we have used whole-genome tiling arrays to analyze the effects of salt, osmotic, cold and heat stress as well as application of the hormone abscisic acid (ABA), an important mediator of stress responses.
Project description:To investigate differences in plant responses to salt and ABA stimulus, differences in gene expression in Arabidopsis in response to salt and ABA were compared using an Agilent oligo microarray. Four-week-old Arabidopsis thaliana ecotype Columbia (Col-0) seedlings were treated with either 150 mM NaCl or 10 μM ABA for 6 hours; unstressed seedlings (control sample) were collected in parallel to avoid the possible effects of circadian rhythms. The results revealed that 31 genes were up regulated by both NaCl and ABA stress, and 23 genes were down-regulated by these stressors. To provide further validation of our microarray experiment data, ten genes from this signature were quantified in the same RNA samples by quantitative real-time PCR.
Project description:To investigate differences in plant responses to salt and ABA stimulus, differences in gene expression in Arabidopsis in response to salt and ABA were compared using an Agilent oligo microarray. Four-week-old Arabidopsis thaliana ecotype Columbia (Col-0) seedlings were treated with either 150 mM NaCl or 10 M-NM-<M ABA for 6 hours; unstressed seedlings (control sample) were collected in parallel to avoid the possible effects of circadian rhythms. The results revealed that 31 genes were up regulated by both NaCl and ABA stress, and 23 genes were down-regulated by these stressors. To provide further validation of our microarray experiment data, ten genes from this signature were quantified in the same RNA samples by quantitative real-time PCR. Differentially expression genes of Arabidopsis thaliana were measured under salt stressed, ABA stressed and normal condition for 6 hours, respectively. Three independent experiments were performed at each treatment using different plants for each experiment.
Project description:High salinity is one of the major environmental factors, which hampers plant growth, development and productivity. To better understand the regulatory mechanisms by which plants cope with salt stress, we used genetic approaches to identify salt hypersensitive mutant 9 (sahy9), a new allele of apum23, in Arabidopsis thaliana. The sahy9/apum23 mutant seedlings display postgemination developmental arrest and later become bleached under agar plates supplemented with various salt stressors. Transcriptomic and proteomic analyses of the salt-treated sahy9/apum23 and wild-type seedlings revealed differential expression of genes with similar functional categories, primarily including cellular and metabolic processes, and abiotic and biotic stress responses. However, the consistency of gene expression at both transcript and protein levels is low (), suggesting the involvement of posttranscriptional processing in salt response. Furthermore, the altered gene/protein expression mediated by SAHY9/APUM23 in salt sensitivity is involved in several functional groups, particularly in ABA biosynthesis and signaling, abiotic stress response, LEA proteins, and ribosome biogenesis-related genes. Importantly, NCED3, a key gene involved in ABA biosynthesis, and major ABA responsive marker genes, such as RD20 and RD29B, are down-regulated at both transcript and protein levels in sahy9/apum23 under salt stress. Consistently, lower contents of ABA and proline, and expression changes of a subset of LEA proteins also support the nature of sahy9/apum23 showing salt hypersensitivity. Collectively, these data suggest that SAHY9/APUM23-mediated salt response is associated with ABA signaling pathway and its downstream stress responsive or tolerant genes.
Project description:Plants physiological mechanisms are affected by Abscisic acid (ABA) via changing gene expression and empowers plants to adapt in numerous environments. Plants have evolved their protection mechanisms for seed germination and abiotic environments to deal with critical harsh conditions. Here, we have explored those changes in Arabidopsis thaliana plants subjected to multiple abiotic stresses. AtBro1 transcripts showed up-regulation in the presence of salt, ABA and mannitol stress conditions. AtBRO1 over-expression lines exhibited robust tolerance to drought and salt stress. Further, ABA elicits resistance responses in loss-of-function bro1-1 mutant plants and AtBro1 positively regulates drought resistance in Arabidopsis. Promoter of AtBro1 fused with GUS showed GUS expression mainly in the rosette leaves and floral clusters, especially in anthers. AtBro1 protein was found to be localized in the plasma membrane of Arabidopsis at the subcellular level by using AtBro1::GFP fusion. Using a broad RNA-sequencing analysis, we observed that early transcriptional responses prompted by ABA induction exhibit specific quantitative differences at different time points, suggesting that ABA stimulates resistance responses in bro1-1 mutant plants. Additionally, transcripts levels of MOP9.5, MRD1, HEI10, and MIOX4 were altered in loss-of-function mutant plants which are involved in different stress conditions. Collectively, our results have shown that AtBro1 is involved in a significant role by regulating plant transcriptional response to ABA and induction of resistance response against abiotic stress.
Project description:this study discovered unique glycoprotein resources responsible for plant salt stress tolerance and suggested crucial roles of Nthis study discovered unique glycoprotein resources responsible for plant salt stress tolerance and suggested crucial roles of N-glycans in regulating salt responsive protein expression in Arabidopsis.-glycans in regulating salt responsive protein expression in Arabidopsis.
Project description:Several nucleoporins in the nuclear pore complex (NPC) have been reported to be involved in abiotic stress responses in plants. However, the molecular mechanism of how NPC regulates abiotic stress responses, especially the expression of stress responsive genes remains poorly understood. From a forward genetics screen using an abiotic stress-responsive luciferase reporter (RD29A-LUC) in the sickle-1 (sic-1) mutant background, we identified a suppressor caused by a mutation in NUCLEOPORIN 85 (NUP85), which exhibited reduced expression of RD29A-LUC in response to ABA and salt stress. Consistently, the ABA and salinity induced expression of several stress responsive genes such as RD29A, COR15A and COR47 was significantly compromised in nup85 mutants and other nucleoporin mutants such as nup160 and hos1. Subsequently, Immunoprecipitation and mass spectrometry analysis revealed that NUP85 is potentially associated with HOS1 and other nucleoporins within the nup107-160 complex, along with several mediator subunits. We further showed that there is a direct physical interaction between MED18 and NUP85. Similar to NUP85 mutations, MED18 mutation was also found to attenuate expression of stress responsive genes. Taken together, we not only revealed the involvement of NUP85 and other nucleoporins in regulating ABA and salt stress responses, but also uncovered a potential relation between NPC and mediator complex in modulating the gene expression in plants.
Project description:Arabidopsis ecotypes of Sha and Ler showed differences in tolerance to salinity stress. A previous study indicated that a premature stop codon resulting in a truncated Response to ABA and Salt 1 (RAS1) protein in Sha contributes to the increased salt tolerance relative to Ler ecotype. Sha exhibited higher germination rates and longer roots on MS plate, presumably due to the decreased ABA sensitivity in Sha. More Sha plants also survived in soil after salt treatment with relatively lower electrolyte leakage when compared to Ler. Transcriptome analysis revealed that expression levels of many genes were changed between Sha and Ler ecotypes and by salt treatments. About 500 transcripts were commonly changed by at least one salinity effect and one ecotype effect, and 171 of them were co-regulated by all four comparisons. Transcripts involved in redox, secondary metabolism, auxin metabolism, photosynthesis, cell wall, and protein synthesis were mainly down-regulated by salinity effects, while transposable element genes, microRNA and antisense sequences, histone superfamily genes, and biotic stress related genes were significantly changed by Sha ecotype effects and only slightly by salinity. Several metabolic pathways such as stress, TCA, hormone/lipid/secondary metabolism, redox, development, and GO terms involved in stress, oxidation, and defense response were enriched by both salinity and ecotype effects. Ninety-five highly inducible genes were identified as candidates of RAS1 target genes and the functions involved hormone metabolism, biotic stress, RNA, DNA synthesis, protein metabolism, cell, and microRNA metabolism. All these results indicated that the Sha ecotype was possibly preconditioned to abiotic stress relative to Ler through regulation of signaling pathways and stress responsive gene expression. These comparative transcriptomic and analytical results also confirm the complexity of ABA responses and salt stress tolerance mechanisms, and they suggest additional targets for improving tolerance. Ten days old seedlings of two Arabidopsis ecotypes, Sha and Ler, were treated with 100 mM NaCl on MS plate. Plant materials were collected for RNA extraction at 4th days after treatments.
Project description:bHLH122 could be induced by salt, osmotic and drought stress except ABA, the transgentic Arabidopsis were more tolerant to abiotic stresses, such as drought and salt. What's more, in the overexpression plants, the endogenesis ABA contents were higher than WT. We found there existed an interaction between bHLH122 and CYP707A3 by virtue of EMSA and ChIP assays. We wanted to learn more about the molecular mechanism of bHLH122 and to explore what had changed in the over-expression plant through Genechips.