Project description:Sequence-specific transcription factor WRKY75 is highly responsive to reactive oxygen species on transcriptional level in the rosettes of Arabidopsis thaliana. In addition, it acts in developmental responses, acquisition of nutrients, and in stress responses. In the root, WRKY75 is a repressor of root hair formation, it regulates the phosphate starvation response, and the response to certain pathogens. In order to find the target genes of WRKY75, the effects of estradiol-inducible overexpression of WRKY75 on transcriptome was studied using RNA-seq. Two independent inducible WRKY75 overexpressor lines (N2102362 and N2102363) were treated with estradiol for 3 hours and four biological replicates, five plant per replicate, were used for RNA-seq. As a control, wild type Col-0 was treated with estradiol or water for 3 hours and three biological replicates, five plant per replicate, were used for RNA-seq.
Project description:In order to dissect the roles of sequence-specific transcription factors WRKY25, WRKY33 and WRKY75 in apoplastic ROS signaling, a transcriptome profiling of ozone response was done using two arabidopsis mutants: a double mutant wrky25 wrky33 and a single mutant wrky75. The single mutant lines used for transcriptomic analyses were obtained from NASC: wrky25 (SAIL_529_B11) and wrky33 (SALK_006603) were crossed to generate double mutant wrky25 wrky33. T-DNA insertion mutant wrky75-25 (N121525) was obtained from NASC. Three biological replicates, five plants per replicate, treated with 350 ppb ozone for 2 hours, were used for RNA-seq analysis. For each genotype, also non-ozone-treated samples were collected. For the Col-0 control line, an additional fourth replicate with/without ozone was done.
Project description:The formation of Reactive oxygen species (ROS) has been detected in all cellular departments and even in apoplastic space of plants. As multifaceted molecule, ROS are known to accumulate in response to various stresses, and ROS burst accompanied with transcriptomic reprogramming leading to defense response or programmed cell death. Acute ozone exposure has been used as a noninvasive tool to study ROS burst induced defense response and cell death for a long time. Moreover the variation of ozone sensitivity in different Arabidopsis accessions highlights the flexibility of complex genetic architecture to adapt to specific stresses. In this study, we combine classic Quantitative Trait Loci (QTL) mapping and RNA-seq to identify the cause QTLs and potential gene candidates in response to ozone. RNA sequencing was performed on both control and ozone treated 3 weeks old accessions C24 (ozone tolerant), Te (ozone sensitive) and on a RIL line CT101 (a hypersensitive line of RIL population from reciprocal cross between C24 and Te), in triplicate. We identified 69 potential genes candidates inside the QTL regions and about 200 potential genes outside QTL region in response to ozone by comparing control to treatment within same genotype or comparing control between genotypes. Transcriptome profiling of ozone response using two arabidopsis accessions C24 and Te with different ozone sensitivity
Project description:As sessile organism, plants evolved a highly complicated signaling system to cope with unfavorable and fluctuating environmental conditions. Rapid and transient Reactive Oxygen Species (ROS) burst is a common response to both biotic and abiotic stresses. Plants exposed with O3 could trigger extracellular similar ROS production through cell wall peroxidases and NPADPH oxidases, resulting in changes in the gene expression and cell death. Whereas ROS induced cell death is not simply due to its toxicity, rather due to interplay with several other signaling pathways, such as salicylic acid (SA), jasmonic acid (JA) and ethylene signaling pathways. Furthermore, the three hormones have both synergistic and antagonistic interactions, where the suppression of JA signaling by SA is the mostly studied. In addition, ethylene promotes cell death while JA has a protective role upon O3 exposure. The role of SA is more complicated; depending on the genetic background it can have either cell death promoting or protecting roles. Hence, a clean system to deliver apoplastic ROS is required to study the role of ROS apart from con-current activation of other signaling pathways. Arabidopsis thaliana offer a convenient system to study apoplastic ROS signaling due to the availability of hormone signaling or biosynthesis mutants including the JA receptor mutant coi1-16 (CORONATINE INSENSITIVE1), the essential ethylene signaling mutant ein2 (ETHYLENE INSENSITIVE2), the SA biosynthesis mutant sid2 (SALICYLIC ACID INDUCTION DEFICIENT2 also known as ISOCHORISMATE SYNTHASE1), and essential regulators in SA/JA/ethylene-induced defense response triple mutant tga2 tga5 tga6 (Clade II TGA transcription factors). Here we used a combination of transcriptome analysis, cell death assays and mutant analysis to systematically quantified the contribution of hormone signaling in relation to apoplastic ROS signaling, identified transcription factors (TFs) involved in ROS regulation and dissected the components involved in defense hormones associated cell death. Transcriptome profiling of ozone response using two arabidopsis triple mutants coi1-16 ein2 sid2 and tga2 tga5 tga6 related to Jasmonic acid, salicylic acid and ethylene signaling to identify hormone-independant apoplastic ROS signaling
Project description:Trees establish a symbiotic relationship with specialized soil fungi, called ectomycorrhizae, which is essential for nutrition, growth and health of temperate forest ecosystems. Understanding the mechanisms governing the establishment and functioning of ectomycorrhiza is important because of the role of forests in sequestering CO2 and also to develop ways to optimize tree productivity and sustainability. Here, we investigated the response of an oak species to ectomycorrhiza formation using a two dimensional differential in gel electrophoresis (2D-DIGE) and MALDI-TOF/TOF mass spectrometry proteomics approach. At the root level, changes in the abundance of 34 unique oak proteins were detected and revealed proteins involved in carbon and energy metabolism, protein processing and degradation, response to oxidative stress, lipid metabolism/transport, nitrogen and phosphorous assimilation and cell wall modification. Proteins supporting the importance of the secretory pathway functioning, in particular of the endoplasmic reticulum, during ectomycorrhiza functioning were identified. These proteins were identified as components of the endoplasmic reticulum folding/chaperoning machinery and proteins involved in the ER quality control system. This study constitutes an important contribution for the understanding of the mechanisms underlying the response of plants to ectomycorrhizal symbiosis establishment.
Project description:Salt stress causes the quality change and significant yield loss of tomato. However, the resources of salt-resistant tomato were still deficient and the mechanisms of tomato resistance to salt stress were still unclear. In this study, the proteomic profiles of two salt-tolerant and salt-sensitive tomato cultivars were investigated to deciphered the salt-resistance mechanism of tomato and provide novel resources for tomato breeding. We found that there is an over-abundant proteins relevant to Nitrate and amino acids metabolisms in the Salt-tolerant cultivars. The significant increase in expression of proteins involved in Brassinolides and GABA biosynthesis were verified in salt-tolerant cultivars, strengthening the salt resistance of tomato. Meanwhile, salt-tolerant cultivars with higher abundance and activity of antioxidant-related proteins have more advantages in dealing with reactive oxygen species caused by salt stress. And the salt-tolerant cultivars had higher photosynthetic activity based on overexpression of proteins functioned in chloroplast, guaranteeing the sufficient nutrient for plant growth under salt stress. Furthermore, three key proteins were identified as important salt-resistant resources for breeding salt-tolerant cultivars, including Sterol side chain reductase, gamma aminobutyrate transaminase and Starch synthase. Our results provided series valuable strategies for salt-tolerant cultivars which can be used in future
Project description:We present a functional characterisation of two members of the IDA-LIKE (IDL) peptide family in Arabidopsis thaliana, IDL6 and IDL7. They are processed both C- and N-terminally to produce active peptides. Structure analyses of synthesized IDL6 and IDL7 peptides indicate that they lack secondary structure elements. Localisation studies suggest that the peptides require a signal peptide and C-terminally processing to be correctly transported out of the cell. Treatment of plants with synthetic IDL6 and IDL7 peptides resulted in down-regulation of a broad range of stress-responsive genes, including early stress-responsive transcripts, dominated by a large group of ZINC FINGER PROTEINS (ZFPs), WRKYs and genes encoding calcium-dependent proteins. idl6 and idl7 mutants were more tolerant to salt, whereas the respective overexpression lines displayed increased sensitivity to both salt and oxidative stress. Taken together, our results suggest that the putative peptide ligands IDL6 and IDL7 act as suppressors of abiotic stress responses in Arabidopsis. Two weeks old seedlings were treated either with 100 nM IDL6 or IDL7 peptide (treated) or 100 nM mock peptide (control) and whole rosettes were harvested 2 hours after treatment. 4 biological replicaes per treatment. Two color microarray. Biological replicas are dye-swapped between slides.
Project description:72 plants have been grown in 2 phytochambers for 30 days under control temperature (21°C/19°C) and short day conditions (8 hours light/16 hours darkness). After 30 days the plants were switched to long day conditions (16 hours light/8 hours darkness) and the temperature of one phytochamber was increased to 29°C/27° (heat chamber). Moreover,a heatplate was located in the control chamber and a coldplate was located in the heat chamber. 18 plants have been grown on the heatplate with a constant temperature of 29°C. 18 plants have been grown on the coldplate with a constant temperature of 22°C. After 9 days of the heat period leaf samples (end of night) were taken for micorarray analysis. After 10 days of heat, tuber samples were taken for microarray analysis.
Project description:Macromolecular trafficking and cell-to-cell communication in plants occurs via plasmodesmata (PD). Currently, little is known about the proteins defining these sophisticated cell-to-cell contacts. To uncover proteins required for PD structure and function we made use of the 17 kDa movement protein (MP17) of the Potato leafroll virus (PLRV). The protein is required for cell-to-cell movement of the virus and localizes specifically to branched PD in source tissues. By forward genetic screening for Arabidopsis mutants with altered PD binding of MP17, several mutants were found. Map-based cloning of one of these mutants revealed a mutation in the choline transporter-like 1 (CHER1) protein. The mutation abolished plasma membrane localization of the protein. As consequence phosphatidylcholine levels and PD binding of MP17 decreased. Transcriptome analysis revealed a down-regulation of defense genes and genes involved in the synthesis of very long chain fatty acids, indicating an impairment of lipid signaling. Furthermore, cher1 mutants showed a reduced assimilate export and stunted growth. These findings highlight the emerging role of phospholipids, especially in the context of PD structure and function as well as potential binding sites for plasma membrane- and PD-associated proteins, which has been neglected for a long time. light exposed source leaves from wild type Col-0, T-DNA insertion line cher1-4 and mutant cher1-5 (10 weeks old). Samples: per pool 2 source leaves from 4 different plants, taken in the afternoon; wildtype (WT): Col-0, cher1-4: T-DNA insertion line SALK-065853 (ecotype Col-0, kanamycin resistance), cher1-5: Col-0 with GGA -->GAA at position 740 of cds
Project description:Floral organs, whose identity is determined by specific combinations of homeotic genes, originate from a group of undifferentiated cells called the floral meristem. In Arabidopsis, the homeotic gene AGAMOUS (AG) terminates meristem activity and promotes development of stamens and carpels. To understand the program of gene expression activated by AG, we followed genome-wide expression during early stamen and carpel development. Experiment Overall Design: Described in Gomez-Mena et al, 2005, Development 132: 429-438. Briefly, synchronous development of stamens and carpels was initiated by steroid treatment of plants homozygous for the ap1-1 and cal-1 mutations and expressing a fusion between AGAMOUS and the rat glucocorticoid receptor (35S:AGGR). RNA was extracted one, three and seven days after steroid treatment; two independent steroid-treated samples and two independent untreated controls were used for each time point.