T-DNA-activation-tagging mutagenesis to identify determinants of abiotic stress response in Thellungiella halophila and Arabidopsis thaliana

Environmental stresses such as salinity and extreme temperatures negatively affect germination, growth and productivity of crops worldwide. To identify genes involved in abiotic stress tolerance, we carried out a large scale screening of T-DNA activation tagged mutants with stress-tolerant extremophile Thellungiella halophila (SHANGDONG, a halophyte) and model plant Arabidopsis thaliana (Col-0, a glycophyte) carrying a stress responsive TCH4 promoter fused luciferase (TCH4::LUC) reporter gene. Biochemical, genetic and molecular characterization of several mutants revealed several known and novel genes involved in plant development and stress signaling, e.g. HGC1 and CET1. T. halophila hgc1-1 (high germination capacity line 1) mutant showed decreased sensitivity to NaCl, mannitol and ABA during germination. HGC1 encodes a putative pyruvate kinase. The hgc1-1 mutant accumulates higher levels of HGC transcripts compared to wild type plants. A knock-out mutant of A. thaliana AtHGC1 (homolog of ThHGC1) exhibited hypersensitivity to NaCl and ABA during germination. Arabidopsis transgenic plants overexpressing AtHGC1 phenocopied the T. halophila hgc1-1 mutant in seed germination on media containing NaCl and ABA. Conservation of these gene sequences that maintain similar function in both the halophyte and glycophyte may be indicative that HGC1 is critical to the fitness of T. halophila to its native saline environment. TCH4::LUC reporter genetic screening led to the identification of cet1-1 (constitutively expression of TCH4::LUC) mutant, which showed constitutive expression of LUC. Northern blot revealed that endogenous TCH4 gene expression was higher in cet1-1 as compared with wild type plants. cet1-1 mutation resulted in morphological changes and enhanced thermotolerance. One of the reasons for increased heat tolerance of cet1-1 appears to be higher expression levels of HSP101 which encodes a necessary heat shock protein for thermotolerance. CET1 is an unknown gene and encodes a protein with unknown properties, and expresses in a wide range of tissues and developmental stages

Increasing Freezing Tolerance: Kinase Regulation of ICE1

Cold temperatures trigger the ICE1-CBF-COR transcriptional cascade in plants, which reprograms gene expression to increase freezing tolerance. In this issue of Developmental Cell, Ding et al. (2015) report that cold stress activates the protein kinase OST1 to phosphorylate and thereby stabilize and stimulate ICE1. This enhances plant tolerance to freezing temperatures

Two Triacylglycerol Lipases Are Negative Regulators of Chilling Stress Tolerance in Arabidopsis

Cold stress is one of the abiotic stress conditions that severely limit plant growth and development and productivity. Triacylglycerol lipases are important metabolic enzymes for the catabolism of triacylglycerols and, therefore, play important roles in cellular activities including seed germination and early seedling establishment. However, whether they play a role in cold stress responses remains unknown. In this study, we characterized two Arabidopsis triacylglycerol lipases, MPL1 and LIP1 and defined their role in cold stress. The expression of MPL1 and LIP1 is reduced by cold stress, suggesting that they may be negative factors related to cold stress. Indeed, we found that loss-of-function of MPL1 and LIP1 resulted in increased cold tolerance and that the mpl1lip1 double mutant displayed an additive effect on cold tolerance. We performed RNA-seq analysis to reveal the global effect of the mpl1 and lip1 mutations on gene expression under cold stress. The mpl1 mutation had a small effect on gene expression under both under control and cold stress conditions whereas the lip1 mutation caused a much stronger effect on gene expression under control and cold stress conditions. The mpl1lip1 double mutant had a moderate effect on gene expression under control and cold stress conditions. Together, our results indicate that MPL1 and LIP1 triacylglycerol lipases are negative regulators of cold tolerance without any side effects on growth in Arabidopsis and that they might be ideal candidates for breeding cold-tolerant crops through genome editing technology

Identification, Classification, and Expression Analysis of the <i>Triacylglycerol Lipase</i> (<i>TGL</i>) Gene Family Related to Abiotic Stresses in Tomato

Triacylglycerol Lipases (TGLs) are the major enzymes involved in triacylglycerol catabolism. TGLs hydrolyze long-chain fatty acid triglycerides, which are involved in plant development and abiotic stress responses. Whereas most studies of TGLs have focused on seed oil metabolism and biofuel in plants, limited information is available regarding the genome-wide identification and characterization of the TGL gene family in tomato (Solanum lycopersicum L.). Based on the latest published tomato genome annotation ITAG4.0, 129 SlTGL genes were identified and classified into 5 categories according to their structural characteristics. Most SlTGL genes were distributed on 3 of 12 chromosomes. Segment duplication appeared to be the driving force underlying expansion of the TGL gene family in tomato. The promoter analysis revealed that the promoters of SlTGLs contained many stress responsiveness cis-elements, such as ARE, LTR, MBS, WRE3, and WUN-motifs. Expression of the majority of SlTGL genes was suppressed following exposure to chilling and heat, while it was induced under drought stress, such as SlTGLa9, SlTGLa6, SlTGLa25, SlTGLa26, and SlTGLa13. These results provide valuable insights into the roles of the SlTGL genes family and lay a foundation for further functional studies on the linkage between triacylglycerol catabolism and abiotic stress responses in tomato

Identification, Classification, and Expression Analysis of the Triacylglycerol Lipase (TGL) Gene Family Related to Abiotic Stresses in Tomato

Triacylglycerol Lipases (TGLs) are the major enzymes involved in triacylglycerol catabolism. TGLs hydrolyze long-chain fatty acid triglycerides, which are involved in plant development and abiotic stress responses. Whereas most studies of TGLs have focused on seed oil metabolism and biofuel in plants, limited information is available regarding the genome-wide identification and characterization of the TGL gene family in tomato (Solanum lycopersicum L.). Based on the latest published tomato genome annotation ITAG4.0, 129 SlTGL genes were identified and classified into 5 categories according to their structural characteristics. Most SlTGL genes were distributed on 3 of 12 chromosomes. Segment duplication appeared to be the driving force underlying expansion of the TGL gene family in tomato. The promoter analysis revealed that the promoters of SlTGLs contained many stress responsiveness cis-elements, such as ARE, LTR, MBS, WRE3, and WUN-motifs. Expression of the majority of SlTGL genes was suppressed following exposure to chilling and heat, while it was induced under drought stress, such as SlTGLa9, SlTGLa6, SlTGLa25, SlTGLa26, and SlTGLa13. These results provide valuable insights into the roles of the SlTGL genes family and lay a foundation for further functional studies on the linkage between triacylglycerol catabolism and abiotic stress responses in tomato

Emergency planning within the Integrated Rescue System with focus on the activities of Police of the Czech Republic

Subject: Emergency planning within the Integrated Rescue Systém with focus on the activities of Police of the Czech Republic Objective: unify and define the legislation relating to the emergency planning with a focus on the service performance of the Czech Police and implement subsequently relevant legal standards into the tactical exercises "The Island 2011" in order to verify the practical set of principles, mechanisms with the possibilities of their evaluation based on real use. Method applied: research, classification and study of available sources, consultaion with the experts in the subject above, detailed analysis of the carried out exercises. Outcome: Based on the study of legislative norms indicating the framework of activities of individual components of Integrated Rescue Systém, consulting the respective variants of implementation of practical knowledge, as a result, the exercise was designed in order to verify the ability of the police management to manage and control the forces and resources during the performance of the police tasks and also to verify the practical ability of police Officers to perform set tasks and cooperate in the place of intervention with units and relevant agencies. Key words: Integrated Rescue Systém, crisis management, emergency planning, tipical aktivity,..

Additional file 2: Table S2. of De novo assembly and analysis of the transcriptome of Ocimum americanum var. pilosum under cold stress

Similarities between O. americanum var. pilosum and other species. (XLS 70 kb)

The tomato 2-oxoglutarate-dependent dioxygenase gene SlF3HL is critical for chilling stress tolerance

Chill stress: Gene regulator identified in tomato plants A gene involved in regulating responses to chill stress in tomato plants may prove valuable in reducing crop damage caused by low temperatures. A significant limiting factor in growing certain crops is cold stress – for example, tomato and cucumber plants suffer chill damage and reduced productivity at low temperatures (0 to 12 °C). Xianggiang Zhan at the Northwest A&F University in Shaanxi, China, and co-workers demonstrated that the gene SIF3HL is a key regulator of chilling stress tolerance in tomato plants. The team generated plants with no SIF3HL expressed and found that they responded poorly at low temperatures, with higher levels of reactive oxygen species and decreased levels of metabolic enzymes. Expression levels of four cold-responsive genes were also reduced. Plants overexpressing SIF3HL, on the other hand, coped well at low temperatures

Additional file 3: Table S3. of De novo assembly and analysis of the transcriptome of Ocimum americanum var. pilosum under cold stress

Pathways annotated by KEGG analysis. (XLS 221 kb)