Project description:Crop plants are often exposed to the combination of drought and pathogen stress. Transcriptome studies on Arabidopsis thaliana and other plants unveiled activation of shared molecular defense mechanisms between under individual and combined stresses. These shared plant responses are characterized by commonly regulated genes under individual and combined stresses. Based on the previous studies, G-box binding factor 3 (GBF3) is one of the regulatory components of such shared responses. However, the mechanistic understanding on the role of GBF3 under combined drought and pathogen stress is not yet decoded. Using genetic approaches, we demonstrated Atgbf3 mutant plants are more susceptible under individual and combined drought and Pseudomonas syringae pv. tomato DC3000 stresses as compared to the wild-type plants. We further analyzed the global transcriptome of Atgbf3 mutant under combined stress to identify its downstream targets to further validate the role of AtGBF3 in combined stress. We used microarrays to detail the global transcriptome reprogramming during AtGBF3-mediated regulation of combined stress.
Project description:With frequent fluctuations in global climate, plants often experience co-occurring dry-wet cycles and pathogen infection and this combination adversely affects plant survival. In the past, some studies indicated that morpho-physiological responses of plants to the combined stress are different from the individual stressed plants. However, interaction of drought stressed or drought recovered plants with pathogen has not been widely studied at molecular level. Such studies are important to understand the defense pathways that operate as part of combined stress tolerance mechanism. In this study, Arabidopsis plants were exposed to individual drought stress (soil drying at 40% FC, D), Pseudomonas syringae pv tomato DC3000 (PStDC3000), infection and their combination. Plants recovered from drought stress were also exposed to PStDC3000. Beside we have also infiltrated P. syringae pv tabaci (PSta, non-host pathogen) individually or in combination with drought stress. Using Affymetrix WT gene 1.0 ST array, global transcriptome profiling of plants leaves under individual drought stress and pathogen infection was compared with their combination. Results implicate that plants exposed to combined drought and pathogen stress experience a new state of stress where each combination of stressor and their timing defines the plant responses and thus should be studied explicitly. Global transcriptional analysis in Arabidopsis leaves exposed to individual and combined drought and pathogen stress.
Project description:Chickpea (Cicer arietinum) is the third largest legume grown worldwide and are prone to drought and various pathogen infections. These stresses often occur concurrently in the field conditions. Previous studies in other plant species indicated that plant senses concurrently occurring stresses as new state of stress however, the molecular events in response to that is largely unknown. In the present study, we studied the transcriptome changes in chickpea plants exposed to combination of drought stress and a potential wilt pathogen, Ralstonia solanacearum by microarray analysis. Chickpea plants were exposed to short duration individual drought (SD-drought, soil field capacity, FC-35%), long duration individual drought (LD-drought, FC-30%), short duration individual pathogen stress (SD-pathogen = 2 days pathogen infection), long duration individual pathogen stress (LD-pathogen = 4 days of infection) and short duration and long duration combined stress, SD-combined = 2 days of pathogen infection with progressive drought (FC-40% to FC- 35%), LD combined = 4 days of pathogen infection with progressive drought (FC-35% to 30%).Transcriptome analysis for the leaf samples from above treatment were done by microarray analysis using Agilent ChickpeaGXP_8X60K chip. Result indicated presence of specific molecular events and also some common but tailored events in response to combined stress. Global transcriptional analysis in chickpea leaves exposed to individual and combined drought stress and Ralstonia solanacearum infection.
Project description:Considering global climate changes, incidences of combined drought and heat stress are likely to increase in the future and will considerably influence plant-pathogen interactions. Until now, little is known about plants exposed to simultaneously occurring abiotic and biotic stresses. To shed some light on molecular plant responses to multiple stress factors, a versatile multi-factorial test system, allowing simultaneous application of heat, drought and virus stress, was developed. Comparative analysis of single, double and triple stress responses by transcriptome and metabolome analysis revealed that gene expression under multi-factorial stress is not predictable from single stress treatments. Hierarchical cluster and principal component analysis identified heat as the major stress factor clearly separating heat-stressed from non-heat stressed plants. We identified 11 genes differentially regulated in all stress combinations as well as 23 genes specifically-regulated under triple stress. Furthermore, we showed that virus treated plants displayed enhanced expression of defense genes, which was abolished in plants additionally subjected to heat and drought stress. Triple stress also reduced expression of genes involved in the R-mediated disease response and increased the cytoplasmic protein response which was not seen under single stress conditions. These observations suggested that abiotic stress factors significantly altered TuMV-specific signaling networks which lead to a deactivation of defense responses and a higher susceptibility of plants. Collectively, our transcriptome and metabolome data provide a powerful resource to study plant responses during multi-factorial stress and allows identifying metabolic processes and functional networks involved in tripartite interactions of plants with their environment. Stress induced gene expression in Arabidopsis leaves was measured after exposure to single and combined abiotic and biotic stress. Plants were grown on soil for 21 days till virus infection. Eight days later controlled drought stress was applied. At the end of the treatments heat was applied for three days. Four biological replicates have been hybridized for each treatment. Furthermore, Arabidopsis plants were exposed to a single severe heat stress (37°C day/33°C night) to mimic the severity of the triple stress experiment.
Project description:Considering global climate changes, incidences of combined drought and heat stress are likely to increase in the future and will considerably influence plant-pathogen interactions. Until now, little is known about plants exposed to simultaneously occurring abiotic and biotic stresses. To shed some light on molecular plant responses to multiple stress factors, a versatile multi-factorial test system, allowing simultaneous application of heat, drought and virus stress, was developed. Comparative analysis of single, double and triple stress responses by transcriptome and metabolome analysis revealed that gene expression under multi-factorial stress is not predictable from single stress treatments. Hierarchical cluster and principal component analysis identified heat as the major stress factor clearly separating heat-stressed from non-heat stressed plants. We identified 11 genes differentially regulated in all stress combinations as well as 23 genes specifically-regulated under triple stress. Furthermore, we showed that virus treated plants displayed enhanced expression of defense genes, which was abolished in plants additionally subjected to heat and drought stress. Triple stress also reduced expression of genes involved in the R-mediated disease response and increased the cytoplasmic protein response which was not seen under single stress conditions. These observations suggested that abiotic stress factors significantly altered TuMV-specific signaling networks which lead to a deactivation of defense responses and a higher susceptibility of plants. Collectively, our transcriptome and metabolome data provide a powerful resource to study plant responses during multi-factorial stress and allows identifying metabolic processes and functional networks involved in tripartite interactions of plants with their environment. Stress induced gene expression in Arabidopsis leaves was measured after exposure to single and combined abiotic and biotic stress. Plants were grown on soil for 21 days till virus infection. Eight days later controlled drought stress was applied. At the end of the treatments heat was applied for three days. In parallel, a homozougus T-DNA insertion line SALK_021115C (N672283), located in the Arabidopsis gene At5g45000 has been exposed to the same stress conditions. Four biological replicates have been hybridized for each treatment.
Project description:Biotic and abiotic stresses limit agricultural yields, and plants are often simultaneously exposed to multiple stresses. Combinations of stresses such as heat and drought or cold and high light intensity, have profound effects on crop performance and yeilds To analyze such responses, we initially compared transcriptome changes in ten Arabidopsis thaliana ecotypes using cold, heat, high light, salt and flagellin treatments as single stress factors or their double combinations.
Project description:Drought stress imposes severe challenges on agriculture by impacting crop performance. Understanding drought responses in plants at a cellular level is a crucial first step towards engineering improved drought resilience. However, the molecular responses to drought are complex as they depend on multiple factors including the severity of drought, the profiled organ, its developmental stage or even the cell types therein. Thus, deciphering the transcriptional responses to drought is specially challenging. In this study, we investigated tissue-specific responses to mild drought in young Arabidopsis thaliana (Arabidopsis) leaves using single-cell RNA sequencing (scRNA-seq). To preserve transcriptional integrity during cell isolation, we inhibited RNA synthesis using the transcription inhibitor actinomycin D, demonstrating the benefits of transcriptome fixation for studying mild stress responses at single-cell level. We present a curated and validated single-cell atlas comprising 50,797 high-quality cells from almost all known cell types present in the leaf. All cell types were validated with a new library of reporter lines.
Project description:The aim of this experiment is to understand the impact of overexpression of ERD15 on the transcriptome of Arabidopsis thaliana. ERD15 was isolated from a screen for genes rapidly induced after pathogen treatment from Arabidopsis. This gene was originally found as early responsive to drought (Kiyosue et al., 1994, Plant Physiol 106, 1707). ABA is central phytohormone in drought response, but increasing information is pointing to its significant role in pathogen responses as well. We are interested to see the effect of this hormone on plants overexpressing ERD15 compared to control plants. The samples (rosette leaves)will be harvested from 3-week old soil grown plants 90 min after spraying with 100 micromolar ABA. Comparison will be made with non-treated plant samples. Experimenter name = Elina Helenius Experimenter phone = +358 9 191 59085 Experimenter fax = +358 9 191 59079 Experimenter institute = University of Helsinki Experimenter address = Viikinkaari 5 D Experimenter address = P.O.Box 56 Experimenter address = Helsinki Experimenter zip/postal_code = 00014 Experimenter country = Finland Keywords: compound_treatment_design
Project description:The leaf transcriptome of the Arabidopsis thaliana aquaporin gene PIP1;2 T-DNA insertion line was compared to that of control plants. In total 730 genes were found to be differentially regulated. This regulation pattern was compared to mild drought stress and low CO2 Affymetrix data to elucidate whether loss of the aquaporin resembles transcriptomic changes of drought stress or lack of CO2 supply. Mild drought stress data were obtained from Harb A, Krishnan A, Ambavaram MMR, Pereira A (2010) Molecular and Physiological Analysis of Drought Stress in Arabidopsis Reveals Early Responses Leading to Acclimation in Plant Growth. Plant Physiology 154: 1254-1271 (GSE24177). Low CO2 data were obtained from Oliver E. Bläsing, Yves Gibon, Manuela Günther, Melanie Höhne, Rosa Morcuende, Daniel Osuna, Oliver Thimm, Björn Usadel, Wolf-Rüdiger Scheible, and Mark Stitt (2005) Sugars and Circadian Regulation Make Major Contributions to the Global Regulation of Diurnal Gene Expression in Arabidopsis. The Plant Cell, Vol. 17, 3257-3281 (GSE3423).
Project description:Considering global climate changes, incidences of combined drought and heat stress are likely to increase in the future and will considerably influence plant-pathogen interactions. Until now, little is known about plants exposed to simultaneously occurring abiotic and biotic stresses. To shed some light on molecular plant responses to multiple stress factors, a versatile multi-factorial test system, allowing simultaneous application of heat, drought and virus stress, was developed. Comparative analysis of single, double and triple stress responses by transcriptome and metabolome analysis revealed that gene expression under multi-factorial stress is not predictable from single stress treatments. Hierarchical cluster and principal component analysis identified heat as the major stress factor clearly separating heat-stressed from non-heat stressed plants. We identified 11 genes differentially regulated in all stress combinations as well as 23 genes specifically-regulated under triple stress. Furthermore, we showed that virus treated plants displayed enhanced expression of defense genes, which was abolished in plants additionally subjected to heat and drought stress. Triple stress also reduced expression of genes involved in the R-mediated disease response and increased the cytoplasmic protein response which was not seen under single stress conditions. These observations suggested that abiotic stress factors significantly altered TuMV-specific signaling networks which lead to a deactivation of defense responses and a higher susceptibility of plants. Collectively, our transcriptome and metabolome data provide a powerful resource to study plant responses during multi-factorial stress and allows identifying metabolic processes and functional networks involved in tripartite interactions of plants with their environment. Stress induced gene expression in Arabidopsis leaves was measured after exposure to single and combined abiotic and biotic stress. Plants were grown on soil for 21 days till virus infection. Eight days later controlled drought stress was applied. At the end of the treatments heat was applied for three days. Four biological replicates have been hybridized for each treatment.