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. Four biological replicates have been hybridized for each treatment.
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:Rice is the major staple food for more than half of world's population. As global climate changes, we are observing more floods, droughts and severe heat waves. Two rice cultivars with contrasting genetic backgrounds and levels of tolerance to drought, Nipponbare and IAC1131, were used in this study. Four-week-old seedlings of both cultivars were grown in large soil volumes and then exposed to moderate and extreme drought for 7 days, followed by 3 days of re-watering. Mature leaves were harvested from plants from each treatment for protein extraction and subsequent shotgun proteomic analysis, with validation of selected proteins by western blotting. Gene Ontology (GO) annotations of differentially expressed proteins provide insights into the metabolic pathways that are involved in drought stress resistance. Our data indicate that IAC1131 appears to be better able to cope with stressful conditions by up regulating a suite of stress and defence response related proteins. Nipponbare, in contrast, lacks the range of stress responses shown by the more stress tolerant variety, and responds to drought stress by initiating a partial shutdown of chlorophyll biosynthesis in an apparent attempt to preserve resources.
Project description:Rice is the major staple food for more than half of world's population. As global climate changes, we are observing more floods, droughts and severe heat waves. Two rice cultivars with contrasting genetic backgrounds and levels of tolerance to drought, Nipponbare and IAC1131, were used in this study. Four-week-old seedlings of both cultivars were grown in large soil volumes and then exposed to moderate and extreme drought for 7 days, followed by 3 days of re-watering. Mature leaves were harvested from plants from each treatment for protein extraction and subsequent shotgun proteomic analysis, with validation of selected proteins by western blotting. Gene Ontology (GO) annotations of differentially expressed proteins provide insights into the metabolic pathways that are involved in drought stress resistance. Our data indicate that IAC1131 appears to be better able to cope with stressful conditions by up regulating a suite of stress and defence response related proteins. Nipponbare, in contrast, lacks the range of stress responses shown by the more stress tolerant variety, and responds to drought stress by initiating a partial shutdown of chlorophyll biosynthesis in an apparent attempt to preserve resources.
Project description:The severity of impact of drought on crops is contingent on the developmental stage of the plant, with the most sensitive stage being the reproductive stage. Hence, gene expression profiling has been used to understanding drought response and resistance mechanism in rice. Here we present drought transcriptomes of rice in three developmental stages and gain insights into the processes and regulatory mechanisms involved in common and stage specific drought responses. Total RNA was isolated from the rice seedlings, vegetative (V4) and reproductive (R4) tissues of both control and stress treated plants for hybridization on Affymetrix microarrays. Two independent replicates for seedling and reproductive stages, and three replicates for vegetative stages were generated, for both control and stress samples. For drought treatments, plants were gradually subjected to field drought conditions in order to reach 50% field capacity (FC) by regulating water supply, whereas control plants were maintained at 100% FC.
Project description:We use the gowth zone of the maize leaf as a model system to study the growth reduction in response to drought stress. The spatial gradient and the relatively large size of the maize leaf allowed us to sample at a subzonal rezolution and to examine different developmental stages at the same time. We compared the response to different levels of drought stress (mild and severe) of proliferating (meristem), expanding (elongation zone) and differentiated (mature zone) tissue. Three separate loop designs were used for the three zones of the maize leaf (meristem, elongation zone, and mature zone). In each loop three treatments were contrasted (control, mild stress, and severe stress). Four biological replicates were used for each zone/condition (4 replicates x 3 zones x 3 conditions = 36 samples).
Project description:Plants require a distinctive cohort of enzymes to coordinate division and cell expansion. Proteomic analysis now enables interrogation of immature leaf bases where these processes occur. Hence we investigated proteins in tissues sampled from leaves of a drought-tolerant rice (IAC1131) to provide insights into the effect of soil drying on gene expression when compared with the drought-sensitive Nipponbare. Shoot growth zones were dissected to count dividing cells and extract protein for subsequent Tandem Mass Tags (TMT) quantitative proteomic analysis. Gene Ontology (GO) annotations of differentially expressed proteins provided insights into responses of Nipponbare and IAC1131 to drought. Soil drying did not affect the proportion of mitotic cells in IAC1131. More than 800 proteins across most functional categories were up-regulated in drought (and down-regulated on re-watering) in IAC1131, including those involved in organization of the meristem and subsequent cell formation. On the other hand, the proportion of dividing cells in Nipponbare was severely impaired during drought and fewer than 200 proteins responded in abundance when the growing zones underwent a drying cycle. However, those proteins involved in oxidation state and response to external stimuli were more likely to be upregulated by drought, even in Nipponbare.
Project description:This study was aimed at deciphering the impact of drought and heat on genome-wide gene expression in flag leaf of barley. We employed high-throughput sequencing of mRNA to identify genes that are associated with response to drought or heat and to their combination. Our study demonstrated that under combined stress, drought was the dominant factor affecting genes expression. It was also confirmed for phenotypic traits and chlorophyll fluorescence parameters. Drought- and heat-responsive genes were associated majorly with photosynthesis, abscisic acid signaling and lipids transport. Dehydrin encoding genes were found to be universal stress-responsive genes. Stress-induced genes specific to the flag leaf size were also found. This research provided novel insight into molecular mechanisms of barley flag leaf that determine drought and heat response, also during their co-occurrence.
Project description:Transcriptional profiling of rossette leaves comparing wild type (Col-0) and the mutant (hsi2-5) under no drought or simulated drought stress. Two-condition experiment; wild type (col-0) vs. mutant (hsi2-5). Three stages of drought; no drought (or stage 0), mild drought or soil drying but no visible wiliting (or stage 1), visible wilting (stage 2). At stage 0, four biological replicates of the wild type/mutant co-hybridized, at stage 1 and stage 2, three biological replicates of the wild type/mutant co-hybridized.