Project description:In this study a transcriptomic approach (RNA-sequencing) was utilized to elucidate molecular responses of maize (Zea mays L.) primary roots of the inbred line B73 to water deficit to gain a better understanding of the mechanisms underlying drought tolerance. Kernels of the maize inbred line B73 were germinated in paper rolls soaked with distilled water until seedlings had a primary root length of 2 to 4 cm. For mild and severe water deficit conditions, seedlings were transferred to PEG8000 solution with water potentials of -0.2 MPa and -0.8 MPa, respectively. Water deficit treatment was applied for 6 h and 24 h. Each treatment was performed in four biological replicates each consisting of 10 roots.
Project description:In this study RNA-sequencing was used to monitor gene expression changes in four tissues (meristematic zone, elongation zone, and cortex and stele of the mature zone) of maize (Zea mays L.) primary roots in response to water deficit to gain a better understanding of the mechanisms underlying drought tolerance.
Project description:Maize transgenic event MON810, grown and commercialised worldwide, is the only cultivated GM event in EU. Maize MON810, variety DKC6575, and the corresponding near-isogenic Tietar were studied in different growing conditions, to assess their behaviour in response to drought. Profiling gene expression in water deficit regimes and in generalised water stress showed an up-regulation of different stress- responsive genes. A greater number of differentially expressed genes was observed in Tietar rather than in DKC6575, with genes belonging to transcription factor families and genes encoding HSPs, LEAs and detoxification enzymes. Since these genes have been from literature, indicated as typical of stress responses, their activation in Tietar rather than in DKC6575 may be reminiscent of a more efficient water stress response. DKC6575 was also analysed for the expression of the transgene CryIAb (encoding for the delta-endotoxin insecticidal protein) in water limiting conditions. In all the experiments the CryIAb transcript was not influenced by water stress, but expressed at a constant level. This suggests that though a different pattern of sensitivity to stress, the transgenic variety maintains the same expression level for the transgene. The Maize Oligonucleotide microarray was used to measure differences in gene expression levels under drought stress in DKC6575 and in the near-isogenic variety Tietar growing in the field. The gene expression profile of each variety was evaluated at T1 and at T2 for samples fully irrigated and at T2 for samples with irrigation deficit.
Project description:Maize transgenic event MON810, grown and commercialised worldwide, is the only cultivated GM event in EU. Maize MON810, variety DKC6575, and the corresponding near-isogenic Tietar were studied in different growing conditions, to assess their behaviour in response to drought. Profiling gene expression in water deficit regimes and in generalised water stress showed an up-regulation of different stress- responsive genes. A greater number of differentially expressed genes was observed in Tietar rather than in DKC6575, with genes belonging to transcription factor families and genes encoding HSPs, LEAs and detoxification enzymes. Since these genes have been from literature, indicated as typical of stress responses, their activation in Tietar rather than in DKC6575 may be reminiscent of a more efficient water stress response. DKC6575 was also analysed for the expression of the transgene CryIAb (encoding for the delta-endotoxin insecticidal protein) in water limiting conditions. In all the experiments the CryIAb transcript was not influenced by water stress, but expressed at a constant level. This suggests that though a different pattern of sensitivity to stress, the transgenic variety maintains the same expression level for the transgene.
Project description:Transcriptome sequencing (RNA-seq) was used to profile genome-wide transcript abundance in the primary root growth zone (PRGZ) of maize seedlings grown in different water deficit treatments: well-watered (-0.02 MPa), mild water deficit stress (-0.3 MPa), or severe water deficit stress (-1.6 MPa). For each water deficit treatment, the PRGZ transcriptome was profiled at 26 hours after initiation of the water deficit treatment. By comparing the abundance of each transcript under mild or severe water deficit stress relative to its abundance under well-watered conditions, we identified transcripts that are differentially regulated in the PRGZ in response to the two levels of water deficit stress.
Project description:Periods of soil water deficit could occur at any time during the crop season, but maize is particularly sensitive to water stress around flowering time. At this time the stress usually causes remarkable yield loss. Heading time, which is just before tassel flowering, is one of the most important stages that maize productivity would be affected severely if plants encounter water stress. The whole-genomic gene expression changes of maize plants in response to water deficit stress at this stage have not been studied. The present work utilized an Arizona Maize Oligonucleotide Array Version 1.9,which was consisted of A and B slides carrying with a total of 57,452 maize 70-mer oligonucleotides, was used to monitor gene expression profile changes in maize leaves subjected to 1 day and 7 days water-deficit stress respectively at the heading stage. Keywords: stress response
Project description:A customized targeted oligoarray was used to monitor the expression levels of 1000 genes, representative of the immature kernel transcriptome. Using this oligoarray we compared transcripts from 10 DAP kernels of two susceptible and two drought tolerant genotypes. These four genotypes were extracted from our RIL population (B73xH99) and grown under water stress and well watered field conditions. Keywords: Stress response
Project description:Arabidopsis thaliana plants that have experienced an initial exposure to dehydration stress (“trained plants”) have an increased ability to maintain leaf relative water content (RWC) during subsequent stresses than plants experiencing the stress for the first time and transcription of selected dehydration response genes is altered during successive exposures to dehydration stress. This physiological and transcriptional behavior of trained plants is consistent with a “memory “of an earlier stress. It is unknown whether such memory is present in other Angiosperm lineages and whether it is an evolutionarily conserved response to stress (see E-GEOD-48235). Here, we analyzed the behavior and transcriptomes of maize (Zea mays) plants experiencing multiple dehydration stresses and compare them with responses of the evolutionarily distant A. thaliana. We found structurally related genes in maize that displayed the same memory-type responses as in A. thaliana, providing evidence of the conservation of function and transcriptional memory in the evolution of plants’ dehydration stress response systems. Similar to A. thaliana, trained Z. mays plants retained higher RWC during dehydration stress than untrained plants, due in part to maintaining reduced stomatal conductance, despite full recovery of RWC, after the first stress. Divergent transcriptional memory responses were also expressed, suggesting diversification of function among stress memory genes. Some dehydration stress memory genes were also shared with other stress and hormone responding pathways, indicating complex and dynamic interactions between different plant signaling networks. The results provide new insight into how plants respond to multiple dehydration stresses and provide a platform for studies of the functions of memory genes in adaptive responses to water deficit in monocot and eudicot plants . For each condition (water, S1, and S3) the transcriptome was sequenced for two replicates. The watered condition is considered the control.
Project description:Arabidopsis thaliana plants that have experienced an initial exposure to dehydration stress (“trained plants”) have an increased ability to maintain leaf relative water content (RWC) during subsequent stresses than plants experiencing the stress for the first time and transcription of selected dehydration response genes is altered during successive exposures to dehydration stress. This physiological and transcriptional behavior of trained plants is consistent with a “memory “of an earlier stress. It is unknown whether such memory is present in other Angiosperm lineages and whether it is an evolutionarily conserved response to stress. Here, we analyzed the behavior and transcriptomes of maize (Zea mays) plants experiencing multiple dehydration stresses and compare them with responses of the evolutionarily distant A. thaliana. We found structurally related genes in maize that displayed the same memory-type responses as in A. thaliana, providing evidence of the conservation of function and transcriptional memory in the evolution of plants’ dehydration stress response systems. Similar to A. thaliana, trained Z. mays plants retained higher RWC during dehydration stress than untrained plants, due in part to maintaining reduced stomatal conductance, despite full recovery of RWC, after the first stress. Divergent transcriptional memory responses were also expressed, suggesting diversification of function among stress memory genes. Some dehydration stress memory genes were also shared with other stress and hormone responding pathways, indicating complex and dynamic interactions between different plant signaling networks. The results provide new insight into how plants respond to multiple dehydration stresses and provide a platform for studies of the functions of memory genes in adaptive responses to water deficit in monocot and eudicot plants .