Gene expression patterns in roots of Camelina sativa with enhanced salinity tolerance arising from growth in soil treated with plant growth promoting bacteria producing ACC deaminase or from expression of the corresponding acdS gene in transgenic lines
ABSTRACT: Gene expression patterns in roots of Camelina sativa with enhanced salinity tolerance arising from growth in soil treated with plant growth promoting bacteria producing 1-aminocyclopropane-1-carboxylate deaminase (ACC deaminase) or from expression of the corresponding acdS gene in transgenic lines. Salinity stress negatively affects crop production. However in camelina, grown in soils treated with PGPB producing 1-aminocyclopropane-1-carboxylate deaminase (acdS ) or transgenic lines expressing acdS exhibited increased salinity tolerance. AcdS reducing the level of stress ethylene to below the point where it is inhibitory to growth. Gene expression patterns in roots responding to salt stress was affected by the expression of acdS under the control of CaMV 35S or root-specific (rolD) promoters in transgenic lines, or by growth in soils treated with endophytic PGPB producing acdS indicate that the number of the genes were differentially expressed were more assigned to genome III in transgenic plants however in PGPB treated plants the number of the genes were differentially expressed were almost equally assigned to all three genomes. Different promoter may induce different set or even different homeologues genes in camelina with probably the same function in response to salt stress. Though root is not a photosynthetic tissue reduction of the ethylene in root cells has positive effect on plant photosynthetic machinery. The expression of the genes involved in minor CHO metabolism was up-regulated mainly in roots of acdS contain plants during salt stress. Moderate reduction in ethylene production has positive effect on root growth during salt stress but reduction of the ethylene higher than a certain level has negative effect on root growth due to reduction of the expression of the genes involved in root cell elongation. AcdS gene modulating the level of ROS in cells in the level that induce ROS signaling but preventing cellular damage by make a balance on up and down-regulation of the genes involved in oxidation-reduction process in root cells under salinity stress. The acdS containing PGPB (8R6) were mostly effected the ethylene signaling and ABA biosynthesis and signaling in positive way but transgenic line depends to the promoter affecting Auxin, JA and BR signaling or biosynthesis. Overall design: Four experimental conditions were tested: the parental Camelina (DH55), a transgenic with acdS contitutively expressed (35S::acdS), a transgenic with acdS most highly expressed in roots (rolD::acdS), and DH55 exposed to a plant growth promoting bacteria expressing acdS (8R6). Camelina roots (DH55, 35S::acdS, rolD::acdS, PGPB (8R6)) with salt treatment were analyzed. 3 replicates of each were compared.
Project description:The purpose of this experiment was to study the effects of a bacterial ACC deaminase transgene in the roots and its impact on nickel tolerance of canola. ACC deaminase breaks down 1-aminocyclopropane-1-carboxylic acid, the biosynthetic precursor to the plant hormone ethylene, lowering ethylene levels and improving plant tolerance to stress. Ethylene evolved during plant stress is thought to causes senescence and cell death and worsen stress symptoms. Transgenic plants expressing ACC deaminase from the plant growth-promoting bacteria Pseudomonas putida UW4 are more tolerant to heavy metals in the soil and this expression study helps to illuminate the pathways responsible for this tolerance.
Project description:The purpose of this experiment was to study the effects of the bacterial enzyme ACC deaminase on the transcriptional changes within canola seedlings. Seedlings from seeds treated with the plant growth-promoting bacteria Pseudomonas putida UW4 which expresses a high level of ACC deaminase and its ACC deaminase-minus mutant were compared to untreated seedlings along with a transgenic line of canola expressing the ACC deaminase enzyme in the roots. ACC deaminase breaks down 1-aminocyclopropane-1-carboxylic acid, the biosynthetic precursor to the plant hormone ethylene, lowering ethylene levels and improving plant fitness. Plants treated with the ACC deaminase-containing bacteria and transgenic plants expressing ACC deaminase are more tolerant to a variet of stresses and this expression study helps to illuminate the pathways responsible for the growth promotion provided by the beneficial bacteria and the role of the enzyme itself.
Project description:Soil salinity presents a notable challenge to agriculture and to increasing the use marginal lands for farming. Here we provide a detailed analysis of the physiology, chemistry and gene expression patterns in roots and shoots of Camelina sativa in response to salt stress. Salt treatment reduced shoot, but not root length. Root and shoot weight were affected by salt, as was photosynthetic capacity. Salt treatment did not alter micro-element concentration in shoots, but increased macro-element (Ca and Mg) levels. Gene expression patterns in shoots indicated that salt stress may have led to shuttling of Na+ from the cytoplasm to the tonoplast and to an increase in K+ and Ca+2 import into the cytoplasm. In roots, gene expression patterns indicated that Na+ was exported from the cytoplasm by the SOS pathway and that K+ was imported in response to salt. Genes encoding proteins involved in chelation and storage were highly up-regulated in shoots, while metal detoxification appeared to involve various export mechanisms in roots. In shoots, genes involved in secondary metabolism leading to lignin, anthocyanin and wax production were up-regulated, probably to improve desiccation tolerance. Partial genome expression partitioning was observed in roots and shoots based on the expression of homeologous genes from the three C. sativa genomes. Genome I and II were involved in the response to salinity stress to about the same degree, while about 10 % more differentially-expressed genes were associated with Genome III. This study has provided valuable information and insight into the response of camelina to salt stress. Examination of this data and comparison to similar studies in more halophytic species will allow development of even more salt-tolerant varieties of this emerging industrial crop. Overall design: Camelina roots and shoots, with or without salt treatment, were analyzed. 3 replicates of each (root after salt treatment, root without salt treatment, shoot after salt treatment, shoot without salt treatment) were compared.
Project description:We found that primary root (PR) is more resistant to salt stress compared with crown roots (CR) and seminal roots (SR). To understand better salt stress responses in maize roots, six RNA libraries were generated and sequenced from primary root (PR), primary roots under salt stress (PR-salt) , seminal roots (SR), seminal roots under salt stress (SR-salt), crown roots (CR), and crown roots under salt stress (CR-salt). Through integrative analysis, we identified 444 genes regulated by salt stress in maize roots, and found that the expression patterns of some genes and enzymes involved in important pathway under salt stress, such as reactive oxygen species scavenging, plant hormone signal perception and transduction, and compatible solutes synthesis differed dramatically in different maize roots. 16 of differentially expressed genes were selected for further validation with quantitative real time RT-PCR (qRT-PCR).We demonstrate that the expression patterns of differentially expressed genes are highly diversified in different maize roots. The differentially expressed genes are correlated with the differential growth responses to salt stress in maize roots. Our studies provide deeper insight into the molecular mechanisms about the differential growth responses of different root types in response to environmental stimuli in planta. Examination of three root types of maize under salt treatment for understanding the different responding mechenism to salt stress.
Project description:With the growing limitations on arable land, alfalfa (a widely cultivated, low-input forage) is now being selected to extend cultivation into saline lands for low-cost biofeedstock purposes. Here, minerals and transcriptome profiles were compared between two new salinity-tolerant North American alfalfa breeding populations and a more salinity-sensitive Western Canadian alfalfa population grown under hydroponic saline conditions. All three populations accumulated two-fold higher sodium in roots than shoots as a function of increased electrical conductivity. At least 50% of differentially expressed genes (p < 0.05) were down-regulated in the salt-sensitive population growing under high salinity, while remaining unchanged in the saline-tolerant populations. In particular, most reduction in transcript levels in the salt-sensitive population were observed in genes specifying cell wall structural components, lipids, secondary metabolism, auxin and ethylene hormones, development, transport, signalling, heat shock, proteolysis, pathogenesis-response, abiotic stress, RNA processing, and protein metabolism. Transcript diversity for transcription factors, protein modification, and protein degradation genes was also more strongly affected in salt-tolerant CW064027 than in salt-tolerant Bridgeview and salt-sensitive Rangelander, while both saline-tolerant populations showed more substantial up-regulation in redox-related genes and B-ZIP transcripts. The report highlights the first use of bulked genotypes as replicated samples to compare the transcriptomes of obligate out-cross breeding populations in alfalfa. Three lines of Alfalfa (salt-tolerant CW064027, salt-tolerant Bridgeview, salt-sensitive Rangelander) were grown on 3 different concentrations of salt. For each cultivar-salt condition, 3 biological replicates were collected for a total of 27 samples.
Project description:We report that CBP20 phosphorylation can regulate root growth in ethylene. We examined the gene expression in roots and shoots of wild type (Col) and cbp20 mutant (in Col background). Ethylene is one of the most essential hormones for plant developmental processes and stress responses. EIN2 is a key factor in ethylene signaling pathway and its function is regulated by phosphorylation. However, the phosphorylation regulation in the ethylene signaling pathway is largely unknown. Here we report the phosphorylation of CBP20 is regulated by ethylene, and the phosphorylation is involved in root elongation. The constitutive phosphorylation format of CBP20 rescues the cbp20 root ethylene hyposensitive phenotype, while the constitutive de-phosphorylation format of CBP20 is unable to rescue the root phenotype of cbp20 in response to ethylene. Genome wide study on ethylene regulated gene expression and microRNA expression in the roots and shoots of both Col and cbp20, together with the result of genetics validation suggest that ethylene induced phosphorylation of CBP20 is involved in root growth and one pathway is through the regulation of microRNAs and their target genes in roots. Overall design: Root and shoot mRNA profiles of 3-day old wild type (Col) and cbp20 mutant (in Col background) were generated by sequencing, in 2 replications, using Illumina HiSeq 4000
Project description:We report that CBP20 phosphorylation can regulate root growth in ethylene. We examined the small RNA expression in roots and shoots of wild type (Col) and cbp20 mutant (in Col background). Ethylene is one of the most essential hormones for plant developmental processes and stress responses. EIN2 is a key factor in ethylene signaling pathway and its function is regulated by phosphorylation. However, the phosphorylation regulation in the ethylene signaling pathway is largely unknown. Here we report the phosphorylation of CBP20 is regulated by ethylene, and the phosphorylation is involved in root elongation. The constitutive phosphorylation format of CBP20 rescues the cbp20 root ethylene hyposensitive phenotype, while the constitutive de-phosphorylation format of CBP20 is unable to rescue the root phenotype of cbp20 in response to ethylene. Genome wide study on ethylene regulated gene expression and microRNA expression in the roots and shoots of both Col and cbp20, together with the result of genetics validation suggest that ethylene induced phosphorylation of CBP20 is involved in root growth and one pathway is through the regulation of microRNAs and their target genes in roots. Overall design: Root and shoot small RNA profiles of 3-day old wild type (Col) and cbp20 mutant (in Col background) were generated by sequencing, in 2 replications, using Illumina HiSeq 4000
Project description:Abiotic stresses such as salinity are very important factors limiting rice growth and productivity around the world. Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the gene expression pattern of rice responsive to salinity stress, try to elucidate the difference of genome-wide gene expression profiling of two contrasting rice genotypes in response to salt stress and to discover the salinity related genes and gene interaction and networks. Under salinity condition, the number of differentially expressed genes (DEGs) in 177-103 was more than that in IR64, and most of up-regulated DEGs in 177-103 are response to stress. But in IR64, most of up-regulated DEGs are transcription related genes. The DEGs under salinity showed very strong tissue specificity, the number of DEGs in leaf was more than that in root. A lot of genes differentially expressed by exogenous ABA treatment under salinity condition, such as Leaf senescence protein, 1-deoxy-D-xylulose 5-phosphate synthase 2 precursor and Protein of unknown function DUF26 were induced by ABA and contributed to salinity tolerance. In this study, the gene expression patterns across two organs including leaves and roots at seedling stage were characterized under control, salinity, salinity+ABA treatments by using the Affymetrix rice microarray platform based on a salinity tolerant rice line derived from IR64.
Project description:Analysis of root gene expression of salt-tolerant genotypes FL478, Pokkali and IR63731, and salt-sensitive genotype IR29 under control and salinity-stressed conditions during vegetative growth. Results provide insight into the genetic basis of salt tolerance in indica rice. Keywords: stress response Overall design: Seedlings were cultured in sand and irrigated with a nutrient solution for 22 d (salt-treated) and 30 d (control) after germination, respectively. Salinity treatment was applied by adding NaCl and CaCl2 (5:1 molar concentration) in two steps over a period of 3 days (final electrical conductivity: 7.4 dS m-1) to prevent osmotic shock. All plants were harvested on day 30.
Project description:One of the primary objectives of plant biotechnology is to increase resistance to abiotic stresses, such as salinity. Salinity is a major abiotic stress and increasing crop resistant to salt continues to the present day as a major challenge. Salt stress disturbs cellular environment leading to protein misfolding, affecting normal plant growth and causing agricultural losses worldwide. The advent of state-of-the-art technologies such as high throughput mRNA sequencing (RNA-Seq) has revolutionized whole-transcriptome analysis by allowing, with high precision, to measure changes in gene expression. In this work, we used tissue-specific RNA-Seq to gain insight into the Petunia hybrida transcriptional responses under sodium chloride (NaCl) stress using a controlled hydroponic system. Roots and leaves samples were taken from a continuum of 48 hours of acute 150 mM NaCl. This analysis revealed a set of tissue- and- time point specific differentially expressed genes, such as genes related to transport, signal transduction, ion homeostasis as well as novel and undescribed genes, such as Peaxi162Scf00003g04130 and Peaxi162Scf00589g00323 expressed only in roots under salt stress. In this work, we identified early and late expressed genes in response to salt stress while providing a core of differentially express genes across all time points and tissues, including the trehalose-6-phosphate synthase 1 (TPS1), a glycosyltransferase reported in salt tolerance in other species. To test the function of the novel petunia TPS1 allele, we cloned and showed that TPS1 is a functional plant gene capable of complementing the trehalose biosynthesis pathway in mutants (tps1) yeast. The list of candidate genes to enhance salt tolerance provided in this work constitutes a major effort to better understand the detrimental effects of salinity in petunia with direct implications for other economically important Solanaceous species Overall design: Assessing the petunia response to salt stress