Project description:Background: Sorghum bicolor is a remarkably drought tolerant cereal crop. Its natural biodiversity that enables this tolerance has developed in sub-Saharan Africa. The sequencing of the sorghum genome in 2009 has expedited research of this crop which has also been proposed as a model C4 cereal crop for genomics. In this study, the genetic response mechanisms involved in sorghums’ tolerance to progressive water deficit and moderate re-watering were investigated in three previously uncharacterized South African landraces (designated: LR5, LR6 and LR35) using cDNA microarrays comprising 35 899 transcript probes. Results: Across the three landraces, significant differential expression of 1 797 genes, including 264 genes with currently unknown functions, were altered in response to progressive water stress and re-watering. The modulated sorghum genes had homology to proteins involved in growth, regulation, and protection. Gene ontology analysis identified significant enrichment of 26 genes involved in the ‘response to abiotic stimulus’ GO category in LR6 during severe stress. The expression of USP responded to progressive water stress and moderate re-watering in LR6 and LR35. Moreover, our results indicate a putative role for β-alanine betaine biosynthesis in drought tolerance of sorghum. Conclusions: This study identified the drought responsive gene complement of three previously uncharacterized South African sorghum landraces. Each landrace is a distinct genotype and similar responses to water deficit and re-watering were not expected. Functional characterizations of some of the differentially expressed genes found in this study may be used as possible targets for marker-assisted breeding or transgenic initiatives for sorghum and, other closely related crop species.
Project description:Sorghum is an important crop often subjected to simultaneous high temperatures and drought in the field. We examined the gene expression response to heat and drought stress both individually, and in combination, with the aim of identifying important stress tolerance mechanisms.
Project description:Sorghum is an important crop often subjected to simultaneous high temperatures and drought in the field. We examined the gene expression response to heat and drought stress both individually, and in combination, with the aim of identifying important stress tolerance mechanisms. Plants were subjected to 4 different conditions (control, heat shock, drought stress and combined heat and drought stress). 3 replicates were carried out for each treatment type giving a total of 12 samples
Project description:Common bean (Phaseolus vulgaris L.) is a relevant crop cultivated over the world, largely in water insufficiency vulnerable areas. Since drought is the main environmental factor restraining worldwide crop production, efforts have been invested to amend drought tolerance in commercial common bean varieties. However, scarce molecular data are available for those cultivars of P. vulgaris with drought tolerance attributes. As a first approach, Pinto Saltillo (PS), Azufrado Higuera (AH), and Negro Jamapa Plus (NP) were assessed phenotypically and physiologically to determine the outcome in response to drought on these common bean cultivars. Based on this, a Next-generation sequencing approach was applied to PS, which was the most drought-tolerant cultivar to determine the molecular changes at the transcriptional level. The RNA-Seq analysis revealed that numerous PS genes are dynamically modulated by drought. In brief, 1005 differentially expressed genes (DEGs) were identified, from which 645 genes were up-regulated by drought stress, whereas 360 genes were down-regulated. Further analysis showed that the enriched categories of the up-regulated genes in response to drought fit to processes related to carbohydrate metabolism (polysaccharide metabolic processes), particularly genes encoding proteins located within the cell periphery (cell wall dynamics). In the case of down-regulated genes, heat shock-responsive genes, mainly associated with protein folding, chloroplast, and oxidation-reduction processes were identified. Our findings suggest that secondary cell wall (SCW) properties contribute to P. vulgaris L. drought tolerance through alleviation or mitigation of drought-induced osmotic disturbances, making cultivars more adaptable to such stress. Altogether, the knowledge derived from this study is significant for a forthcoming understanding of the molecular mechanisms involved in drought tolerance on common bean, especially for drought-tolerant cultivars such as PS.
Project description:The present study is expected to reveal regulatory network of small RNAs under drought in Sorghum (Sorghum bicolor (L.) Moench). Sorghum genotype drought tolerant (DT) and drought susceptible (DS) were grown at 28-32 degrees C day/night temperature with 12/12 h light/dark period in the phytotron glass house. The fully opened uppermost leaves from control and drought stressed seedlings were sampled and stored at -80 degrees C, and used for generation of a small RNA library. Total RNA was isolated from the leaves using the TRIzol reagent (Invitrogen, USA). Small RNA sequencing libraries were prepared using Illumina Truseq small RNA Library preparation kit following manufacturer's protocol and these libraries were sequenced on GAIIx platform (Illumina Inc., USA). Small RNA reads contaminated with poor-quality and adaptor sequences were trimmed by using the UEA sRNA workbench 2.4- Plant version sequence file pre-processing (http://srna-tools.cmp.uea.ac.uk/). Then, all unique reads were submitted to the UEA sRNA toolkit-Plant version miRCat pipeline (http://srna-tools.cmp.uea.ac.uk/) to predict novel miRNAs from high-throughput small RNA sequencing data.
Project description:Rice (Oryza sativa), the major staple food crop is being cultivated under varying ecosystems ranging from irrigated lowland to rainfed upland environments. Improvement in the rice production under drought prone unfavourable environment depends on the development of drought tolerant genotypes which needs thorough understanding of physiological and molecular events behind the tolerance mechanism. There is considerable genetic variation for drought tolerance mechanism within the cultivated gene pool. To understand the diversity of drought response, two indica rice genotypes namely, i) Apo, an up-land drought tolerant indica veriety from Philippines and ii) IR64, a popular high yielding drought susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under control and drought stressed conditions during vegetative phase. Keywords: Drought response
Project description:This study used with RNA-Seq to examine the tissue specific expression data within sorghum plants for improving the Sorghum bicolor gene annotation. We examined the RNA from tissues (spikelet, seed and stem) in Sorghum bicolor (BTx623).Total RNAs form each tissues were extracted using SDS/phenol method followed by LiCl purification
Project description:Rice (Oryza sativa), the major staple food crop is being cultivated under varying ecosystems ranging from irrigated lowland to rainfed upland environments. Improvement in the rice production under drought prone unfavourable environment depends on the development of drought tolerant genotypes which needs thorough understanding of physiological and molecular events behind the tolerance mechanism. There is considerable genetic variation for drought tolerance mechanism within the cultivated gene pool. To understand the diversity of drought response, two indica rice genotypes namely, i) Apo, an up-land drought tolerant indica veriety from Philippines and ii) IR64, a popular high yielding drought susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under control and drought stressed conditions during vegetative phase. Keywords: Drought response We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during drought stress. We used two contrasting rice genotypes (IR64 drought susceptible and Apo drought tolerant) differing in their degree of drought tolerance. Plants were grown under green house conditions and drought stress was imposed on 33rd DAS. Leaf sampling was done in both control and drought stressed plants after 6 days of drought stress. Three replications of microarray experiments were carried out by hybridizing the control samples against the drought stressed samples.
Project description:We report transcriptome profiling of middle internode tissues from four development stages and three soil moisture readings representing progressive drought stress in sweet sorghum. Sequencing of 14 libraries (two biological replicates for each stage). Each replicate yielded an average of 86 million reads per sample for developmental stages and drought stressed samples yielded an average of 74 million reads per sample .
Project description:Sorghum plants (Btx623 background) were grown in a glasshouse between March and May 2014. At panicle emergence, two biological replicates of flag leaf tissue and two biological replicates of emerging panicle tissue were harvested and used for RNA extraction. Btx623 is a non-shattering Sorghum accession, thus in the future we would like to add additional samples from accessions with varying degrees of seed shattering. This dataset will be useful for future comparisons of 1) shattering individuals at these stages and 2) additional flowering developmental time points in a variety of accessions (http://www.rnaseqforthenextgeneration.org/profiles/carrie-thurber.html#research)