Project description:To investigate possible genetic basis of alkali tolerance in rice, we generated an introgressed rice line (K83) with significantly enhanced tolerance to alkali stress than its recipient parental cultivar (Jijing88). By using microarray analysis, we examined global gene expression profiles in K83 and Jijing88, found more than 1,200 genes were constitutively differentially expressed in K83 compared with Jijing88, with 572 up- and 654 down-regulated. Upon alkali treatment, a total of 347 genes in K83 were found up- and 156 down-regulated in K83, compared with 591 and 187 respectively in Jijing88. Seven-day-old uniform-sized seedlings grown in hydroponic medium were transferred to fresh hydroponic medium alone or containing 50 mM alkali salts. Shoots were harvested 24 h after transfer and 10 shoots were pooled for microarray analysis.
Project description:To investigate possible genetic basis of alkali tolerance in rice, we generated an introgressed rice line (K83) with significantly enhanced tolerance to alkali stress than its recipient parental cultivar (Jijing88). By using microarray analysis, we examined global gene expression profiles in K83 and Jijing88, found more than 1,200 genes were constitutively differentially expressed in K83 compared with Jijing88, with 572 up- and 654 down-regulated. Upon alkali treatment, a total of 347 genes in K83 were found up- and 156 down-regulated in K83, compared with 591 and 187 respectively in Jijing88.
Project description:Soil alkalinity greatly affects plant growth and crop productivity. Although RNA-Seq analyses have been conducted to investigate genome-wide gene expression in response to alkaline stress in many plants, the expression of alkali-responsive genes in rice has not previously investigated. In this study, the transcriptomic data were compared between an alkaline-tolerant [WD20342 (WD)] and an alkaline-sensitive [Caidao (CD)] rice cultivar under control and alkaline stress conditions. A total of 962 important alkali-responsive (IAR) genes from highly differentially expressed genes (DEGs) were identified, including 28 alkaline-resistant cultivar-related genes, 771 alkaline-sensitive cultivar-related genes and 163 cultivar-non-specific genes. Gene ontology (GO) analysis suggested the enrichment of IAR genes involved in response to various stimuli or stresses. According to KEGG pathway analysis, the IAR genes were related primarily to plant hormone signal transduction and biosynthesis of secondary metabolites. Additionally, among these 962 IAR genes, 74 were transcription factors and 15 occurred with differential alternative splicing between the different samples after alkaline treatment. Our results provide a valuable resource on alkali-responsive genes and should benefit the improvement of alkaline stress tolerance in rice.
Project description:We present here a transcriptome dataset of millet seedling leaves based on RNA-seq technology. The purpose of this study was to mine the salt and alkali tolerance genes of millet and further explore the mechanism of salt and alkali tolerance of millet. We selected 18 representative samples and conducted in-depth sequencing using the latest sequencing platform to ensure the accuracy and reliability of the data.
Project description:Salt stress, especially saline-alkali stress, has seriously negative effect on citrus production. Ziyang xiangcheng (Citrus junos Sieb.) (Cj) has been reported as a saline-alkali stress and iron deficiency tolerant citrus rootstock. However, the molecular mechanism of its saline-alkali stress tolerance is still not clear. Two citrus rootstocks and one navel orange scion, Cj, Poncirus trifoliate (Poncirus trifoliata (L.) Raf.) (Pt) and ‘Lane Late’ navel orange (Citrus sinensis (L.) Osb.) (LL), were used in this study. The grafted materials Cj+LL and Pt+LL grown in calcareous soil were used to identify genes and pathways responsive to saline-alkali stress using RNA-seq. The seedlings of Cj and Pt grown in the solutions with different gradient pH value were used to perform a supplement experiment. Comprehensively analyzing the data of RNA-seq, physiology and biochemistry, agronomic traits and mineral elements of Cj+LL, Pt+LL, Cj and Pt, several candidate pathways and genes were identified to be highly regulated under saline-alkali stress. Here, we propose citrate is important for the tolerance to iron deficiency and the jasmonate (JA) biosynthesis and signal transduction pathway may play a crucial role in tolerance to saline-alkali stress in citrus by interacting with other plant hormones, calcium signaling, ROS scavenging system and lignin biosynthesis.
Project description:we characterized the rice alkaline tolerant mutant, alt1. Map-based cloning revealed that alt1 harbors a mutation in a putative chromatin remodeling ATPase gene. ALT1-RNAi transgenic plants mimicked the alt1 phenotype, exhibiting tolerance to alkali stress in a transcript dosage-dependent manner. We found that the predicted ALT1 protein belonged to the Ris1 subgroup of the Snf2 family and was localized in the nucleus. qRT-PCR analysis showed that ALT1 was predominantly expressed in leaf blades and sheaths, and that ALT1 transcription was rapidly suppressed after alkaline treatment. These results support the notion that ALT1 is a negative regulator of alkaline tolerance. Roots of two-leaf stage alt1 and WT seedlings grown under normal conditions were sampled for microarray analysis. The transcriptomic profiles were investigated using an Agilent-015241 Rice Gene Expression 4×44 K Microarray (Agilent Technology) containing 32,325 probes corresponding to cDNA, 6,934 probes corresponding to expressed sequence tags (ESTs), and 2,612 probes corresponding to gene predicted loci, respectively, with three independent biological replicates. Roots of two-leaf stage alt1 and WT seedlings grown under normal conditions were sampled for microarray analysis
Project description:we characterized the rice alkaline tolerant mutant, alt1. Map-based cloning revealed that alt1 harbors a mutation in a putative chromatin remodeling ATPase gene. ALT1-RNAi transgenic plants mimicked the alt1 phenotype, exhibiting tolerance to alkali stress in a transcript dosage-dependent manner. We found that the predicted ALT1 protein belonged to the Ris1 subgroup of the Snf2 family and was localized in the nucleus. qRT-PCR analysis showed that ALT1 was predominantly expressed in leaf blades and sheaths, and that ALT1 transcription was rapidly suppressed after alkaline treatment. These results support the notion that ALT1 is a negative regulator of alkaline tolerance. Roots of two-leaf stage alt1 and WT seedlings grown under normal conditions were sampled for microarray analysis. The transcriptomic profiles were investigated using an Agilent-015241 Rice Gene Expression 4×44 K Microarray (Agilent Technology) containing 32,325 probes corresponding to cDNA, 6,934 probes corresponding to expressed sequence tags (ESTs), and 2,612 probes corresponding to gene predicted loci, respectively, with three independent biological replicates.
Project description:Alkali-salinity is a major abiotic stress that limits plant growth and productivity. Studying mechanisms of alkali-salinity tolerance in halophytic plants will provide valuable information for underlying plant alkali-salinity tolerance. Puccinellia tenuiflora is considered as an ideal model plant for studying the alkali-salinity tolerant mechanisms in plants. In this study, the NaHCO3-responsive molecular mechanisms in P. tenuiflora leaves were investigated using a combined physiological and proteomic approaches. Our results implied some specific NaHCO3-responsive mechanisms in leaves from P. tenuiflora. They are (1) reduction of photosynthesis attributed to the decrease of the abundance of Calvin cycle enzymes, (2) accumulation of Na+ and K+ caused ion-specific stress, (3) accumulation of proline, soluble sugar and betaine enhanced the ability of osmotic regulation, (4) diverse reactive oxygen species (ROS) scavenging mechanisms under different NaHCO3 concentrations, and (5) alternative protein synthesis and processing strategies in chloroplast and cytoplasm. All these provide important evidence for understanding NaHCO3-responsive mechanisms in P. tenuiflora.
Project description:Alkali stress is an important means of inactivating undesirable pathogens in a wide range of situations, ranging from environmental cleaning of food processing environments, to the phagolysosomal killing of cells engulfed by mammalian phagocytes. Unfortunately, L. monocytogenes can launch an alkaline tolerance response (AlTR), significantly increasing persistence of the pathogen in such environments. This study compared the transcriptome patterns of alkali stressed and non alkali stressed L. monocytogenes 10403S cells, to elucidate the mechanisms by which this important pathogen adapts and/or grows during short or long-term alkali stress. Transcription profiles associated with alkali shock (AS) responses were obtained by DNA microarray analysis of mid-exponential cells suspended in pH 9 media for 15, 30 or 60 min. Transcription profiles associated with alkali adaptation (AA) were obtained by DNA microarray analysis of cells grown to mid-exponential phase in pH 9 media . Comparison of AS and AA transcription profiles with profiles from control (pH 7.0) cells identified over 2,000 genes that were differentially expressed under alkaline conditions. Rapid (15min) changes in expression included upregulation of genes encoding for multiple metabolic pathways, (including those associated with Na+/H+ antiporters), ABC transporters of functional compatible solutes such as carnitine, motility and virulence-associated genes as well as the σB controlled stress resistance network. Slower (30min and more) responses to AS and adaptation during growth in alkaline conditions (AA), included modest changes in mRNA concentrations, and genes involved in proton export. Keywords: Time course study of gene expression response to alkaline shock and adaptation
Project description:Drought is a major environmental constraint affecting physiological, biochemical and molecular changes of crops, causing loss in crop productivities. Understanding the molecular mechanisms of drought tolerance is important for crop biotechnology. Here, we report that the rice (Oryza sativa) homeodomain-leucine zipper class IV transcription factor gene, Rice outermost cell-specific gene 10 (Roc10), improves drought tolerance and grain yield by increasing lignin accumulation in ground tissues of rice plants. Overexpression of Roc10 significantly enhanced drought tolerance of transgenic rice plants at the vegetative stages of growth with highly effective photosystem and reduction of water loss rate as compared with non-transgenic control and RNAi plants. More importantly, Roc10 overexpression plants had higher drought tolerance at the reproductive stage of growth with higher grain yield over controls under field-drought conditions. We identified downstream and putative target genes of Roc10 by using RNA-seq and ChIP-seq data of rice shoots. Roc10 overexpression elevated the expression levels of lignin biosynthetic genes in shoots with a concomitant increase in accumulation of lignin. The overexpression and RNAi lines showed opposite patterns of lignin accumulation. The Roc10 is mainly expressed in the outer cell layers including epidermis and vasculature of shoots that coincides with areas of increased lignification. Furthermore, the Roc10 was found to directly bind to the promoter of PEROXIDASEN/PEROXIDASE38, a key gene in lignin biosynthesis. Together, our findings suggested that the Roc10 confers drought stress tolerance by enhancing lignin biosynthesis in ground tissues of rice plants.