High density and limiting nitrogen response in rice
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ABSTRACT: Physiological changes underlying high density stress were examined in Oryza sativa plants over the course of a life cycle by assessing differences in gene expression. Moreover, the nitrogen limitation was examined in parallel with high density stress to gain a better understanding of physiological responses specific to high density stress.
Project description:Physiological changes underlying high density stress were examined in Oryza sativa plants over the course of a life cycle by assessing differences in gene expression. Moreover, the nitrogen limitation was examined in parallel with high density stress to gain a better understanding of physiological responses specific to high density stress. RNA was extracted from 21 and 31 days old plants. The plants were grown under four conditions: sufficient nitrogen (10mM N) and low density (six plants per bin), limiting nitrogen (3mM N) and low density, sufficient nitrogen and high density (40 plants per bin), limiting nitrogen and high density. Three biological replicates were sampled from each growth condition.
Project description:Os02g31890 encodes a dehydration-responsive transcription factor (named ´ARID´) from rice (Oryza sativa, cv. Dongjin). Expression profiling was performed 90 min after the start of dehydration stress in roots of Oryza sativa wild-type plants (cv. Dongjin) and a knock-out (i.e. arid) mutant.
Project description:Transcriptional profiling of a Oryza sativa L. land race Lijiangxintuanheigu (LTH) under cold stress (8℃) comparing to control (26℃)
Project description:Drought often compromises yield in non-irrigated crops such as rainfed rice, imperiling the communities that depend upon it as a primary food source. In this study, two cultivated species (Oryza sativa cv. Nipponbare and Oryza glaberrima cv. CG14) and an endemic, perennial Australian wild species (Oryza australiensis) were grown in soil at 40% field capacity for 7-d (drought). The hypothesis was that the natural tolerance of O. australiensis to erratic water supply would be reflected in a unique proteomic profile. Leaves from droughted plants and well-watered controls were harvested for label-free quantitative shotgun proteomics. Physiological and gene ontology analysis confirmed that O. australiensis is responded uniquely to drought, with superior leaf water status and enhanced levels of photosynthetic proteins. Moreover, distinctive patterns of expression of proteins in drought were observed across the entire O. australiensis proteome. An intermediate impact of drought on photosynthetic and stress-response proteins is reported in O. glaberrima relative to O. sativa but the drought response was most striking in O. australiensis. For example, photosynthetic proteins decreased when O. sativa after drought, while a narrower range of stress-responsive proteins was up-regulated. Distinctive proteomic profiles and the expression levels of individual proteins with specific functions in response to drought in O. australiensis indicate the importance of this species as a source of stress tolerance genes.
Project description:Oryza sativa cv. Nipponbare was engineered to over-express a barley alanine aminotransferase (alaAT) gene using the promoter (OsANT1) from a rice aldehyde dehydrogenase gene that expresses in roots. We are using biotechnology to improve the nitrogen use efficiency of rice by over-expressing alaAT in a tissue specific (root) manner. The AlaAT enzyme is a reversible aminotransferase that is linked to both C and N metabolism since it uses pyruvate plus glutamate to produce alanine and 2-oxoglutarate, and visa versa.
Project description:Comparative transcriptome sequencing in leaf and root tissues of Control and Salt-treated Oryza sativa generated 52.2 and 17.29 million high-quality reads.
Project description:Nitrogen (N) and phosphorus (P) are two primary components of fertilizers for crop production. Coordinated acquisition and utilization of N and P are crucial for plants to achieve nutrient balance and optimal growth in a changing rhizospheric nutrient environment. However, little is known about how N and P signaling pathways are integrated. We performed transcriptomic analyses and physiological experiments to explore gene expression profiles and physiological homeostasis in the response of rice (Oryza sativa) to N and P deficiency. We determined that the transcript levels of 763 core genes changed under both N or P starvation conditions. Among these core genes, we focused on the transcription factor gene NITRATE-INDUCIBLE, GARP-TYPE TRANSCRIPTIONAL REPRESSOR 1 (NIGT1) and show that its encoded protein is a positive regulator of P homeostasis and a negative regulator of N acquisition in rice. These results provide new clues about the mechanisms underlying the interaction between plant N and P starvation responses.
Project description:Maize (Zea mays L.) is one of the major cereal crops worldwide. Increasing planting density is an effective way to improve crop yield. However, plants grown under high-density conditions compete for water, nutrients, and light, which often leads to changes in productivity. To date, few studies have determined the transcriptomic differences in maize leaves in response to different planting densities. This study examined the whole-genome expression patterns in the leaves of maize planted under high and low densities to identify density-regulated genes. Leaves at upper, ear, and lower stem nodes were collected at the grain-filling stage of the maize hybrid Xianyu335 grown under low-density planting and high-density planting. In total, 72, 733, and 1,739 differentially expressed genes (DEGs) were identified in the respective upper, ear, and lower leaves under HDP. Upregulated and downregulated DEGs in the upper and lower leaves were similar in number, whereas upregulated DEGs in the ear leaves were significantly higher in number than the downregulated DEGs. Functional analysis indicated that genes responding to HDP-related stresses were mediated by pathways involving four phytohormones responsible for metabolism and signaling, osmoprotectant biosynthesis, transcription factors, and fatty acid biosynthesis and protein kinases, which suggested that these pathways are affected by the adaptive responses mechanisms underlying the physiological and biochemical responses of the leaves of maize planted at high density.
Project description:Investigation of whole genome gene expression level changes in a Azospirillum lipoferum 4B associated to artificial roots, Oryza sativa japonica cv. Cigalon roots and Oryza sativa japonica cv. Nipponbare roots, compared to the strain grown in liquid culture.