Project description:These experiments were to investigate changes in gene expression associated with maize competition for light when grown at double normal population density or under 60% shaded conditions as opposed to when maize is grown under normal field conditions.
Project description:These experiments were to investigate changes in gene expression associated with maize competition for light when grown at double normal population density or under 60% shaded conditions as opposed to when maize is grown under normal field conditions. Three biological replicates (collected from separate field plots) comprised of pooled samples of 4 plants from each treatment were hybridized in a rolling circle dye swap hybridization screen.
Project description:This was a comparative transcriptome analysis by using high throughput sequencing. To assess the effects of heat stress on maize alternative splicing we used a controlled environment facility called the Enviratron to simulate field conditions. For our experiments, maize plants were subjected to conditions simulating normal diurnal rhythms of light and temperature, with increasing maximal daily temperature (MDT). Maize plants were grown continuously under four different temperature regimes with simulated morning temperatures ramped up over 6 hr to the MDT of 31°C, 33°C, 35°C or 37°C and simulated evening/night time temperatures ramped down over 8 hr to 10°C below the MDT. We tracked the alternative splicing events of maize W22 seedlings grow under different temperatures (MDT of 31°C, 33°C, 35°C or 37°C) to evaluate how different MDTs affect the program of gene alternative splicing in maize. RNA was extracted from small strips of leaf lamina excised from the first fully expanded leaf of V4 and V5 W22 plants (at 20 and 27 DAG, respectively). Plants were sampled in triplicates.
Project description:Plants and rhizosphere microbes rely closely on each other, with plants supplying carbon to bacteria in root exudates, and bacteria mobilizing soil-bound phosphate for plant nutrition. When the phosphate supply becomes limiting for plant growth, the composition of root exudation changes, affecting rhizosphere microbial communities and microbially-mediated nutrient fluxes. To evaluate how plant phosphate deprivation affects rhizosphere bacteria, Lolium perenne seedlings were root-inoculated with Pseudomonas aeruginosa 7NR, and grown in axenic microcosms under different phosphate regimes (330 uM vs 3-6 uM phosphate). The effect of biological nutrient limitation was examined by DNA microarray studies of rhizobacterial gene expression.
Project description:Elevated atmospheric CO2 can influence the structure and function of rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizosphere via root exudation. In these studies we investigated the transcriptional responses of Bradyrhizobium japonicum cells growing in the rhizosphere of soybean plants exposed to elevated atmospheric CO2. Transciptomic expression profiles indicated that genes involved in carbon/nitrogen metabolism, and FixK2-associated genes, including those involved in nitrogen fixation, microanaerobic respiration, respiratory nitrite reductase, and heme biosynthesis, were significantly up-regulated under conditions of elevated CO2, relative to plants and bacteria grown under ambient CO2 growth conditions. The expression profile of genes involved in lipochitinoligosaccharide Nod factor biosynthesis and negative transcriptional regulators of nodulation genes, nolA and nodD2, were also influenced by plant growth under conditions of elevated CO2. Taken together, results of these studies indicate that growth of soybeans under conditions of elevated atmospheric CO2 influences gene expressions in B. japonicum in the soybean rhizosphere, resulting in changes to carbon/nitrogen metabolism, respiration, and nodulation efficiency. Bradyrhizobium japonicum strains were grown in the soybean rhizosphere under two different CO2 concentrations. Transcriptional profiling of B. japonicum was compared between cells grown under elevated CO2 and ambient conditions. Four biological replicates of each treatment were prepared, and four microarray slides were used for each strain.
Project description:A continuous gene expression profiling of roots was performed at regular interval during a 48-hr period in 2 different growth stages to characterize the diurnal and circadian gene expression profile of rice growth under natural field conditions. Root was collected at 2-hr intervals during a 48-hr period at 2 different growth stages corresponding to early and late vegetative stages. All samples were obtained from rice plants grown in the field during the 2008 cultivation season.
Project description:Iron deficiency is a yield-limiting factor and a worldwide problem for crop production in many agricultural regions, particularly in aerobic and calcareous soils. Graminaceous species, like maize, improve Fe acquisition through the release of phytosiderophores (PS) into the rhizosphere and the following uptake of Fe(III)-PS complexes through specific transporters. Transcriptional profile obtained by roots 12-d-old maize plants under Fe starvation for 1 week (Fe-deficient; 19-d-old plants) were compared with the transcriptional profile obtained by roots of 12-d-old maize plants grown in a nutrient solution containing 100 μM Fe-EDTA for 1 week (Fe-sufficient; 19-d-old plants).
Project description:This was a comparative transcriptome analysis by using high throughput sequencing. To assess the effects of heat stress on maize we used a controlled environment facility called the Enviratron to simulate field conditions. For our experiments, maize plants were subjected to conditions simulating normal diurnal rhythms of light and temperature, with increasing maximal daily temperature (MDT). Maize plants were grown continuously under four different temperature regimes with simulated morning temperatures ramped up over 6 hr to the MDT of 31°C, 33°C, 35°C or 37°C and simulated evening/night time temperatures ramped down over 8 hr to 10°C below the MDT. We tracked the gene expression events of maize W22 seedlings grow under different temperatures (MDT of 31°C, 33°C, 35°C or 37°C) to evaluate how different MDTs affect the program of gene expression in maize. At the same time, we analyzed the effects of temperature on gene expression in bzip60-2 and W22 V4 plants (20 DAG) and V5 plants (27 DAG) in the Enviratron as the temperature reached its MDT to investigate whether and how bZIP60 confers heat stress tolerance in maize. RNA was extracted from small strips of leaf lamina excised from the first fully expanded leaf of V4 and V5 W22 plants (at 20 and 27 DAG, respectively). Plants were sampled in triplicates.
Project description:Elevated atmospheric CO2 can influence the structure and function of rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizosphere via root exudation. In these studies we investigated the transcriptional responses of Bradyrhizobium japonicum cells growing in the rhizosphere of soybean plants exposed to elevated atmospheric CO2. The results of microarray analyses indicated that atmospheric elevated CO2 concentration indirectly influences on expression of large number of Bradyrhizobium genes through soybean roots. In addition, genes involved in C1 metabolism, denitrification and FixK2-associated genes, including those involved in nitrogen fixation, microanaerobic respiration, respiratory nitrite reductase, and heme biosynthesis, were significantly up-regulated under conditions of elevated CO2 in the rhizosphere, relative to plants and bacteria grown under ambient CO2 growth conditions. The expression profile of genes involved in lipochitinoligosaccharide Nod factor biosynthesis and negative transcriptional regulators of nodulation genes, nolA and nodD2, were also influenced by plant growth under conditions of elevated CO2. Taken together, results of these studies indicate that growth of soybeans under conditions of elevated atmospheric CO2 influences gene expressions in B. japonicum in the soybean rhizosphere, resulting in changes to carbon/nitrogen metabolism, respiration, and nodulation efficiency.