Phosphorus (P) is a major plant nutrient. It is transported into and allocated inside plants by four families of phosphate transporters (PHT1 to PHT4) with high or low affinity to phosphate. Here, we studied whole-plant P uptake kinetics and expression profiles of members of the PHT families under high, intermediate and low P availability in the woody crop poplar (Populus × canescens) in relation to plant performance.Poplars exhibited strong growth reduction and increased P use efficiency in res ...[more]
Project description:Populus x canescens was inoculated with Paxillus involutus and grown in a climate chamber for 13 weeks. Afterwards, plants were salt stressed for 18 additional days with 150 mM NaCl in the nutrient solution. This resulted in 4 different treatments: no mycorrhiza<br>control (NC), mycorrhiza/control (MC), no mycorrhiza/salt (NS), mycorrhiza/salt (MS).
Project description:Populus x canescens were kept in climate chambers for a growing period of 8 weeks. Afterwards, treatment started for five weeks in total. Plant were first treated with different daylength (long-days or short-days) under well-watered conditions. After 2 weeks, half of each daylength treatment was drought stressed while the other half was still well-watered. After further three weeks, all poplars were harvested and samples of developing and mature xylem were taken and directly frozen in liquid nitrogen. These samples were taken for RNA extraction and following RNA-sequencing.
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. Experiment 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:4 weeks old rooted plantlets of P. × canescens (Clone INRA717 1-B4) were cultivated in hydroponics in 2 l pots in Long Ashton nutrient solution in a culture room for 8 weeks before treatments started. Three treatments were applied to the plants: control treatment (-ABA), continuous 100 µM ABA treatment (+ABA) and discontinuous 100 µM ABA treatment (±ABA). ABA was fed to +ABA plants during the whole treatment period of 30 days. ABA was fed to ±ABA plants for three days in two weeks. Developing xylem and mature xylem were collected separately during the harvest and shortly frozen in liquid nitrogen. RNA was extracted from these samples and followed by RNA-sequencing.
Project description:affy_rnai_cadpoplar - affy_rnai_cadpoplars - This experiment aims to characterize global gene expression in young xylem of transgenic RNAi-CAD poplars in comparison to WT poplars. Cinnamyl Alcohol Dehydrogenase (CAD) is the final enzyme involved in the monolignol biosynthesis pathway. Transgenic poplars were produced using RNAi strategy (pHellsgate 8 vector, Helliwell and Waterhouse, 2003) and exhibited the expected phenotype (red xylem, reduced CAD activity).Biological question (15 lines max):This experiment aims to characterize global gene expression in young xylem of transgenic RNAi-CAD poplars in comparison to WT poplars. Cinnamyl AlcoholDehydrogenase (CAD) is the final enzyme involved in the monolignol biosynthesispathway.Transgenic poplars were produced using RNAi strategy (pHellsgate 8 vector, Helliwell and Waterhouse, 2003) and exhibited the expectedphenotype (red xylem, reduced CAD activity). -RNAi-CAD transgenic poplars were produced using hairpin RNAi strategy (pHellsgate 8 vector, Helliwell and Waterhouse, 2003). For this transcriptome anaylsis, 2 independent transgenic lines (named pHG8-CAD2 and pHG8-CAD19) from the same transformation procedure were used as biological repeats. Four-month-old poplar plants were inclined at 30° in the greenhouse and sampled after 26 days. Young differentiating xylem originating from the lower side of stems - opposite wood - (ODX) was sampled on each individual tree by scrapping slightly the debarked stem with a scalpel. Samples were immediately flash frozen in liquid nitrogen, ground with mortar and pestle, and total RNAs were extracted from fine ground powder using the QIAGEN miRNeasy kit according to the manufacturer. One Affymetrix slide corresponds to a pool of RNA samples from 2-4 individual trees (WT, RNAi-CAD transgenic lines 2 and 19). Total number of slides = 2 genotypes (WT/RNAi line) x 1 tissue x 2 biological replicates = 4 slides were done. 4 arrays - poplar; normal vs rnai mutant comparaison
Project description:Because nitrogen (N) nutrition is a key determinant of plant growth, we explored the role of N availability in grafted grapevine development. Vitis vinifera cv. Cabernet Sauvignon was grafted on two rootstock genotypes known to confer high (1103 Paulsen, 1103P) and low (Riparia Gloire de Montpellier, RGM) vigour. One-year-old plants were cultivated in sand-filled pots in a greenhouse and irrigated with the control nutrient solution for 15 days of acclimation (1.6 mM N). At the end of the acclimation period (0 days post treatment (dpt)), the plants were divided in two groups of 5 plants per combination and irrigated with nutrient solutions varying only in their nitrate concentration (0.8 mM (Nitrate -) and 2.45 mM (Nitrate +)). Roots were harvested at 15 and 60 dpt. Gene expression profiling was done using the Nimblegen whole genome array with 3 biological replicates per condition to analyze the combined effect of N treatment and rootstock genotype on gene expression.
Project description:Pierce’s disease, caused by the bacterium Xylella fastidiosa, is one of the most devastating diseases of cultivated grapes. To test the long-standing hypothesis that Pierce’s disease results from pathogen-induced drought stress, we used the Affymetrix Vitis GeneChip to compare the transcriptional response of Vitis vinifera to Xylella infection, water deficit, or a combination of the two stresses. The results reveal a massive redirection of gene transcription involving 822 genes with a minimum 2-fold change (p<0.05), including the upregulation of transcripts for phenylpropanoid and flavonoid biosynthesis, pathogenesis related (PR) proteins, absisic acid (ABA)/jasmonic acid (JA)-responsive transcripts, and down-regulation of transcripts related to photosynthesis, growth and nutrition. Although the transcriptional response of plants to Xylella infection was largely distinct from the response of healthy plants to water stress, we find that 138 of the pathogen-induced genes exhibited a significantly stronger transcriptional response when plants were simultaneously exposed to infection and drought stress, suggesting a strong interaction between disease and water deficit. This interaction between drought stress and disease was mirrored in planta at the physiological level for aspects of water relations and photosynthesis, and in terms of the severity of disease symptoms and the extent of pathogen colonization, providing a molecular correlation of the classical concept of the disease triangle where environment impacts disease severity. Mature leaves were sampled from 2-year old V. vinifera cv. Cabernet sauvignon clone 8 vines 4 and 8 weeks post-mock or inoculation with Xylella fastidiosa (Pierce's disease). Vines were grown in growth chambers under non-water limiting and water limiting conditions (moderate and severe water stress)