Project description:This study is a time course of growth induction (0, 12, 24, 48, and 72 hrs) following the breaking of paradormancy in underground buds of the perennial weed leafy spurge (Euphorbia esula). Keywords: Time course, growth induction, apical dominance, paradormancy, root buds, leafy spurge
Project description:Transcriptome changes were investigated for Euphorbia esula (leafy spurge) seeds with a focus on the effect of constant and diurnal fluctuating temperature on dormancy and germination. Leafy spurge seeds do not germinate when incubated for 21 days at 20°C constant temperatures, but nearly 30% germinate after 21 days under fluctuating temperatures 20:30°C (16:8 h). Incubation at 20°C for 21 followed by 20:30°C resulted in approximately 63% germination in about 10 days. A cDNA microarray representing approximately 22,000 unique sequences was used to profile transcriptome changes.
Project description:Transcriptome changes were investigated for Euphorbia esula (leafy spurge) seeds with a focus on the effect of constant and diurnal fluctuating temperature on dormancy and germination. Leafy spurge seeds do not germinate when incubated for 21 days at 20°C constant temperatures, but nearly 30% germinate after 21 days under fluctuating temperatures 20:30°C (16:8 h). Incubation at 20°C for 21 followed by 20:30°C resulted in approximately 63% germination in about 10 days. A cDNA microarray representing approximately 22,000 unique sequences was used to profile transcriptome changes. Labeled cDNA was prepared from total RNA using the Alexa Fluor cDNA labeling kit (Invitrogen, Carlsbad, CA) according to manufacture's protocols. Labeled cDNAs were hybridized to a custom made 23 K element microarray that contained 19,808 unigenes from the leafy spurge EST database and an additional 4,129 unigenes from a cassava EST database. A rolling circle dye swap hybridization scheme was used to compare gene expression between samples. There were three biological and two technical replications for each treatment. Microarray hybridization was visualized using a GenPix 4000B scanner (Axon Instruments/Molecular Devices Corp., Sunnyvale, CA) and spot intensities and background was quantified using GenPix Pro software. Hybridization intensities were log2 transformed, and arrays were centered and normalized against each other.
Project description:Glyphosate is known to inhibit 5-enolpyruvylshikimate-3-phosphate synthase of the chorismate biosynthetic pathway, and chorismate is a precursor to aromatic amino acids, auxin, and many other secondary products. Although the perennial weed leafy spurge (Euphorbia esula L.) is considered glyphosate tolerant, glyphosate is often used as part of an integrated pest management program in non-cultivated ecosystems of North America. Part of its tolerance is attributed to escape through an abundance of underground adventitious buds (UABs). Sub-lethal concentrations of foliar applied glyphosate leads to new shoot growth from UABs that have a stunted and/or bushy phenotype after growth-inducing decapitation. To gain insights into glyphosateM-bM-^@M-^Ys impact on molecular mechanisms associated with the stunted and bushy phenotype, we obtained global transcriptome abundance using RNAseq from a subsequent generation of aerial shoots derived from crown buds of glyphosate-treated and -untreated leafy spurge. We further correlated transcript abundance to accumulation of shikimate and phytohormones from the same samples to elucidate interactions. Abundance of shikimate was similar in subsequent generations of aerial shoots generated from crown buds of treated and untreated plants and is likely not a direct factor leading to the stunted and bushy phenotype. However, the results do suggest that transcripts involved in auxin transport and signaling and crosstalk with other phytohormones likely play a role in the bushy phenotype. The results of this study provide some insights for identifying new targets for manipulation of plant growth and development. Transcriptome and metabolite profiling are obtained for aerial tissues derived from crown buds of foliar glyphosate-treated and control (2.24 or 0 kg/ha active ingredient glyphosate + 0.25% v/v surfactant) leafy spurge plants. Each experiment included 4 biological replicates.
Project description:Glyphosate is known to inhibit 5-enolpyruvylshikimate-3-phosphate synthase of the chorismate biosynthetic pathway, and chorismate is a precursor to aromatic amino acids, auxin, and many other secondary products. Although the perennial weed leafy spurge (Euphorbia esula L.) is considered glyphosate tolerant, glyphosate is often used as part of an integrated pest management program in non-cultivated ecosystems of North America. Part of its tolerance is attributed to escape through an abundance of underground adventitious buds (UABs). Sub-lethal concentrations of foliar applied glyphosate leads to new shoot growth from UABs that have a stunted and/or bushy phenotype after growth-inducing decapitation. To gain insights into glyphosate’s impact on molecular mechanisms associated with the stunted and bushy phenotype, we obtained global transcriptome abundance using RNAseq from a subsequent generation of aerial shoots derived from crown buds of glyphosate-treated and -untreated leafy spurge. We further correlated transcript abundance to accumulation of shikimate and phytohormones from the same samples to elucidate interactions. Abundance of shikimate was similar in subsequent generations of aerial shoots generated from crown buds of treated and untreated plants and is likely not a direct factor leading to the stunted and bushy phenotype. However, the results do suggest that transcripts involved in auxin transport and signaling and crosstalk with other phytohormones likely play a role in the bushy phenotype. The results of this study provide some insights for identifying new targets for manipulation of plant growth and development.
Project description:This study investigated changes in the transcriptome of outdoor grown leafy spurge crown buds as they progress from paradormancy in August and September into endo dormancy in October through to ecodormancy in November and December. Keywords: Dormancy leafy spurge adventitious-buds