Project description:This series analyses germinating Lepidium sativum seeds with both temporal and spatial detail. This is a cross species microarray normalisation on Arabidopsis thaliana chips. Performed as part of the vSEED project Lepidium seeds were dissected into four compartments at seven time points during seed germination. The compartments were the micropylar endosperm (CAP), the non-micropylar endosperm (NME), the radicle and lower hypocotyl (RAD) and the cotyledons (COT). At testa and endosperm rupture the seeds were split into pre- and post- ruptured populations. Dry seeds were also sampled: as a whole seed (DRY), the radicle and endosperm part (DRYRC) and the dry seed part containing the non-micropylar endosperm and part of the cotyledons (DRYNMC).
Project description:This series analyses germinating Lepidium sativum seeds with both temporal and spatial detail. This is a cross species microarray normalisation on Arabidopsis thaliana chips. Performed as part of the vSEED project
Project description:Molecular responses of plants to natural phytotoxins comprise more general and com-pound-specific mechanisms. How phytotoxic chalcones and other flavonoids inhibit seedling growth was widely studied, but how they interfere with seed germination is largely unknown. The dihydrochalcone and putative allelochemical myrigalone A (MyA) inhibits seed germination and seedling growth. Transcriptome (RNAseq) and hormone analyses of Lepidium sativum seed re-sponses to MyA were compared to other bioactive and inactive compounds. MyA treatment of imbibed seeds triggered the phased induction of a detoxification programme, altered gibberellin, cis-(+)-12-oxophytodienoic acid and jasmonate metabolism, and affected the expression of hor-mone transporter genes. The MyA-mediated inhibition involved interference with the antioxidant system, oxidative signalling, aquaporins and water uptake, but not uncoupling of oxidative phosphorylation or p-hydroxyphenylpyruvate dioxygenase expression/activity. MyA specifically affected the expression of auxin-related signalling genes, and various transporter genes, including for auxin transport (PIN7, ABCG37, ABCG4, WAT1). Responses to auxin-specific inhibitors further supported the conclusion that MyA interferes with auxin homeostasis during seed germination. Comparative analysis of MyA and other phytotoxins revealed differences in the specific regulatory mechanisms and auxin transporter genes targeted to interfere with auxin homestasis. We conclude that MyA exerts its phytotoxic activity by multiple auxin-dependent and independent molecular mechanisms.
Project description:An experiment was performed to compare genomic DNA from Lepidium sativum and Arabidopsis thaliana, on microarrays spotted with CATMA Arabidopsis GSTs
Project description:An experiment was performed to compare global transcription patterns in two tissues of Lepidium sativum seeds at different times during imbibition leading up to, but not including, radicle protrusion from the seed (e.g. germination). RNA extractions from the two tissues were hybridised to CATMA Arabidopsis microarrays. The two tissues were the radicle and the micropylar endosperm cap that covers it. The interaction of these two tissues is thought to control the timing of germination though alterations in the extensibility of the radicle and the physical resistance of the micropylar endosperm cap to radicle penetration.
Project description:An experiment was performed to compare global transcription patterns in three tissues of Lepidium sativum seeds at different times during imbibition leading up to, but not including, radicle protrusion from the seed (e.g. germination). RNA extractions from the three tissues were hybridised to CATMA Arabidopsis microarrays. The three tissues were the radicle, the micropylar endosperm cap that covers it, and the non-micropylar endosperm. The interaction of the first two of these tissues is thought to control the timing of germination though alterations in the extensibility of the radicle and the physical resistance of the micropylar endosperm cap to radicle penetration.
