Project description:The suppression of sprout growth is critical for the long-term storage of potato tubers. 1,4-dimethylenapthlene (DMN) is a new class of sprout control agent but the metabolic mode of action for this compound has yet to be elucidated. Changes in transcriptional profiles of meristems isolated from potato tubers treated with the DMN were investigated using an Agilent 44K 60-mer-oligo microarray. RNA was isolated from nondormant Russet Burbank meristems isolated from tubers treated with DMN for three days or activated charcoal as a control. RNA was used to develop probes that were hybridized against a microarray developed by the Potato Oligo Chip Initiative (POCI). Analysis of the array data was conducted in two stages: total array data was examined using a linear model and the software limma and pathway analysis was conducted by linking the potato sequences to the Arabidopsis thaliana. DMN elicited a change in a number of transcripts associated with cold responses, water regulation, salt stress and osmotic adjustment. Additionally, repression of auxin signaling and transport were observed in DMN-treated tubers, and connections between DMN treatment and repression of FT through mi156 regulation were indicated. DMN also resulted in a repression of cyclin or cyclin-like transcripts. DMN also resulted in a 50% decrease in thymidine incorporation suggesting a repression of the S-phase of the cell cycle. QT-PCR analysis demonstrated that DMN increased transcripts for the cell cycle inhibitors KRP1 and KRP2. We conclude the DMN results in alteration of genes associated with cold responses and water regulation and maintenance of a G1/S-phase block possibly through the induction of the cell cycle inhibitors KRP1 andKRP2. Twelve samples, four treatments, three biological replicates Non dormant meristems as control (Control-rep), meristems isolated from tubers treated with water for three days (Control3Days-rep), meristems treated with DMN for three days (DMN3Days-rep), meristems treated with DMN for three days and then vented to the air for two days (DMN3Days-2Out-rep).
Project description:The experiment followed transcriptional changes during potato tuber induction from a stolon tip to a tuber. Samples were taken at stage 1, stage 3, stage 4 and stage 5 according to Kloosterman et al., 2005
Project description:Although significant work has been undertaken regarding the response of model and crop plants to heat shock during the acclimatory phase, few studies have examined the steady state response to the mild heat stress encountered in temperate agriculture. In the present work we therefore exposed tuberising potato plants to mildly elevated temperatures (30/20C), day/night) for up to five weeks and compared tuber yield, physiological and biochemical responses, and leaf and tuber metabolomes and transcriptomes with plants grown under optimal conditions (22/16C). Growth at elevated temperature reduced tuber yield despite an increase in net foliar photosynthesis. This was associated with major shifts in leaf and tuber metabolite profiles, a significant decrease in leaf glutathione redox state and decreased starch synthesis in tubers. Furthermore, growth at elevated temperature had a profound impact on leaf and tuber transcript expression with large numbers of transcripts displaying a rhythmic oscillation at the higher growth temperature. RT-PCR revealed perturbation in the expression of circadian clock transcripts including StSP6A, previously identified as a tuberisation signal. Our data indicate that potato plants grown at moderately elevated temperatures do not exhibit classic symptoms of abiotic stress but that tuber development responds via a diversity of biochemical and molecular signals. In this submission we are looking at gene expression changes with respect to both temperature and time, every 4h over a 24h period whereby diurnal changes may be apparent.