Project description:For many potato cultivars, tuber yield is optimal at average day time temperatures in the range of 14-22 ⁰C. Further rises in ambient temperature can reduce or completely inhibit potato tuber production, with damaging consequences for both producer and consumer. In our previous work we observed that the steady-state expression level of the core circadian clock gene, TIMING OF CAB EXPRESSION 1 (TOC1), in potato tubers increased at moderately elevated temperature, whereas expression of the tuberisation signal gene StSP6A decreased along with tuber yield. In this study we investigated the potential roles of StTOC1 in linking environmental signalling and potato tuberisation. We show that transgenic lines with decreased expression of StTOC1 exhibit enhanced StSP6A transcript levels in tuberising stolons, and show changes in gene expression consistent with elevated tuber sink strength.
Project description:Effects of different parameters on the transcriptome in potato tuber: effect of infection with potato virus Y (PVY) on potato tubers, effects of two different storage times of potato tubers compared to no storage, effect of different storage temperature on potato tubers, effect of tuber necrosis development, effects of interactions between the above parameters. Lists of interaction factors and the differentially-expressed genes associated with each factor are provided as a series of Additional Files to this submission (see http://www.ebi.ac.uk/arrayexpress/files/E-MTAB-1071).
Project description:Potato (Solanum tuberosum L) is a natural host of Potato spindle tuber viroid (PSTVd) which can cause characteristic symptoms on developing plants including stunting phenotype and distortion of leaves and tubers. PSTVd is the type species of the family Pospiviroidae, it can replicate in the nucleus and the viroid RNA moves systemically in infected plants. Its KF440-2 strain can cause severe symptoms in potato. It is not well understood how the viroid can affect host genes for successful invasion and which genes show altered expression levels upon infection. In this study, we used a high-scale method to identify differentially expressed genes in potato. We have identified defence, stress and sugar metabolism related genes having altered expression levels upon infection. Additionally, hormone pathways connected genes showed up- or down-regulation. Our primary focus is on the identification of genes which can affect tuber formation as the viroid infection can strongly influence tuber development, especially tuber shape is affected. DWARF1/DIMINUTO, Gibberellin 7-oxidase and BEL5 protein were identified and validated which showed differential expression in viroid infected tissues suggesting that gibberellin and brassinosteroid pathways have a possible role in tuber development upon PSTVd infection.
Project description:Purpose: MicroRNAs (miRNAs) are ubiquitous components of endogenous plant transcriptome. miRNAs are small, single-stranded and ~21 nt long RNAs which regulate gene expression at the post-transcriptional level and are known to play essential roles in various aspects of plant development and growth. Previously, a number of miRNAs have been identified in potato through in silico analysis and deep sequencing approach. However, identification of miRNAs through deep sequencing approach was limited to a few tissue types and developmental stages. This study reports the identification and characterization of potato miRNAs in three different vegetative tissues and four stages of tuber development by high throughput sequencing. Results: Small RNA libraries were constructed from leaf, stem, root and four early developmental stages of tuberization and subjected to deep sequencing, followed by bioinformatics analysis. A total of 89 conserved miRNAs (belonging to 33 families), 147 potato-specific miRNAs (with star sequence) and 112 candidate potato-specific miRNAs (without star sequence) were identified. The digital expression profiling based on TPM (Transcripts Per Million) and qRT-PCR analysis of conserved and potato-specific miRNAs revealed that some of the miRNAs showed tissue specific expression (leaf, stem and root) while a few demonstrated tuberization stage-specific expressions. Targets were predicted for identified conserved and potato-specific miRNAs, and predicted targets of four conserved miRNAs, miR160, miR164, miR172 and miR171, which are ARF16 (Auxin Response Factor 16), NAM (NO APICAL MERISTEM), RAP1 (Relative to APETALA2 1) and HAIRY MERISTEM (HAM) respectively, were experimentally validated using 5M-bM-^@M-2RLM-RACE (RNA ligase mediated rapid amplification of cDNA ends). Gene ontology (GO) analysis for potato-specific miRNAs was also performed to predict their potential biological functions. Conclusions: We report a comprehensive study of potato miRNAs at genome-wide level by high-throughput sequencing and demonstrate that these miRNAs have tissue and/or developmental stage specific expression profile. Also, predicted targets of conserved miRNAs were experimentally confirmed for the first time in potato. Our findings indicate the existence of extensive and complex small RNA population in this crop and suggest their important role in pathways involved in diverse biological processes, including tuber developmental process. Total seven (Leaf, Root, Stem, Potato Tuber stage 0(PT0),Potato Tuber stage 1(PT1),Potato Tuber stage 2(PT2),Potato Tuber stage 3(PT3) ) small RNA libraries were consctructed and sequenced by deep sequencing using Illumina GAIIx.