Project description:Plant growth is the result of cell proliferation in the meristems, which requires a dynamic balance between the formation of new tissue and the maintenance of a set of undifferentiated stem cells. There is much that remains unknown about this vital developmental process. In this study, we have reported the generation of 2735 ESTs from three cDNA libraries derived from dissected garden pea (Pisum sativum cv Torsdag) shoot apical meristems. Clustering analysis of the resulting sequences gave rise to 1686 non-redundant ESTs. The unique sequences generated together with 500 other pea transcripts randomly selected from the GenBank pea protein database have been utilized to construct a 2K oligonucleotide array. Using this pea array, we have obtained the transcript profiles of pea shoot apical meristems in comparison to non-apical-meristem tissues. A total of 181 or 174 transcripts were identified to be significantly up- or down-regulated in the pea shoot apical meristem, respectively. As expected, close to 61% of the transcripts down-regulated in the shoot apical mersitem are those retrieved from the public database, whereas sequences from the same source only made up 12% of the genes that were expressed at higher levels in SAMs. This revelation highlights the under-representation of transcripts from the meristmatic tissues in the current public protein database. Manual inspection of the list of up-regulated transcripts reveals the presence of sequences predicted to encode products associated with cell division and proliferation, epigenetic regulation, auxin-mediated responses and miRNA regulation. Similar genes have been implicated in the regulation of plant stem cell activity. Taken together, our EST collection as well as the microarray data provides useful starting points for more in depth analysis of the meristem function and maintenance. Keywords: shoot apical meristem transcript profiling
Project description:Pea (Pisum. sativum L.) is a traditional and important edible legume that can be sorted into grain pea and vegetable pea according to their harvested maturely or not. Vegetable pea by eating the fresh seed is becoming more and more popular in recent years. These two type peas display huge variations of the taste and nutrition, but how seed development and nutrition accumulation of grain pea and vegetable pea and their differences at the molecular level remains poorly understood. To understand the genes and gene networks regulate seed development in grain pea and vegetable pea, high throughput RNA-Seq and bioinformatics analysis were used to compare the transcriptomes of vegetable pea and grain pea developing seed. RNA-Seq generated 18.7 G raw data, which was then de novo assembled into 77,273 unigenes with a mean length of 930 bp. Functional annotation of the unigenes was carried out using the nr, Swiss-Prot, COG, GO and KEGG databases. There were 459 and 801 genes showing differentially expressed between vegetable pea and grain pea at early and late seed maturation phases, respectively. Sugar and starch metabolism related genes were dramatically activated during pea seed development. The up-regulated of starch biosynthesis genes could explain the increment of starch content in grain pea then vegetable pea; while up-regulation of sugar metabolism related genes in vegetable pea then grain pea should participate in sugar accumulation and associated with the increase in sweetness of vegetable pea then grain pea. Furthermore, transcription factors were implicated in the seed development regulation in grain pea and vegetable pea. Thus, our results constitute a foundation in support of future efforts for understanding the underlying mechanism that control pea seed development and also serve as a valuable resource for improved pea breeding.
Project description:Plant growth is the result of cell proliferation in the meristems, which requires a dynamic balance between the formation of new tissue and the maintenance of a set of undifferentiated stem cells. There is much that remains unknown about this vital developmental process. In this study, we have reported the generation of 2735 ESTs from three cDNA libraries derived from dissected garden pea (Pisum sativum cv Torsdag) shoot apical meristems. Clustering analysis of the resulting sequences gave rise to 1686 non-redundant ESTs. The unique sequences generated together with 500 other pea transcripts randomly selected from the GenBank pea protein database have been utilized to construct a 2K oligonucleotide array. Using this pea array, we have obtained the transcript profiles of pea shoot apical meristems in comparison to non-apical-meristem tissues. A total of 181 or 174 transcripts were identified to be significantly up- or down-regulated in the pea shoot apical meristem, respectively. As expected, close to 61% of the transcripts down-regulated in the shoot apical mersitem are those retrieved from the public database, whereas sequences from the same source only made up 12% of the genes that were expressed at higher levels in SAMs. This revelation highlights the under-representation of transcripts from the meristmatic tissues in the current public protein database. Manual inspection of the list of up-regulated transcripts reveals the presence of sequences predicted to encode products associated with cell division and proliferation, epigenetic regulation, auxin-mediated responses and miRNA regulation. Similar genes have been implicated in the regulation of plant stem cell activity. Taken together, our EST collection as well as the microarray data provides useful starting points for more in depth analysis of the meristem function and maintenance. Keywords: shoot apical meristem transcript profiling Total RNA was extracted from dissected SAM (approximately 80 SAMs per extraction) or other plant parts (primary stem, primary roots and mature leaves) using Qiagen RNeasy Mini Kit. Four independent tissue collections and RNA extractions (designated A, B, C and D) were performed for each of the microarray hybridization experiment.The Cy5- or Cy3-labelled cDNA was then hybridized to different sector of the chip according to a balanced block design dual label experiment scheme (Cochran & Cox, 1992): Sector 1: Cy3-SAM A vs Cy5-NM A Sector 2: Cy5-SAM B vs Cy3-NM B Sector 3: Cy3-SAM C vs Cy5-NM C Sector 4: Cy5-SAM D vs Cy3-NM D
Project description:au10-15_cineroots - transdifferentiation - Study of the molecular mechanism during transdifferenciation from root apical meristem to shoot apical meristem - culture in middle with different hormons, permits transdifferenciation from root to shoot tissues.
Project description:gnp07_regeneome_transdifferenciation - microdissection - Study of the moleculars mecanism during transdifferenciation of Root ApicalMeristem to Shoot Apical Meristem - middle of growth permits to induce transdifferenciation of root apical meristem to shoot apical meristem
Project description:au10-15_cineroots - transdifferentiation - Study of the molecular mechanism during transdifferenciation from root apical meristem to shoot apical meristem - culture in middle with different hormons, permits transdifferenciation from root to shoot tissues. 6 dye-swap - time course
Project description:Knowledge about an organism’s cell and tissue-specific transcriptional repertoire is essential for understanding the gene regulatory circuits that control key developmental events. The shoot apical meristem (SAM) is responsible for development of all the above ground parts of plants. Our understanding of SAM at the molecular level is far from complete. The present work investigates the global gene expression repertoire of SAMs in the garden pea (Pisum sativum). To this end, 10,346 EST sequences representing 7611 unique genes were generated from pea SAM cDNA libraries. These sequences, together with previously reported ESTs, were used to construct a 12K oligonucleotide array used to identify genes exhibiting differential SAM expression, as compared to the axillary meristem, root apical meristem, and non-meristematic tissues. We identified a number of genes that are predominantly expressed in specific cell layers or domains of the SAM, and thus are likely components of the gene networks involved in stem cell maintenance and initiation of lateral organ primordial cells. In situ hybridization confirmed the spatial localisation of some of these key genes within the SAM. Our data also indicate the diversification of some gene expression patterns and functions in legume crop plants.