Project description:Currently little is known about the genetic mechanisms regulating the vascular cambium or the secondary growth of stems. We show here that the Populus Class I KNOX homeobox gene ARBORKNOX2 (ARK2) regulates both cell division in the cambium region and the differentiation of daughter cells in secondary xylem and phloem. ARK2 is expressed in the shoot apical meristem, and the vascular cambium region, reflecting some overlap in the regulation of these meristems. ARK2 is expressed broadly in the cambium region and in differentiating lignified cells types before becoming progressively restricted to the cambium. Populus overexpressing ARK2 present stem phenotypes with precocious cambium formation, delayed differentiation of cambium daughter cells, a wider cambium region, and ultimately less phloem fibers and secondary xylem. In contrast, Populus expressing RNAi or amicroRNA that target ARK2 transcripts present precocious differentiation of secondary phloem fibers and xylem, and ultimately more secondary xylem tissue and thicker secondary cell walls in phloem fibers and secondary xylem cells. These phenotypes in turn correlate with changes in the expression of genes affecting cell division, auxin, and cell wall synthesis and lignification that indicate that ARK2 primarily affects woody tissue development by regulation of cell differentiation. Notably, wood properties associated with secondary cell wall synthesis are negatively associated with ARK2 expression, including lignin and cellulose content. Together, our results suggest that ARK2 functions primarily by negatively regulating cell differentiation during secondary growth. We propose that ARK2 may identify a co-evolved regulatory module that influences complex wood properties relevant to ecological, industrial, and biofuels applications.
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.
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 6 dye-swap - time course
Project description:We take the two year old plant for sampling.Use the Affymetrix poplar gene chip to elucidate the gene functions and mechanisms in Populus tomentosa shoot apex and mature xylem. We used microarrays to detail the global programme of gene expression in shoot apex and mature xylem.
Project description:We applied RNA-seq to 3-month-old rice (Oryza sativa) shoot apical meristem to investigate the effect of RGA1(d1-1) mutation on the meristem initiation using transcriptome of d1 as compared to wild type plant.
Project description:We take the two year old plant for sampling.Use the Affymetrix poplar gene chip to elucidate the gene functions and mechanisms in Populus tomentosa shoot apex and mature xylem. We used microarrays to detail the global programme of gene expression in shoot apex and mature xylem. Populus tomentosa shoot apex and mature xylem were taken for RNA extraction and hybridization on Affymetrix microarrays.CB2009304-C and CB2009304-D from shoot apex, CB2009304-G and CB2009304-H from mature xylem.
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:We investigated the chromatin modifications H3K4me3 and H3K27me3 in the A. thaliana shoot apical meristem using INTACT reporter lines. Samples were collected in two biological replications.
