Project description:Wood maturation produces two distinct wood tissues: juvenile wood (JW) and mature wood (LW), which are the major cause of wood qaulity variation within a tree. We investigate transcriptome reorganization during wood maturation process in radiata pine using a newly developed 18k cDNA microarrays.
Project description:Seasonal wood development results in two distinct wood types: earlywood (EW) and latewood (LW), which is the major cause of wood qaulity variation. We investigate transcriptome reorganization during seasonal wood development in radiata pine using a newly developed 18k cDNA microarrays. Three sampling trees each at juvenile (5 yrs), transition (9 yrs) and mature (14 yrs) ages (based on the wood rings at breast height) were selected from a plantation forest of radiata pine at Bondo, NSW , Australia (35º 16' 44.04 S, 148º 26' 54.66 E). The sampling trees at juvenile and mature ages were grown within 50 m distance and under similar environment. Two sampling trees at rotation age (30 yrs) were chosen at Yarralumla, ACT, Australia (35° 18' 27'' S, 149° 7' 27.9'' E).
Project description:Wood maturation produces two distinct wood tissues: juvenile wood (JW) and mature wood (LW), which are the major cause of wood qaulity variation within a tree. We investigate transcriptome reorganization during wood maturation process in radiata pine using a newly developed 18k cDNA microarrays. Developing xylem tissues from nine sampled trees at 5- and 13-year-old each were randomly divided into three groups with three trees each. Total RNA samples extracted from three trees within a group were pooled at equal amount before using for microarray experiments. Using this pooling strategy three biological replicates were formed for each microarray experiment. Dye swap was applied in each biological replicate. Comparisons between JW and MW in spring (EW) and autumn (LW) were arranged in two separate microarray experiments: juvenile earlywood (JE) vs. mature earlywood (ME), juvenile latewood (JL) vs. mature latewood (ML)
Project description:Seasonal wood development results in two distinct wood types: earlywood (EW) and latewood (LW), which is the major cause of wood qaulity variation. We investigate transcriptome reorganization during seasonal wood development in radiata pine using a newly developed 18k cDNA microarrays.
Project description:Wood density is a foundamental quality trait for structural timber, bioenergy and pulp industries. We investigated genes differentially transcribed in radiate pine juvneile trees with distinct wood density using cDNA microarrays. Radiata pine trees were selected from a progeny trial planted at Flynn, Australia. Based on the gravitical measurement of wood cores, 12 families with highest and lowest density each were selected, representing two groups of trees with contrasting wood density. One individual with higher or lower density were further sampled in each selected family. Developing xylem tissues of selected trees were sampled in autumn (April) when latewood (LW) was formed. The xylem tissues were scraped at breast height with a sharp chisel after the bark was removed. Wood cores of the sampled trees were further measured using SilviScan 2. Total RNA extracted from ten developing xylem tissues with confirmed distinct density in each tree group were pooled into two bulks (five trees each), and the two bulks of HD were compared with two LD bulks in the microarray experiment (named the bulk experiment). Six developing xylem tissues with the most distinct density from each tree group were further chosen. Six xylem tissues with HD were individually compared with bulked six xylem tissues with LD in the second microarray experiment (named individual experiment). These two different pooling strategies can partly minimize the genetic variation among different genotypes. Dye swaps were applied in each biological replicate.
Project description:Wood density is a foundamental quality trait for structural timber, bioenergy and pulp industries. We investigated genes differentially transcribed in radiate pine juvneile trees with distinct wood density using cDNA microarrays.
Project description:Comparison of transcriptomes from bark, developing xylem and xylem of P. radiata saplings exposed to 0 or 1mg of Ethephon in lanolin for 1 or 8 weeks We developed an oligonucleotide microarray using sequences (mostly from Pinus taeda) from public sequence databases. These sequences were reconstituted into a non-redundant database by CAP3 assembly and used as templates for automated design of 60-mer oligonucleotide probes through eArray, Agilent’s online facility. The microarray slides, manufactured by Agilent, were used to monitor gene expression in an Ethephon-induction experiment. Ethephon was dispersed in lanolin paste and applied in a 3 cm band near the base of the stem of 2-year old Pinus radiata saplings. RNA was extracted from bark, cambial region, also known as “developing xylem”, and xylem tissues exposed for 1 or 8 weeks to Ethephon. The transcriptomes from these extracts were compared by hybridization onto the All-Pinus microarray slides. Statistically significant differentially expressed genes identified by limma (Linear Models for Microarray Data) were subsequently analysed by singular enrichment analysis through the Database for Annotation, Visualization and Integrated Discovery (DAVID) portal. Results revealed that bark, cambial region and xylem generate mostly mutually exclusive cohorts of genes and Gene Ontology (GO) classes. Ethephon induction led to the upregulation of xylem genes related to the metabolism of phenylpropanoids and flavonoids and to defence responses, specifically, fungal/insect attack and oxidative stress. Independent validation of the microarray data for five genes was obtained by quantitative RT-PCR. The results are also interpreted in reference to gross and microscopic morphological changes. These results confirm the utility of the All-Pinus microarray for transcriptomic research in P. radiata.