Functional Analysis of the White Spruce Cellulose Synthase Gene Promoter in Secondary Xylem.

Cellulose is an essential structural component of the plant cell wall. Its biosynthesis involves genes encoding cellulose synthase enzymes and a complex transcriptional regulatory network. Three cellulose synthases have been identified in conifers as being potentially involved in secondary cell wall biosynthesis because of their preferential expression in xylem tissues; however, no direct functional association has been made to date.

Large-scale screening of transcription factor-promoter interactions in spruce reveals a transcriptional network involved in vascular development.

This research aimed to investigate the role of diverse transcription factors (TFs) and to delineate gene regulatory networks directly in conifers at a relatively high-throughput level. The approach integrated sequence analyses, transcript profiling, and development of a conifer-specific activation assay. Transcript accumulation profiles of 102 TFs and potential target genes were clustered to identify groups of coordinately expressed genes.

Opposite action of R2R3-MYBs from different subgroups on key genes of the shikimate and monolignol pathways in spruce.

Redundancy and competition between R2R3-MYB activators and repressors on common target genes has been proposed as a fine-tuning mechanism for the regulation of plant secondary metabolism. This hypothesis was tested in white spruce [Picea glauca (Moench) Voss] by investigating the effects of R2R3-MYBs from different subgroups on common targets from distinct metabolic pathways. Comparative analysis of transcript profiling data in spruces overexpressing R2R3-MYBs from loblolly pine (Pinus taeda L.

Habituation to thaxtomin A in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis.

Background: Thaxtomin A (TA), a phytotoxin produced by the phytopathogen Streptomyces scabies, is essential for the development of potato common scab disease. TA inhibits cellulose synthesis but its actual mode of action is unknown. Addition of TA to hybrid poplar (Populus trichocarpa x Populus deltoides) cell suspensions can activate a cellular program leading to cell death.

SABATH methyltransferases from white spruce (Picea glauca): gene cloning, functional characterization and structural analysis.

Known members of the plant SABATH family of methyltransferases have important biological functions by methylating hormones, signalling molecules and other metabolites. While all previously characterized SABATH genes were isolated from angiosperms, in this article, we report on the isolation and functional characterization of SABATH genes from white spruce (Picea glauca [Moench] Voss), a gymnosperm. Through EST database search, three genes that encode proteins significantly homologous to known SABATH proteins were identified from white spruce.

Transcriptional profiling in response to inhibition of cellulose synthesis by thaxtomin A and isoxaben in Arabidopsis thaliana suspension cells.

The plant cell wall determines cell shape and is the main barrier against environmental challenges. Perturbations in the cellulose content of the wall lead to global modifications in cellular homeostasis, as seen in cellulose synthase mutants or after inhibiting cellulose synthesis. In particular, application of inhibitors of cellulose synthesis such as thaxtomin A (TA) and isoxaben (IXB) initiates a programmed cell death (PCD) in Arabidopsis thaliana suspension cells that is dependent on de novo gene transcription.

Thaxtomin A induces programmed cell death in Arabidopsis thaliana suspension-cultured cells.

Thaxtomin A is the main phytotoxin produced by Streptomyces scabiei, the causative agent of common scab disease of potato. Pathogenicity of S. scabiei is dependent on the production of thaxtomin A which is required for the development of disease symptoms, such as growth inhibition and cell death.

Activity of a flax pectin methylesterase promoter in transgenic tobacco pollen.

The regulatory region of the flax Lupme3 gene, which codes for a pectin methylesterase, contains two sequences (PB box) that are putative cis-active sequence elements thought to regulate transcription in pollen. The Lupme3 promoter was fused to the beta-glucuronidase (gus) reporter gene. The chimeric gene fusion was introduced into tobacco via Agrobacterium-mediated transformation.