Transcriptomic Analysis Reveals Novel Regulators of the Scots Pine Stilbene Pathway.

Stilbenes accumulate in Scots pine heartwood where they have important roles in protecting wood from decaying fungi. They are also part of active defense responses, and their production is induced by different (a)biotic stressors. The specific transcriptional regulators as well as the enzyme responsible for activating the stilbene precursor cinnamate in the pathway are still unknown.

Petunia dihydroflavonol 4-reductase is only a few amino acids away from producing orange pelargonidin-based anthocyanins.

Anthocyanins are responsible for the color spectrum of both ornamental and natural flowers. However, not all plant species produce all colors. For example, roses are not blue because they do not naturally possess a hydroxylase that opens the pathway for delphinidin and its derivatives.

Regulation of PaRBOH1-mediated ROS production in Norway spruce by Ca binding and phosphorylation.

Plant respiratory burst oxidase homologs (RBOHs) are plasma membrane-localized NADPH oxidases that generate superoxide anion radicals, which then dismutate to HO, into the apoplast using cytoplasmic NADPH as an electron donor. is the most highly expressed gene in developing xylem as well as in a lignin-forming cell culture of Norway spruce ( L. Karst.

De novo transcriptome assembly of Conium maculatum L. to identify candidate genes for coniine biosynthesis.

Poison hemlock (Conium maculatum L.) is a notorious weed containing the potent alkaloid coniine. Only some of the enzymes in the coniine biosynthesis have so far been characterized.

Polyketide reductases in defense-related parasorboside biosynthesis in Gerbera hybrida share processing strategies with microbial polyketide synthase systems.

Plant polyketides are well-known for their crucial functions in plants and their importance in the context of human health. They are synthesized by type III polyketide synthases (PKSs) and their final functional diversity is determined by post-PKS tailoring enzymes. Gerbera hybrida is rich in two defense-related polyketides: gerberin and parasorboside.

Tetraketide α-pyrone reductases in sporopollenin synthesis pathway in Gerbera hybrida: diversification of the minor function.

The structurally robust biopolymer sporopollenin is the major constituent of the exine layer of pollen wall and plays a vital role in plant reproductive success. The sporopollenin precursors are synthesized through an ancient polyketide biosynthetic pathway consisting of a series of anther-specific enzymes that are widely present in all land plant lineages. Tetraketide α-pyrone reductase 1 (TKPR1) and TKPR2 are two reductases catalyzing the final reduction of the carbonyl group of the polyketide synthase-synthesized tetraketide intermediates to hydroxylated α-pyrone compounds, important precursors of sporopollenin.

Phyllotactic patterning of gerbera flower heads.

Phyllotaxis, the distribution of organs such as leaves and flowers on their support, is a key attribute of plant architecture. The geometric regularity of phyllotaxis has attracted multidisciplinary interest for centuries, resulting in an understanding of the patterns in the model plants and tomato down to the molecular level. Nevertheless, the iconic example of phyllotaxis, the arrangement of individual florets into spirals in the heads of the daisy family of plants (Asteraceae), has not been fully explained.

A transcriptomic view to wounding response in young Scots pine stems.

We studied the stress response of five-year-old Scots pine xylem to mechanical wounding using RNA sequencing. In general, we observed a bimodal response in pine xylem after wounding. Transcripts associated with water deficit stress, defence, and cell wall modification were induced at the earliest time point of three hours; at the same time, growth-related processes were down-regulated.

TCP and MADS-Box Transcription Factor Networks Regulate Heteromorphic Flower Type Identity in .

The large sunflower family, Asteraceae, is characterized by compressed, flower-like inflorescences that may bear phenotypically distinct flower types. The CYCLOIDEA (CYC)/TEOSINTE BRANCHED1-like transcription factors (TFs) belonging to the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) protein family are known to regulate bilateral symmetry in single flowers. In Asteraceae, they function at the inflorescence level, and were recruited to define differential flower type identities.

Hunting monolignol transporters: membrane proteomics and biochemical transport assays with membrane vesicles of Norway spruce.

Both the mechanisms of monolignol transport and the transported form of monolignols in developing xylem of trees are unknown. We tested the hypothesis of an active, plasma membrane-localized transport of monolignol monomers, dimers, and/or glucosidic forms with membrane vesicles prepared from developing xylem and lignin-forming tissue-cultured cells of Norway spruce (Picea abies L. Karst.

Isolation and Purity Assessment of Membranes from Norway Spruce.

Gaining membrane vesicles from different plant species and tissue types is crucial for membrane studies. Membrane vesicles can be used for further purification of individual membrane types, and, for example, in studies of membrane enzyme activities, transport assays, and in proteomic analysis. Membrane isolation from some species, such as conifers, has proved to be more difficult than that of angiosperm species.

Scandinavian perspectives on plant gene technology: applications, policies and progress.

Plant research and breeding has a long and successful history in the Scandinavian countries, Denmark, Finland, Norway and Sweden. Researchers in the region have been early in adopting plant gene technologies as they developed. This review gives a background, as well as discuss the current and future progress of plant gene technology in these four countries.

Dissecting functions of SEPALLATA-like MADS box genes in patterning of the pseudanthial inflorescence of Gerbera hybrida.

The pseudanthial inflorescences of the sunflower family, Asteraceae, mimic a solitary flower but are composed of multiple flowers. Our studies in Gerbera hybrida indicate functional diversification for SEPALLATA (SEP)-like MADS box genes that often function redundantly in other core eudicots. We conducted phylogenetic and expression analysis for eight SEP-like GERBERA REGULATOR OF CAPITULUM DEVELOPMENT (GRCD) genes, including previously unstudied gene family members.

Genetically engineered orange petunias on the market.

Unauthorized genetically engineered orange petunias were found on the market. Genetic engineering of petunia was shown to lead to novel flower color some 20 years ago. Here we show that petunia lines with orange flowers, generated for scientific purposes, apparently found their way to petunia breeding programmes, intentionally or unintentionally.

A Key Role for Apoplastic HO in Norway Spruce Phenolic Metabolism.

Apoplastic events such as monolignol oxidation and lignin polymerization are difficult to study in intact trees. To investigate the role of apoplastic hydrogen peroxide (HO) in gymnosperm phenolic metabolism, an extracellular lignin-forming cell culture of Norway spruce () was used as a research model. Scavenging of apoplastic HO by potassium iodide repressed lignin formation, in line with peroxidases activating monolignols for lignin polymerization.

Genome sequencing and population genomic analyses provide insights into the adaptive landscape of silver birch.

Silver birch (Betula pendula) is a pioneer boreal tree that can be induced to flower within 1 year. Its rapid life cycle, small (440-Mb) genome, and advanced germplasm resources make birch an attractive model for forest biotechnology. We assembled and chromosomally anchored the nuclear genome of an inbred B.

The O-methyltransferase PMT2 mediates methylation of pinosylvin in Scots pine.

Heartwood extractives are important determinants of the natural durability of pine heartwood. The most important phenolic compounds affecting durability are the stilbenes pinosylvin and its monomethylether, which in addition have important functions as phytoalexins in active defense. A substantial portion of the synthesized pinosylvin is 3-methoxylated but the O-methyltransferase responsible for this modification has not been correctly identified.

Functional characterization and expression of GASCL1 and GASCL2, two anther-specific chalcone synthase like enzymes from Gerbera hybrida.

The chalcone synthase superfamily consists of type III polyketidesynthases (PKSs), enzymes responsible for producing plant secondary metabolites with various biological and pharmacological activities. Anther-specific chalcone synthase-like enzymes (ASCLs) represent an ancient group of type III PKSs involved in the biosynthesis of sporopollenin, the main component of the exine layer of moss spores and mature pollen grains of seed plants. In the latter, ASCL proteins are localized in the tapetal cells of the anther where they participate in sporopollenin biosynthesis and exine formation within the locule.

Peroxidases Bound to the Growing Lignin Polymer Produce Natural Like Extracellular Lignin in a Cell Culture of Norway Spruce.

Lignin, an important component of plant cell walls, is a polymer of monolignols derived from the phenylpropanoid pathway. Monolignols are oxidized in the cell wall by oxidative enzymes (peroxidases and/or laccases) to radicals, which then couple with the growing lignin polymer. We have investigated the characteristics of the polymerization reaction by producing lignin polymers using different oxidative enzymes and analyzing the structures formed with NMR.

Developmental Changes in Scots Pine Transcriptome during Heartwood Formation.

Scots pine (Pinus sylvestris L.) wood is desired in woodworking industries due to its favorable timber characteristics and natural durability that is contributed by heartwood extractives. It has been discussed whether the Scots pine heartwood extractives (mainly stilbenes and resin acids) are synthesized in the cells of the transition zone between sapwood and heartwood, or if they are transported from the sapwood.

Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence.

The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences.

Two polyketide synthases are necessary for 4-hydroxy-5-methylcoumarin biosynthesis in Gerbera hybrida.

Gerbera (Gerbera hybrida) is an economically important ornamental species and a model plant of the Asteraceae family for flower development and secondary metabolism. Gerberin and parasorboside, two bitter tasting glucosidic lactones, are produced in high amounts in nearly all gerbera tissues. Gerbera and its close relatives also produce a rare coumarin, 4-hydroxy-5-methylcoumarin (HMC).