Overexpression of REDUCED WALL ACETYLATION C increases xylan acetylation and biomass recalcitrance in Populus.

Plant lignocellulosic biomass, i.e. secondary cell walls of plants, is a vital alternative source for bioenergy.

PdWND3A, a wood-associated NAC domain-containing protein, affects lignin biosynthesis and composition in Populus.

Background: Plant secondary cell wall is a renewable feedstock for biofuels and biomaterials production. Arabidopsis VASCULAR-RELATED NAC DOMAIN (VND) has been demonstrated to be a key transcription factor regulating secondary cell wall biosynthesis. However, less is known about its role in the woody species.

Overexpression of a Prefoldin β subunit gene reduces biomass recalcitrance in the bioenergy crop Populus.

Prefoldin (PFD) is a group II chaperonin that is ubiquitously present in the eukaryotic kingdom. Six subunits (PFD1-6) form a jellyfish-like heterohexameric PFD complex and function in protein folding and cytoskeleton organization. However, little is known about its function in plant cell wall-related processes.

A New Calmodulin-Binding Protein Expresses in the Context of Secondary Cell Wall Biosynthesis and Impacts Biomass Properties in .

A greater understanding of biosynthesis, signaling and regulatory pathways involved in determining stem growth and secondary cell wall chemistry is important for enabling pathway engineering and genetic optimization of biomass properties. The present study describes a new functional role of , a gene belonging to the IQ67-Domain1 family of genes, in impacting biomass formation and chemistry. Expression studies showed that has enhanced expression in developing xylem and tension-stressed tissues in .

Overexpression of a Domain of Unknown Function 266-containing protein results in high cellulose content, reduced recalcitrance, and enhanced plant growth in the bioenergy crop .

Background: Domain of Unknown Function 266 (DUF266) is a plant-specific domain. DUF266-containing proteins (DUF266 proteins) have been categorized as 'not classified glycosyltransferases (GTnc)' due to amino acid similarity with GTs. However, little is known about the function of DUF266 proteins.

Down-regulation of p-coumaroyl quinate/shikimate 3'-hydroxylase (C3'H) and cinnamate 4-hydroxylase (C4H) genes in the lignin biosynthetic pathway of Eucalyptus urophylla × E. grandis leads to improved sugar release.

Background: Lignocellulosic materials provide an attractive replacement for food-based crops used to produce ethanol. Understanding the interactions within the cell wall is vital to overcome the highly recalcitrant nature of biomass. One factor imparting plant cell wall recalcitrance is lignin, which can be manipulated by making changes in the lignin biosynthetic pathway.

Transgenic American chestnuts show enhanced blight resistance and transmit the trait to T1 progeny.

American chestnut (Castanea dentata) is a classic example of a native keystone species that was nearly eradicated by an introduced fungal pathogen. This report describes progress made toward producing a fully American chestnut tree with enhanced resistance to the blight fungus (Cryphonectria parasitica). The transgenic American chestnut 'Darling4,' produced through an Agrobacterium co-transformation procedure to express a wheat oxalate oxidase gene driven by the VspB vascular promoter, shows enhanced blight resistance at a level intermediate between susceptible American chestnut and resistant Chinese chestnut (Castanea mollissima).

Control of pollen-mediated gene flow in transgenic trees.

Pollen elimination provides an effective containment method to reduce direct gene flow from transgenic trees to their wild relatives. Until now, only limited success has been achieved in controlling pollen production in trees. A pine (Pinus radiata) male cone-specific promoter, PrMC2, was used to drive modified barnase coding sequences (barnaseH102E, barnaseK27A, and barnaseE73G) in order to determine their effectiveness in pollen ablation.

Short-rotation woody crops for bioenergy and biofuels applications.

Purpose-grown trees will be part of the bioenergy solution in the United States, especially in the Southeast where plantation forestry is prevalent and economically important. Trees provide a "living biomass inventory" with existing end-use markets and associated infrastructure, unlike other biomass species such as perennial grasses. The economic feasibility of utilizing tree biomass is improved by increasing productivity through alternative silvicultural systems, improved breeding and biotechnology.

Structure and expression of duplicate AGAMOUS orthologues in poplar.

To investigate the homeotic systems underlying floral development in a dioecious tree, and to provide tools for the manipulation of floral development, we have isolated two Populus trichocarpa genes, PTAG1 and PTAG2, homologous to the Arabidopsis floral homeotic gene AGAMOUS (AG). PTAG1 and PTAG2 are located on separate linkage groups, but their non-coding regions are highly similar, consistent with a phylogenetically recent duplication. Intron/exon structure is conserved in relation to AG and the Antirrhinum AG orthologue, PLENA (PLE), and low-stringency Southern analysis demonstrated the absence of additional genes in the poplar genome with significant PTAG1/2 homology.

A DEFICIENS homolog from the dioecious tree black cottonwood is expressed in female and male floral meristems of the two-whorled, unisexual flowers.

We isolated PTD, a member of the DEFICIENS (DEF) family of MADS box transcription factors, from the dioecious tree, black cottonwood (Populus trichocarpa). In females, in situ hybridization experiments showed that PTD mRNA was first detectable in cells on the flanks of the inflorescence meristem, before differentiation of individual flowers was visually detectable. In males, the onset of PTD expression was delayed until after individual flower differentiation had begun and floral meristems were developing.

Diverse effects of overexpression of LEAFY and PTLF, a poplar (Populus) homolog of LEAFY/FLORICAULA, in transgenic poplar and Arabidopsis.

PTLF, the Populus trichocarpa homolog of LEAFY (LFY) and FLORICAULA, was cloned to assess its function in a dioecious tree species. In situ hybridization studies showed that the gene was expressed most strongly in developing inflorescences. Expression was also seen in leaf primordia and very young leaves, most notably in apical vegetative buds near inflorescences, but also in seedlings.

A mutation hotspot in the chloroplast genome of a conifer (Douglas-fir: Pseudotsuga) is caused by variability in the number of direct repeats derived from a partially duplicated tRNA gene.

We determined the DNA sequence of a 2.7-kb cpDNA XbaI fragment from douglas-fir [Pseudotsuga menziesii (Mirb.) Franco].

LE-ACS4, a fruit ripening and wound-induced 1-aminocyclopropane-1-carboxylate synthase gene of tomato (Lycopersicon esculentum). Expression in Escherichia coli, structural characterization, expression characteristics, and phylogenetic analysis.

ACC (1-aminocyclopropane-1-carboxylic acid) synthase is the key regulatory enzyme in the biosynthetic pathway of the plant hormone ethylene and is encoded by a highly divergent multigene family in tomato (Rottmann, W. H., Peter, G.

Use of a tomato mutant constructed with reverse genetics to study fruit ripening, a complex developmental process.

Fruit ripening is one of the most dramatic developmental transitions associated with extensive alteration in gene expression. The plant hormone ethylene is considered to be the causative ripening agent. Transgenic tomato plants were constructed expressing antisense or sense RNA to the key enzyme in the ethylene (C2H4) biosynthetic pathway, 1-aminocyclopropane-1-carboxylate (ACC) synthase using the constitutive CaMV 35S and fruit specific E8 promoters.

1-aminocyclopropane-1-carboxylate synthase in tomato is encoded by a multigene family whose transcription is induced during fruit and floral senescence.

The key regulatory enzyme in the biosynthetic pathway of the plant hormone ethylene is 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (EC 4.1.1.

Transfer of methomyl and HmT-toxin sensitivity from T-cytoplasm maize to tobacco.

The mitochondrial gene, T-urf13, which is unique to the T-cytoplasm of maize, has been expressed in tobacco plants using the Cauliflower Mosaic Virus 35S promoter. Tobacco plants expressing T-urf13 exhibit a variety of responses to methomyl. Leaf discs and petiole sections bleach when exposed to methomyl or HmT-toxin; this effect increases with the age of the tissue.

Two genes encoding 1-aminocyclopropane-1-carboxylate synthase in zucchini (Cucurbita pepo) are clustered and similar but differentially regulated.

A 17-kilobase (kb) region of the zucchini (Cucurbita pepo) genome has been sequenced and contains two genes, CP-ACC1A and CP-ACC1B, encoding 1-aminocyclopropane-1-carboxylate synthase (ACC synthase; S-adenosyl-L-methionine methylthioadenosine-lyase, EC 4.4.1.

A mitochondrial gene is lost via homologous recombination during reversion of CMS T maize to fertility.

The Texas (T) male sterile cytoplasm of maize is distinguished by a mitochondrially synthesized 13-kd polypeptide and a high susceptibility to the toxin produced by the fungal pathogen Helminthosporium maydis. Fertile, toxin-resistant revertants show an altered restriction profile for mitochondrial DNA and do not produce the 13-kd polypeptide. Characterization of cosmid clones from CMS T maize and a revertant shows that a heavily transcribed open reading frame named T-URF13, potentially coding a 13-kd product, is deleted in the revertant mitochondria.

The complete amino acid sequence of the human aldolase C isozyme derived from genomic clones.

The complete protein sequence of the human aldolase C isozyme has been determined from recombinant genomic clones. A genomic fragment of 6673 base pairs was isolated and the DNA sequence determined. Aldolase protein sequences, being highly conserved, allowed the derivation of the sequence of this isozyme by comparison of open reading frames in the genomic DNA to the protein sequence of other human aldolase enzymes.

Experimental mechanical and histologic evaluation of the Kennedy ligament augmentation device.

Reconstruction of the knee with a chronic injury to the anterior cruciate ligament is an unsolved problem. Biologic graft substitutes have failed to maintain knee stability in the longer postreconstruction intervals. In an attempt to overcome the limitations in graft performance, synthetic materials have been proposed to augment the biologic tissue.

Analysis of changes in a yolk glycoprotein complex in the developing sea urchin embryo.

A sea urchin yolk glycoprotein complex (YGC) was isolated from several developmental stages by velocity centrifugation on sucrose gradients. The YGCs were analyzed by SDS-polyacrylamide gel electrophoresis to determine if the molecular composition of the YGC was changing during development. The mass of the YGC did not change with development.

Complete amino acid sequence for human aldolase B derived from cDNA and genomic clones.

Several aldolase B clones from a human liver cDNA library have been identified by using a rabbit aldolase A cDNA as a hybridization probe. The most complete of these, pHL413, is 1389 base pairs long and covers approximately equal to 80% of the length of the mRNA, including 90% of the translated region. The cDNA, pHL413, was used to identify a genomic clone, lambda HG313, which encoded the remaining amino acids of human aldolase B.