Differentiation and secondary metabolism are correlated processes in fungi that respond to light. In
Aspergillus nidulans
, light inhibits sexual reproduction as well as secondary metabolism. We identified
the heterotrimeric
velvet
complex VelB/VeA/LaeA connecting light-responding developmental
regulation and control of secondary metabolism. VeA, which is primarily expressed in the dark,
physically interacts with VelB, which is expressed during sexual development. VeA bridges VelB to the
nuclear master regulator of secondary metabolism, LaeA. Deletion of either
velB
or
veA
results in
defects in both sexual fruiting-body formation and the production of secondary metabolites.

VelB/VeA/LaeA Complex CoordinatesLight Signal with Fungal Developmentand Secondary Metabolism

Plants in their natural habitat have to face multiple stresses simultaneously. Evolutionary adaptation of developmental, physiological, and biochemical parameters give advantage over a single window of stress but not multiple. On the other hand transcription factors like WRKY can regulate diverse responses through a complicated network of genes. So molecular orchestration of WRKYs in plant may provide the most anticipated outcome of simultaneous multiple responses. Activation or repression through W-box and W-box like sequences is regulated at transcriptional, translational, and domain level. Because of the tight regulation involved in specific recognition and binding of WRKYs to downstream promoters, they have become promising candidate for crop improvement. Epigenetic, retrograde and proteasome mediated regulation enable WRKYs to attain the dynamic cellular homeostatic reprograming. Overexpression of several WRKYs face the paradox of having several beneficial affects but with some unwanted traits. These overexpression-associated undesirable phenotypes need to be identified and removed for proper growth, development and yeild. Taken together, we have highlighted the diverse regulation and multiple stress response of WRKYs in plants along with the future prospects in this field of research.

/pdf/wrky-transcription-factors-molecular-regulation-and-stress-2cpccsr1cr.pdf

WRKY Transcription Factors: Molecular Regulation and Stress Responses in Plants.

SUMMARY Basidiomycete fungi subsist on various types of plant material in diverse environments, from living and dead trees and forest litter to crops and grasses and to decaying plant matter in soils. Due to the variation in their natural carbon sources, basidiomycetes have highly varied plant-polysaccharide-degrading capabilities. This topic is not as well studied for basidiomycetes as for ascomycete fungi, which are the main sources of knowledge on fungal plant polysaccharide degradation. Research on plant-biomass-decaying fungi has focused on isolating enzymes for current and future applications, such as for the production of fuels, the food industry, and waste treatment. More recently, genomic studies of basidiomycete fungi have provided a profound view of the plant-biomass-degrading potential of wood-rotting, litter-decomposing, plant-pathogenic, and ectomycorrhizal (ECM) basidiomycetes. This review summarizes the current knowledge on plant polysaccharide depolymerization by basidiomycete species from diverse habitats. In addition, these data are compared to those for the most broadly studied ascomycete genus, Aspergillus, to provide insight into specific features of basidiomycetes with respect to plant polysaccharide degradation.

Plant-Polysaccharide-Degrading Enzymes from Basidiomycetes

We present a phylogenetic and phylogenomic overview of the Polyporales. The newly sequenced genomes of Bjerkandera adusta, Ganoderma sp., and Phlebia brevispora are introduced and an overview of 10 currently available Polyporales genomes is provided. The new genomes are 39 500 000-49 900 00 bp and encode for 12 910-16 170 genes. We searched available genomes for single-copy genes and performed phylogenetic informativeness analyses to evaluate their potential for phylogenetic systematics of the Polyporales. Phylogenomic datasets (25, 71, 356 genes) were assembled for the 10 Polyporales species with genome data and compared with the most comprehensive dataset of Polyporales to date (six-gene dataset for 373 taxa, including taxa with missing data). Maximum likelihood and Bayesian phylogenetic analyses of genomic datasets yielded identical topologies, and the corresponding clades also were recovered in the 373-taxa dataset although with different support values in some datasets. Three previously recognized lineages of Polyporales, antrodia, core polyporoid and phlebioid clades, are supported in most datasets, while the status of the residual polyporoid clade remains uncertain and certain taxa (e.g. Gelatoporia, Grifola, Tyromyces) apparently do not belong to any of the major lineages of Polyporales. The most promising candidate single-copy genes are presented, and nodes in the Polyporales phylogeny critical for the suprageneric taxonomy of the order are identified and discussed.

Phylogenetic and phylogenomic overview of the Polyporales

Volatile evolution of long noncoding RNA repertoires: mechanisms and biological implications.

Ganoderma lucidum is a widely used medicinal macrofungus in traditional Chinese medicine that creates a diverse set of bioactive compounds. Here we report its 43.3-Mb genome, encoding 16,113 predicted genes, obtained using next-generation sequencing and optical mapping approaches. The sequence analysis reveals an impressive array of genes encoding cytochrome P450s (CYPs), transporters and regulatory proteins that cooperate in secondary metabolism. The genome also encodes one of the richest sets of wood degradation enzymes among all of the sequenced basidiomycetes. In all, 24 physical CYP gene clusters are identified. Moreover, 78 CYP genes are coexpressed with lanosterol synthase, and 16 of these show high similarity to fungal CYPs that specifically hydroxylate testosterone, suggesting their possible roles in triterpenoid biosynthesis. The elucidation of the G. lucidum genome makes this organism a potential model system for the study of secondary metabolic pathways and their regulation in medicinal fungi. Ganoderma lucidumis a macrofungus in traditional Chinese medicine known to produce different bioactive compounds. In this study, the genome ofG. lucidumis sequenced, making this organism a potential model system for future studies of secondary metabolic pathways and their regulation in medicinal fungi.

/pdf/genome-sequence-of-the-model-medicinal-mushroom-ganoderma-2cylg1fonn.pdf

Genome sequence of the model medicinal mushroom Ganoderma lucidum

Transcription factors (TFs) are important regulating factors that can mediate many life processes. However, no TF genes have previously been reported in Panax quinquefolius (American ginseng), with the exception of a few expressed sequence tags. In this study, 753 unigenes (unique sequences) have been annotated in the plant transcription factor database PlnTFDB (version 3.0) by mining a 454 transcriptome dataset of P. quinquefolius. After classification of the unigenes, 45 unigenes were discovered to be annotated as WRKY transcripts in the public databases. Furthermore, PqWRKY1, one of the WRKY family TF genes that respond to methyl jasmonate, was isolated according to the sequences in the 454 transcriptome dataset. The cDNA of PqWRKY1 (P. quinquefolius WRKY1) encodes a putative protein of 358 amino acids, including a WRKY domain and a zinc finger motif. A subcellular localization assay demonstrated that the protein localizes to the nucleus and has strong transcriptional activation activity in transgenic yeast. In comparison to control lines, the PqWRKY1 transgenic Arabidopsis line exhibited insensitive phenotypes when exposed to high salt or mannitol. Correspondingly, in transgenic Arabidopsis lines, the expression levels of some genes involved in the anti-stress process were relatively higher than those in the control lines. Additionally, genes involved in triterpene biosynthesis were expressed onefold to fivefold higher in the transgenic line compared to the control line. These results suggest that the transcription factor PqWRKY1 is a positive regulator related to osmotic stress and triterpene ginsenoside biosynthesis in P. quinquefolius.

Discovery of WRKY transcription factors through transcriptome analysis and characterization of a novel methyl jasmonate-inducible PqWRKY1 gene from Panax quinquefolius

Mingzhu Liu

Papers

Genome sequence of the model medicinal mushroom Ganoderma lucidum

Discovery of WRKY transcription factors through transcriptome analysis and characterization of a novel methyl jasmonate-inducible PqWRKY1 gene from Panax quinquefolius