Small dosages of white light and blue light are sufficient for inhibition of sclerotial development while yellow, red and far-red light promote the formation of sclerotia. The development of apothecia also requires light as in the close relative Sclerotinia sclerotiorum in which normal apothecial development is strictly dependent on near-UV light or daylight as other qualities of light result in misshaped apothecia. Light strongly affects asexual and/or sexual development also in several other fungal species. A regulatory protein linking light signals with development and secondary metabolism was firstly identified in Aspergillus nidulans: DveA mutants showed light-independent conidiation, loss of fruiting body formation, and reduced production of secondary metabolites such as penicillin and sterigmatocystin. Further studies revealed that VeA acts as a bridging factor in a heteromeric protein complex that furthermore includes two other members of the VELVET protein family, the putative histone methyltransferase LaeA, the red lightsensing phytochrome FphA, and the blue light-responding GATA transcription factors LreA/LreB. Functional characterization of VeA homologues in Aspergillus parasiticus, Aspergillus fumigatus, Fusarium verticillioides, Aspergillus flavus, Acremonium chrysogenum, Neurospora crassa, Fusarium fujikuroi, Penicillium chrysogenum, Trichoderma virens, Mycosphaerella graminicola, Fusarium graminearum, Dothistroma septosporum, Cochliobolus heterostrophus, and Histoplasma capsulatum, confirmed the universal role of VELVET as a global regulator of development and secondary metabolism in ascomycetes. B. cinerea field populations are known for high genetic variation regarding their aggressiveness on different plant species, their spectra of produced phytotoxins, their resistance to fungicides, and their preferred mode of reproduction. Thus, field populations represent natural collections of genotypes and phenotypes that arise by random mutations resulting in single-nucleotide polymorphisms or even in chromosome rearrangements. The aim of this study was the elucidation of the genetic basis for phenotypic differences with regard to virulence, oxalic acid production and light-dependent differentiation between the two sequenced B. cinerea isolates: the aggressive and sclerotia-forming isolate B05.10 and the less aggressive, non-sclerotia-forming isolate T4. We pursued a map-based cloning approach using the progeny of a cross between strain T4 and a strain that was phenotypically identical with B05.10. The analysis of the progeny provided evidence that these three markers are genetically linked and revealed the VELVET gene bcvel1 as candidate for the gene locus responsible for the observed phenotypic differences. Deletion and complementation analyses confirmed the role of BcVEL1 in light-dependent differentiation, OA formation and virulence. Functional SJN 2511 enrichment analyses for the differentially expressed genes were performed using the GOEAST tool. These analyses revealed that the group of under-expressed genes is enriched with those involved in proteolytic processes. The large group of over-expressed genes is enriched with those involved in transmembrane transport and carbohydrate modification. Thus, several over-expressed genes encode putative MFS sugar transporter, amino acid transporter, MFS multidrug transporter and glycoside hydrolases. Notably, all three genes involved in nitrate metabolism are over-expressed in the deletion mutant.

Because different classes of secondary metabolites possess individual biological functions, it is reasonable to speculate that diverse secondary metabolites in rapeseed accumulate separately in specific tissues and play different roles in physiological processes or ecological interactions. A recent study, in which laser microdissection was successfully used to harvest specific tissues from CUDC-907 developing rapeseed, encouraged us to apply LMD to sample different tissues of mature rapeseed and map the distribution of diverse secondary metabolites in the seed tissues. Insights gained from understanding how secondary metabolites are distributed in rapeseed can help us to conceive the biosynthesis and function of these metabolites in the plant. LMD has been successfully used to harvest specific tissues or cells from plant material for transcript and protein analyses, and micro-spatial metabolic profiling studies. In this study, LMD was used to sample four different parts, namely, hypocotyl and radicle, inner cotyledon, outer cotyledon, seed coat and endosperm from mature rapeseed. Secondary metabolites of different classes found in rapeseed cv. Emerald, namely glucosinolates, sinapine tissues by high-performance liquid chromatography – diode array detection and mass spectrometry. Here we report the distribution patterns of the above secondary metabolites in different rapeseed tissues and discuss their potential physiological and ecological relevance. Numerous studies have linked E2F activity to cell cycle control. These studies have delineated roles for individual E2Fs in regulating G1/S and G2/M phase transitions of the cell cycle through activation and repression of target genes. The E2F family is comprised of eight distinct gene products which can be divided into three subclasses based on shared functional properties and sequence homologies. E2F1, E2F2 and E2F3 function as activators of transcription and make up one subset. These activator E2Fs are tightly regulated with essentially no expression in quiescent cells and are dramatically induced as cells are stimulated to grow. During mid-to-late G1 phase of cell cycle progression, many E2F-responsive promoters are bound by E2F1, E2F2 or E2F3 coincident with gene activation. E2F4 and E2F5 comprise the second subset of E2F family members. In contrast to the activating E2Fs, E2F4 and E2F5 lack an activation domain and function as repressors of transcription. In the cell cycle, E2F4 and E2F5 are mainly involved in the repression of growth promoting E2F-responsive genes. Studies to elucidate the mechanism of E2F action revealed that these transcription factors modulate gene expression through the formation of coactivator or corepressor complexes that alter chromatin. E2Fs1-3, for example, have been documented to recruit p300/CBP and PCAF/GCN5 histone acetyltransferases to activate target promoters while E2F4 promoter occupancy has been linked to the Sin3B corepressor/ HDAC complex. E2F6, E2F7 and E2F8 comprise the third and most recently discovered group of E2Fs. These E2Fs are unique in that they lack the activation domain common to E2Fs1-3 and the RB-binding domain common to all other E2Fs. Among this third group of E2Fs, the function of E2F6 has perhaps been the most investigated. Mouse knockout studies show E2f6-null mice are healthy and viable but display homeotic transformation of the axial skeleton suggesting a role for E2F6 in developmental patterning.

Interestingly, we did not detect altered proliferation in Tgfb3-deficient keratinocytes and wild type keratinocytes grown in the presence of NAB, as well as in the basal layer of embryonic skin, suggesting that the proliferation defect in injured skin may be unique to a condition of tissue repair. Furthermore, it supports a role for a TGF-ß3- dependent paracrine effect on keratinocytes, mediated by cells from the granulation tissue. Recent reports have identified a TGFßR2-Smad-independent TGF-ß3 signaling in palatogenesis. This non-canonical pathway utilizes the MAPK signaling, known to regulate the production of numerous downstream targets, including interleukin 6, a well-known critical regulator of keratinocyte migration. TGF-ß3 is probably best-known for its antiscarring effect, and recombinant TGF-ß3 has been used in clinical trials as prophylactic treatment of human scars. TGF- ß3-injected wounds exhibit decreased expression of a-smooth muscle actin in the granulation tissue, consistent with an antiscarring effect. However, the collagen fiber network was unchanged. Interestingly, despite the low level of a-smooth muscle actin, TGF-ß3-injected wounds show the same wound volume compared to controls, suggesting that perhaps a-smooth muscle actin expression is more related to granulation tissue remodeling and myofibroblast differentiation than tissue contraction. The absence of TGF-ß3, however, leads to larger and deeper wounds. When stained for asmooth muscle actin, however, wounds injected with TGF-ß3 neutralizing antibody show very small areas with a-smooth muscle actin positive myofibroblasts at 7 and 11 days post-wounding. Furthermore, collagen fiber network was not fully mature. These results would suggest that TGF-ß3 is required for fibroblast/ myofibroblast transdifferentiation and proper granulation tissue maturation in the wound area and are consistent with the effect of the injection of a viral construct containing a mutant TGF-ß3 into cutaneous wounds. Both studies would be consistent with a mathematical model that predicts an increase in wound size after early elimination of TGF-ß. Several reports describe the expression of TGF-ß3 in tissues and cells throughout development and during adulthood, yet not consistently in the same tissues and cells. We took advantage of a new allele with Cre recombinase knocked in the TGF-ß3 locus to determine spatial and temporal expression of Tgfb3 during cutaneous wound healing. X-gal staining indicated the presence of positive signal in the suprabasal layers of the epidermis and hair follicle cells in wounded and unwounded tissues. Although the staining reflects the transformation of cells that have expressed or continue to transcribe from the TGF-ß3 promoter, its pattern in the epidermis and hair follicle is similar to the expression of Cre-recombinase shown previously. These observations only partially mirror previous studies that indicated the presence of Tgfb3 throughout the epidermis, in the granulation tissue and in mesenchymal derivatives. Differences in animal models and method of detection could be at the origin of these discrepancies. In summary, our study indicates the requirement of an adequate level of TGF-ß3 for proper wound healing. TGF-ß3 is also critical for embryonic development, as Tgfb3-deficient mice exhibit cleft palate. It is INCB28060 therefore tempting to postulate that TGF-ß3 is part of a global pathway that is essential for both adult wound repair and embryonic tissue development.