The Phenology of Synαnthedon myopαeformis Borkhausen (Lepidoptera: Sesiidae) in the Region of Larissa, Central Greece

Στη διάρκεια των ετών 1993, 1994, και 1995 μελετήθηκε η φαινολογία του ξυλοφάγου εντόμου Synanthedon myopaeformis Borkh. (Lepidoptera, Sesiidae) στη περιοχή της Αγιας Λάρισας όπου τα τελευταία χρόνια παρατηρείται έξαρση της προσβολής. Το μεγαλύτερο ποσοστό προσβολής παρατηρείται στις τομές κλάδευσης και στην περιοχή του εμβολίου. Τα αποτελε'σματα ε'δειξανότι το εντομο πιθανότατα συμπληρώνει στην περιοχή μια γενιά το χρόνο. Διαχειμάζει ως προνύμφη σε στοε'ς στο κορμό και στους χονδρούς βραχίονες. Η νύμφωση αρχίζει περί τα τέλη Μαρτίου με μέγιστο περί το τέλος Μαΐου με αρχές Ιουνίου. Οι πρώτες έξοδοι των ακμαίων παρατηρούνται το τελευταίο δεκαήμερο του Απριλίου, ένα μήνα περίπου μετά τις πρώτες νυμφώσεις, και το μέγιστοπερί τα μέσα Ιουνίου, 15 ημέρες περίπου μετά το μέγιστο των νυμφώσεων. Οι έξοδοι των ακμαίων κλιμακώνονται μέχρι το τέλος Οκτωβρίου αλλά τα 2/3 περίπου των εξόδων λαμβάνουν χώρα μέχρι τα μέσα Ιουλίου. Οι νεαρές προνύμφες της νέας γενιάς παρατηρούνται από αρχές Ιουνίου, με μέγιστο τέλος Ιουνίου - αρχές Ιουλίου. Η καταμέτρηση των νυμφικών εκδυμάτων είναιμια αξιόπιστη μέθοδος ελέγχου των εξόδων των ακμαίων στον οπο^ρώνα και παρέχει τη δυνατότητα σύγκρισης του ύψους της προσβολής ανάμεσα σε διαδοχικά χρόνια. Στον πειραματικό οπωρώνα παρατηρήθηκε μια σταθερή αύξηση της προσβολής από χρόνο σε χρόνο στη διάρκεια της μελέτης. Οι φερομονικές παγίδες είναι επίσης ένας δείκτης παρακολούθησης του ενηλίκου πληθυσμού στον οπωρώνα που όμως επηρεάζεται από διάφορους παράγοντες και οι οποίοι πρέπεινα λαμβάνονται υπόψη. Τα στοιχεία της μελέτης αυτής μπορούν να χρησιμεύσουν για τον άριστο χρόνο επέμβασης στη περιοχή ώστε ν' αποφευχθούν περιττοί ψεκασμοί.The phenology of Synanthedon myopaeformis Borkhausen. (Lepidoptera: Sesiidae) was studied in the region of Larissa, Central Greece, for three consecutive years (1993-1995). S. myopaeformis most propably completes one generation per year on apple trees. It overwinters as lavra of different sizes in the feeding tunnels in the trunk and branches. Pupation takes place from the end of March to the beginning of September with a peak in late May – beginning June. The emergence of adults takes place from late April to the beginning of October with the main peak in mid June. The larvae of the new generation start to appear from the beginning of May with a maximum in late June–beginning of July. Most of the infestation is observed in the grafting points and the pruning wounds. The results indicate that the pest becomes increasingly important in the study area. This study could be useful in determining the optimum timing of control measures

Grain number and grain weight as determinants of triticale, wheat, two-rowed and six-rowed barley yield in the Pannonian environment

Climate significantly affects cropping systems across Europe. Knowledge of the variability in grain number per unit area and grain weight across different growing seasons and its association with grain yield is important for further improving small grain crop production. The main aim of this study was to compare grain yield and its numerical components among triticale, wheat, two-rowed and six-rowed barley cultivars across different growing seasons in a typical Pannonian location (south-eastern part of Central Europe). Trials with twelve winter cereal genotypes (three two-rowed barley, three six-rowed barley, three wheat and three triticale genotypes) were carried out in four successive seasons in Novi Sad, Serbia. Results of this study showed that growing season, species, cultivar, and species x growing season interaction significantly (p lt 0.01) affected grain yield and its determinants. Generally, triticale had higher average grain yield, while the lowest grain yield was recorded in six-rowed barleys. Grain yield was more associated with the number of grains/m 2 than with grain weight. Heading date was recognized as one of the important adaptive traits in crop development and yield determination. Short duration of the pre-anthesis phase in early cultivars and delayed anthesis in late cultivars significantly decreased the number of grains/spike in different species/spike types, reducing the final grain yield. Medium early cultivars had the highest number of grains/spike due to optimal duration of the pre-anthesis period and heading date and are suggested as recommendable for large scale production in the Pannonian environments

Expression of the maize ZmGF14-6 gene in rice confers tolerance to drought stress while enhancing susceptibility to pathogen infection

14-3-3 proteins are found in all eukaryotes where they act as regulators of diverse signalling pathways associated with a wide range of biological processes. In this study the functional characterization of the ZmGF14-6 gene encoding a maize 14-3-3 protein is reported. Gene expression analyses indicated that ZmGF14-6 is up-regulated by fungal infection and salt treatment in maize plants, whereas its expression is down-regulated by drought stress. It is reported that rice plants constitutively expressing ZmGF14-6 displayed enhanced tolerance to drought stress which was accompanied by a stronger induction of drought-associated rice genes. However, rice plants expressing ZmGF14-6 either in a constitutive or under a pathogen-inducible regime showed a higher susceptibility to infection by the fungal pathogens Fusarium verticillioides and Magnaporthe oryzae. Under infection conditions, a lower intensity in the expression of defence-related genes occurred in ZmGF14-6 rice plants. These findings support that ZmGF14-6 positively regulates drought tolerance in transgenic rice while negatively modulating the plant defence response to pathogen infection. Transient expression assays of fluorescently labelled ZmGF14-6 protein in onion epidermal cells revealed a widespread distribution of ZmGF14-6 in the cytoplasm and nucleus. Additionally, colocalization experiments of fluorescently labelled ZmGF14-6 with organelle markers, in combination with cell labelling with the endocytic tracer FM4-64, revealed a subcellular localization of ZmGF14-6 in the early endosomes. Taken together, these results improve our understanding of the role of ZmGF14-6 in stress signalling pathways, while indicating that ZmGF14-6 inversely regulates the plant response to biotic and abiotic stresses

Global Reorganization of Replication Domains During Embryonic Stem Cell Differentiation

DNA replication in mammals is regulated via the coordinate firing of clusters of replicons that duplicate megabase-sized chromosome segments at specific times during S-phase. Cytogenetic studies show that these “replicon clusters” coalesce as subchromosomal units that persist through multiple cell generations, but the molecular boundaries of such units have remained elusive. Moreover, the extent to which changes in replication timing occur during differentiation and their relationship to transcription changes has not been rigorously investigated. We have constructed high-resolution replication-timing profiles in mouse embryonic stem cells (mESCs) before and after differentiation to neural precursor cells. We demonstrate that chromosomes can be segmented into multimegabase domains of coordinate replication, which we call “replication domains,” separated by transition regions whose replication kinetics are consistent with large originless segments. The molecular boundaries of replication domains are remarkably well conserved between distantly related ESC lines and induced pluripotent stem cells. Unexpectedly, ESC differentiation was accompanied by the consolidation of smaller differentially replicating domains into larger coordinately replicated units whose replication time was more aligned to isochore GC content and the density of LINE-1 transposable elements, but not gene density. Replication-timing changes were coordinated with transcription changes for weak promoters more than strong promoters, and were accompanied by rearrangements in subnuclear position. We conclude that replication profiles are cell-type specific, and changes in these profiles reveal chromosome segments that undergo large changes in organization during differentiation. Moreover, smaller replication domains and a higher density of timing transition regions that interrupt isochore replication timing define a novel characteristic of the pluripotent state

Recruitment of Histone Deacetylase 3 to the Interferon-A Gene Promoters Attenuates Interferon Expression

Induction of Type I Interferon (IFN) genes constitutes an essential step leading to innate immune responses during virus infection. Sendai virus (SeV) infection of B lymphoid Namalwa cells transiently induces the transcriptional expression of multiple IFN-A genes. Although transcriptional activation of IFN-A genes has been extensively studied, the mechanism responsible for the attenuation of their expression remains to be determined.In this study, we demonstrate that virus infection of Namalwa cells induces transient recruitment of HDAC3 (histone deacetylase 3) to IFN-A promoters. Analysis of chromatin-protein association by Chip-QPCR demonstrated that recruitment of interferon regulatory factor (IRF)3 and IRF7, as well as TBP correlated with enhanced histone H3K9 and H3K14 acetylation, whereas recruitment of HDAC3 correlated with inhibition of histone H3K9/K14 acetylation, removal of IRF7 and TATA-binding protein (TBP) from IFN-A promoters and inhibition of virus-induced IFN-A gene transcription. Additionally, HDAC3 overexpression reduced, and HDAC3 depletion by siRNA enhanced IFN-A gene expression. Furthermore, activation of IRF7 enhanced histone H3K9/K14 acetylation and IFN-A gene expression, whereas activation of both IRF7 and IRF3 led to recruitment of HDAC3 to the IFN-A gene promoters, resulting in impaired histone H3K9 acetylation and attenuation of IFN-A gene transcription.Altogether these data indicate that reversal of histone H3K9/K14 acetylation by HDAC3 is required for attenuation of IFN-A gene transcription during viral infection