http://ktisis.cut.ac.cy/handle/10488/4903 Search the Channel search http://ktisis.cut.ac.cy/simple-search http://ktisis.cut.ac.cy/handle/10488/7849 Title: Cell wall physicochemical aspects of nectarine fruit related to flesh reddening symptoms<br/><br/>Authors: Manganaris, George A.; Mignani, Ilaria; Vasilakakis, Miltiadis<br/><br/>Abstract: Flesh reddening (FR) symptoms are developed in many nectarine cultivars, without however having dissected its cell wall physicochemical aspects. ‘Caldesi 2000’ is a very susceptible nectarine to FR and was used as model cultivar in the current study. Two lots of 30 fruits were allowed to ripen for 5 d (shelf life) at 20°C either after harvest or after 4-week cold storage and the fruits with either white or reddish flesh surface were selected for cell wall analysis. Fruits with FR symptoms were characterized by a lower content of uronic acid in the insoluble pectin fraction, and therefore a lower proportion of uronic acid in the insoluble to water-soluble pectin fraction. The decrease of neutral sugar content was mainly attributed to cold storage. However, the fruits with FR symptoms were characterized by a lower content of total neutral sugars. Additionally, significant differences in glucose content were monitored between the white flesh fruits and the fruits with FR symptoms. The nectarine fruits subjected to cold storage were characterized by a decreased cellulose content, whereas the decrease was more intense in nectarines with FR symptoms. http://ktisis.cut.ac.cy/handle/10488/7823 Title: Production of virus-free plant propagation material from infected nectarine trees<br/><br/>Authors: Manganaris, George A.; Economou, A.S; Boubourakas, I.N.<br/><br/>Abstract: Plum pox virus (PPV) is one of the major and common diseases in stone-fruit trees. The effect of thermotherapy in PPV-infected nectarine plants (Prunus persica var. nectarina Max, cv. Arm King) and plant regeneration from meristem-tip explants, as well as use of a reliable RT-PCR that detects extremely low virus titre of PPV in in vitro cultures were studied. Three weeks of thermotherapy at a maximum temperature of 35°C gave tender explants that used for meristem-tip culture. Meristem-tip explants first were established on WPM free of growth regulators and then for multiple shoot were subcultured on WPM supplemented with 8 µM BA and 0.8 µM IAA. Individual shoots produced from such meristem-tip cultures were tested for PPV presence with RT-PCR and gave ‘negative’ results (virus-free) at a frequency of 82.8%. Rooted in vitro microcuttings, derived from virus-free cultures, were established in the greenhouse conditions successfully. http://ktisis.cut.ac.cy/handle/10488/6595 Title: Protein dynamics and spectroscopy for ferryl intermediate of cytochrome c oxidase: a molecular dynamics approach<br/><br/>Authors: Varotsis, Constantinos; Daskalakis, Evangelos; Farantos, Stavros C.<br/><br/>Abstract: Cytochrome c oxidase is the membrane bound terminal enzyme in the respiratory chain. Molecular oxygen is reduced to water in its heme Fe/Cu B active site. The O-O bond cleavage produces the ferryl-oxo (Fe IV=O) intermediate. Molecular Dynamics calculations for a part of the protein containing over 8600 atoms are employed to probe the frequencies of vibrational modes which involve the stretching of Fe-O during protonation/deprotonation events near the active site. The role of protein frame for the spectroscopic properties of the ferryl intermediate is proved to be significant, as the intensity of the oxygen sensitive bands is controlled by conformational changes. In addition, the mechanism of the release of the produced water molecules is examined by changing the protonation state of a residue in the entrance of a proton pathway in the enzyme http://ktisis.cut.ac.cy/handle/10488/6461 Title: A comparative transcriptomic approach to elucidate common and divergent mechanisms involved in apricot and peach fruit development and ripening<br/><br/>Authors: Manganaris, George A.; Ziliotto, Fiorenza; Rasori, Angela<br/><br/>Abstract: Transcript profiling methods are increasingly used to understand the biological basis of growth and development, and fruit quality in the case of fruits. Such methods provide information for thousands of genes, including those of still unknown function. Furthermore, high-throughput methodologies can be used for comprehensive transcriptome analyses, which may lead to further elucidation of fruit growth and development. Microarray is an attractive genomic tool, since it can be used in a heterologous fashion for gene discovery and characterization in species where few resources are available. In the current study, the progress of apricot (Prunus armeniaca cv. Goldrich) fruit ripening during the last developmental stages was monitored and microarray data that were produced were used for comparative in silico studies with data reported during the transition of peach and nectarine fruits from pre-climacteric to climacteric stage. Transcriptomic studies for both fruit species were carried out using the first available peach microarray (μPEACH 1.0) that contains 4,806 oligonucleotides, each corresponding to a single unigene. Intriguingly, a sharp increase of transcript levels in genes regulating an array of heat shock proteins was detected in apricot fruit, which was not the case during nectarine fruit ripening. In addition, we focused on transcript levels of auxin regulated proteins and their role during the last phases of fruit ripening. Overall, data of the present study offers an initial descriptive picture of transcript profiling of novel key genes and their putative role during the last stages of fruit development is challenged. A future perspective, which will also encompass data validation for genes of interest, is the unravelling of the mechanisms underlying the ripening process in stone-fruits, through the identification of genes differentially expressed during peach and apricot ripening and their correlation with traits of agronomic interest