http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Wed, 19 Jun 2013 08:13:06 GMT 2013-06-19T08:13:06Z http://hdl.handle.net/2067/1413 Title: Increasing the amylose content of durum wheat through silencing of the SBEIIa genes Authors: Sestili, Francesco; Janni, Michela; Doherty, Angela; Botticella, Ermelinda; D'Ovidio, Renato; Masci, Stefania; Jones, Huw D.; Lafiandra, Domenico Abstract: Background: High amylose starch has attracted particular interest because of its correlation with the amount of Resistant Starch (RS) in food. RS plays a role similar to fibre with beneficial effects for human health, providing protection from several diseases such as colon cancer, diabetes, obesity, osteoporosis and cardiovascular diseases. Amylose content can be modified by a targeted manipulation of the starch biosynthetic pathway. In particular, the inactivation of the enzymes involved in amylopectin synthesis can lead to the increase of amylose content. In this work, genes encoding starch branching enzymes of class II (SBEIIa) were silenced using the RNA interference (RNAi) technique in two cultivars of durum wheat, using two different methods of transformation (biolistic and Agrobacterium). Expression of RNAi transcripts was targeted to the seed endosperm using a tissue-specific promoter. Results: Amylose content was markedly increased in the durum wheat transgenic lines exhibiting SBEIIa gene silencing. Moreover the starch granules in these lines were deformed, possessing an irregular and deflated shape and being smaller than those present in the untransformed controls. Two novel granule bound proteins, identified by SDS-PAGE in SBEIIa RNAi lines, were investigated by mass spectrometry and shown to have strong homologies to the waxy proteins. RVA analysis showed new pasting properties associated with high amylose lines in comparison with untransformed controls. Finally, pleiotropic effects on other starch genes were found by semi-quantitative and Real-Time reverse transcription-polymerase chain reaction (RT-PCR). Conclusion: We have found that the silencing of SBEIIa genes in durum wheat causes obvious alterations in granule morphology and starch composition, leading to high amylose wheat. Results obtained with two different methods of transformation and in two durum wheat cultivars were comparable. Description: L'articolo è disponibile sul sito dell'editore: http://www.biomedcentral.com Thu, 31 Dec 2009 23:00:00 GMT http://hdl.handle.net/2067/1413 2009-12-31T23:00:00Z http://hdl.handle.net/2067/2178 Title: QTL analysis of durum wheat using microsatellite for genetic map Authors: Yousefi Javan, Iman; Pagnotta, Mario Augusto; D'Ovidio, Renato Thu, 31 Dec 2009 23:00:00 GMT http://hdl.handle.net/2067/2178 2009-12-31T23:00:00Z http://hdl.handle.net/2067/1356 Title: Engineering the cell wall by reducing de-methyl-esterified homogalacturonan improves saccharification of plant tissues for bioconversion Authors: Lionetti, Vincenzo; Francocci, Fedra; Ferrari, Simone; Volpi, Chiara; Bellincampi, Daniela; Galletti, Roberta; D'Ovidio, Renato; De Lorenzo, Giulia; Cervone, Felice Abstract: Plant cell walls represent an abundant, renewable source of biofuels and other useful products. The major bottleneck for the industrial scale-up of their conversion to simple sugars (saccharification) is their recalcitrance to enzymatic hydrolysis. We demonstrated that the structure of pectin affects the exposure of cellulose to enzymes and consequently the process of saccharification.; Le pareti cellulari vegetali rappresentano una abbondante e rinnovabile sorgente di biocarburanti ed altri prodotti utili. Una delle maggiori difficoltà nell’utilizzo delle pareti cellulari a livello industriale è la loro conversione in zuccheri semplici (saccarificazione) in quanto sono estremamente resistenti all’idrolisi enzimatica. In questo lavoro dimostriamo che la struttura della pectina influenza l’esposizione della cellulosa all’azione enzimatica e conseguentemente il processo di saccarificazione. Thu, 31 Dec 2009 23:00:00 GMT http://hdl.handle.net/2067/1356 2009-12-31T23:00:00Z http://hdl.handle.net/2067/1700 Title: Comparative proteomic and transcriptional profiling of a bread wheat cultivar and its derived transgenic line over-expressing a low molecular weight glutenin subunit gene in the endosperm Authors: Scossa, Federico; Laudencia-Chingcuanco, Debby L.; Anderson, Olin D.; Vensel, William H.; Lafiandra, Domenico; D'Ovidio, Renato; Masci, Stefania Abstract: In this paper, a parallel transcriptional and proteomic comparison of seeds from a transformed bread wheat line that over-expresses a transgenic low molecular weight glutenin subunit gene relative to the corresponding non-transformed genotype, has been carried out. Proteomic analyses showed that, during seed development, several classes of endosperm proteins were differentially accumulated in the transformed endosperm. As a result of the strong increase in the amount of the transgenic protein, the endogenous glutenin subunit, all sub-classes of gliadins, and metabolic as well as Chloroform/Methanol soluble proteins were diminished in the transgenic genotype. The differential accumulation detected by proteomic analyses, both in mature and developing seeds, was paralleled by the corresponding changes in transcript levels detected by microarray experiments. Our results suggest that the most evident effect of the strong over-expression of the transgenic glutenin gene consists in a global compensatory response involving a significant decrease in the amounts of polypeptides belonging to the prolamin superfamily. It is likely that such compensation is a consequence of the diversion of amino acid reserves and translation machinery to the synthesis of the transgenic glutenin subunit. Mon, 31 Dec 2007 23:00:00 GMT http://hdl.handle.net/2067/1700 2007-12-31T23:00:00Z http://hdl.handle.net/2067/1785 Title: The expression of a bean PGIP in transgenic wheat confers increased resistance to the fungal pathogen Bipolaris sorokiniana Authors: Janni, Michela; Sella, Luca; Favaron, Francesco; Blechl, Ann E.; De Lorenzo, Giulia; D'Ovidio, Renato Abstract: In several plant-pathogen interactions to overcome the barrier represented by cell wall most fungal pathogens produce a variety of hydrolytic enzymes and between them PGs are one of the first to be secreted. We demonstrate that transgenic wheat plants expressing PvPGIP2 showed a significant reduction of symptoms following the infection of Bipolaris sorokiniana suggesting that pectin hydrolysis is an important step for fungal penetration of wheat plants.; In molti sistemi pianta patogeno i patogeni al fine di superare l’ostacolo rappresentato dalla parete cellulare producono degli enzimi idrolitici tra cui le Poligalatturonasi ( PG) sono tra i primi ad essere secreti. In questo lavoro dimostriamo che piante transgeniche di frumento sovraesprimenti la PvPGIP2 mostrano una significativa riduzione nella sintomatologia riscontrata in seguito ad infezione con Bipolaris sorokiniana suggerendo che l’idrolisi della pectina rappresenta uno step importante per la penetrazione e la colonizzazione dei tessuti di frumento. Description: L'articolo é disponibile sul sito dell'editore: http://www.apsjournals.apsnet.org Mon, 31 Dec 2007 23:00:00 GMT http://hdl.handle.net/2067/1785 2007-12-31T23:00:00Z