http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. 2013-05-21T20:11:07Z http://hdl.handle.net/2067/1849 Title: The parthenocarpic fruit (pat) mutant of tomato (Lycopersicon esculentum Mill.) sets seedless fruits and has aberrant anther and ovule development Authors: Mazzucato, Andrea; Taddei, Anna Rita; Soressi, Gian Piero Abstract: Among the different sources of genetic parthenocarpy described in tomato, the mutation referred to as parthenocarpic fruit (pat) is of particular interest because of its strong expressivity and because it confers better earliness, higher fruit set and enhanced fruit quality. As a pleiotropic effect, pat flowers have aberrantly developing androecia and reduced male and female fertility. In this work we extend the early description of the pat phenotype by investigating the expression of parthenocarpy in three different environments and by using light and scanning electron microscopy to analyse the development of male and female floral organs. The degree of parthenocarpy was high in the three experimental environments and was characterised by an initiation of ovary growth anticipated to pre-anthesis floral stages. Aberrations in anther development were evident at flower bud stages and resulted in shorter, irregular and teratoid organs. Ectopic production of carpel-like structures bearing external ovules was evident in the most severely altered androecia. Analysis of ovule development revealed that a fraction of pat ovules becomes aberrant from very early stages, having defective integument growth. Meiosis was irregular in aberrant ovules and megaspores or gametes production was severely hampered. The described pat syndrome suggests that parthenocarpy in this mutant could be a secondary effect of a gene controlling, at early stages, organ identity and development. Description: L'articolo é disponibile sul sito dell'editore: http://dev.biologists.org/ 1997-12-31T23:00:00Z http://hdl.handle.net/2067/2261 Title: Livelli di attività antiproteinasiche in piante transgeniche di pomodoro esprimenti inibitori di proteinasi a serina e a cisteina Authors: Farisei, Francesca; Panichi, Daniela; Poerio, Elia; Speranza, Stefano; Pucci, Claudio; Fonzo, Valentina; Caccia, Riccardo; Soressi, Gian Piero Abstract: Tomato plants transgenic for genes coding for protein inhibitors, were tested in order to evaluate their capability to inhibit the commercial proteinase activities as well as those present in the midgut of the phytophagous insect Helicoverpa armigera. Leaf extracts of Pi-IV (gene from soybean coding for a Bowman-Birk-like trypsin inhibitor) transgenic T3 plants (cv. UC-82) are able to inhibit bovine pancreatic trypsin and trypsin-like activity of the phytophagous insect 4 times more than control plant extracts; extracts of KTI3 (gene from soybean coding for a Kunitz-like tripsine inhibitor) transgenic T3 plants (cv. Riogrande) are able to inhibit bovine pancreatic trypsin and trypsin-like activity of the insect 200 times more than control plant extracts; leaf extracts of AtCys (gene from Arabidopsis coding for a cysteine protease inhibitor) transgenic T2 plants (cv. Riogrande) are able to inhibit commercial papain and cysteine-like activity of the insect 4 times more than control plant extracts. On the basis of the data it would be interesting, for both speculative and applicative purposes, to use these transgenic plants in order to verify in vivo the action on the mortality and/or on the reproduction ability of the H. armigera, particularly dangerous to the tomato crop. 2003-12-31T23:00:00Z http://hdl.handle.net/2067/2270 Title: Biosaggi plurigenerazionali sull’Helicoverpa armigera (Hüb.) (Lepidoptera, Noctuidae) alimentata con foglie di pomodoro transgenico per il gene KTI3 (Kunitz) Authors: Speranza, Stefano; Fonzo, Valentina; Soressi, Gian Piero; Pucci, Claudio Abstract: H. armigera is, together with aphids, one of the industrial tomato key insects in central Italy. Its trophic action causes a decrease in the marketable production with high social costs for the agricultural operators. The aim of the present work was to perform a bioassay on the cotton bollworm, feeding the larva with Kunitz proteinase inhibitor coded by the KTI3 gene transgenic plant leaves. The molecules belonging to the Kunitz family have a molecular weight of 21-24 kDa and inhibit the serine proteinase, resulting active in the pH interval 9-11, that is the distinctive interval of Lepidoptera larva midgut. Riogrande cultivar tomato plants were transformed with the KTI3 gene through Agrobacterium tumefaciens. The analysis of the data obtained and their elaboration show a direct effect (negative) on the Lepidoptera biology, particularly in the second generation; this result could have, in the future, a direct containment action of the phytophagous populations in nature, causing a relevant decrease of the marketable production cull percentage. 2003-12-31T23:00:00Z http://hdl.handle.net/2067/2323 Title: Tomato plants transgenic for an Arabidopsis thaliana cystein proteinase inhibitor (Atcys) impair the life cycle of Helicoverpa armigera (Hüb.) Authors: Speranza, Stefano; Caccia, Riccardo; Fonzo, Valentina; Pucci, Claudio; Soressi, Gian Piero Abstract: Atcys tomato (Lycopersicon esculentum Mill.) transgenic plants, expressing a cystein proteinase inhibition level double than the untransformed control (Speranza et al. in press), were used for in vivo assays with H. armigera larvae. This insect pest, extremely polyphagous, has recently caused severe damages to the outdoor tomato crop due to the dropping of infested young fruits and to fruit rotting because of the larval galleries. Plants of the cv. Riogrande (RIG) and of the corresponding Atcys homozygous transgenic line (BG-106) were grown in greenhouse and leaves utilized for feeding H. armigera larvae, reared for four days with artificial diet. The recorded data were larval weight (every two days until the cocoon stage), cocoon sex and morphometric traits, number of adults emerged from the cocoon, number of layed and hatched eggs. The mean weight was generally higher when larvae were fed with BG-106 leaves. By subdividing in three periods the larval life, no difference in mortality was observed between larvae reared with control (RIG) and with BG-106 leaves. The percentage of adults emerged from the cocoon was 81% and 76% for the control and BG-106 respectively. The sex ratio (males/females) was in favour of the female sex both for the RIG (0.87) and BG-106 (0.73) cocoons. On average, the fertility (number of layed eggs) of the BG-106 fed females was 33% lower than the control. By considering the percentage of hatched eggs (emerged larvae), the value obtained was 6.8% for BG-106 against 11% for RIG. According to these data, in Atcys transgenic tomato (BG-106), a level of cystein proteinase inhibition double than the untransformed control, is sufficient to negatively influence the H. armigera biological cycle, even if the weight of the larvae fed with the BG-106 leaves is on average higher than the control (RIG). The last datum is in agreement with similar experiments reported in literature where the effect of proteinase inhibitors is tested in different host-pest systems. 2000-12-31T23:00:00Z http://hdl.handle.net/2067/2322 Title: BBI and Kunitz serin-protease inhibitor action in tomato transgenic plants towards Helicoverpa armigera larvae Authors: Caccia, Riccardo; Schettino, Maria; Farisei, Francesca; Savazzini, Federica; Poerio, Elia; Speranza, Stefano; Pucci, Claudio; Soressi, Gian Piero Abstract: Several crop varieties with agronomically-compatible levels of resistance to insects have been generated by Bt gene transfer. Plant proteinaceous proteinase inhibitors have potential for increasing resistance of crop to insect pests. Proteolytic activities in the larval guts of Helicoverpa armigera (a major pest of solanaceae) have been investigated and proved to be largely due to extracellular serine proteinases (trypsin- and chymotrypsin-like activities) with alkaline pH optimum. With the aim of obtaining tomato transgenic plants resistant to H. armigera larvae, we transformed - the cultivar Riogrande with the gene KTI3 (coding for a soybean Kunitz Inhibitor) and the cultivar UC-82 with the gene Pi-IV (coding for a soybean Bowman-Birk Inhibitor). Leaf extracts of transgenic plants contained significant levels of inhibitory activities towards both bovine pancreatic trypsin and insect trypsin-like enzyme, on average 187- and 5-fold higher-than controls, respectively. The trypsin inhibiting activity was found stable atdifferent plant phenological phases in fruits and leaves; this activity resulted stable for 24h in detached leaf discs used to feed insects. Both inhibiting activities were able to contrast development of H. armigera larvae, by interferring with midgut trypsin-like activity that was found higher in III-IV ages than other ages. 1998-12-31T23:00:00Z