Andrea Acampora

A H2O2-forming peroxidase rather than a NAD(P)H-dependent O2.- synthase may be the major player in cell death responses controlled by the Pto-Fen complex following fenthion treatment

Four tomato (Lycopersicon esculentum Mill.) near-isogenic lines were treated by foliar spraying with the insecticide fenthion. Two, Riogrande and Rimone, differed from each other only for the presence in the latter of the Fen gene, conferring propensity to develop foliar symptoms upon exposure to fenthion. The other two, namely RC332 and RC131, were the transgenic versions of Riogrande and Rimone, respectively, harbouring the Gox gene encoding for glucose oxidase of Aspergillus niger. The production of H2O2 as well as the activities of H+-ATPase, NAD(P)H-dependent superoxide synthase, catalase, peroxidase, and Cu,Zn-superoxide dismutase were evaluated in the foliar tissues up to 24 h after exposure to fenthion. The Fen gene conferred sensitivity to fenthion, regardless of the expression of a Gox transgene. A prolonged accumulation of H2O2 was observed in the leaves of Rimone and of RC131, which was instead transient in Riogrande and in RC332. In all the tomato lines, exposure to fenthion induced rapid but transient changes in the activities of most enzymes. The only exception was peroxidase activity in the leaves of Rimone and of RC131, which steadily increased until the end of the sampling period. It is suggested that the sensitivity of Rimone to fenthion might be due to the sustained activity of a H2O2-forming peroxidase.

A Mower-Conditioner to Improve Fiber Sorghum Plant Drying

Abstract. Fiber sorghum [( L. (Moench.)] is recognized as having potential as an energy crop to allocate towards biogas or bioethanol production. However, due to the considerable amount of biomass produced, the harvesting presents some drawbacks. In Italy the cultivation of fiber sorghum is concentrated in the North where the harvesting occurs at the end of summer, on plants having, on average, 70% of moisture. For allowing the storage in bales, a product with at least 30% of moisture is required. Drying time of non-conditioned plants in open field may be too long, exposing the mowed biomass to adverse climatic conditions that may negatively affect the drying time and the success of the subsequent baling. The work presents the first results of a new mower-conditioner designed by CREA-ING (Rome-ITALY) able to guarantee high efficiency in stem conditioning. The experimental tests were conducted in northern Italy where the performance of the machine was analyzed. Importantly, the mechanical action of conditioning apparatus determined a deeper cracking along the stem. As a result, the time required to reach the minimum moisture threshold (30%) for baling was reduced to 72 h hafter mowing. After just 5 days from conditioning, the moisture content was around 20%. To our knowledge, compared with the data of the available literature, this is the best result on drying time. Moreover, the regression analysis showed that for this specific study, none of the tested climatic parameters resulted in a decrease of moisture content in the sorghum biomass, thus confirming that the drying is mainly due to the conditioning action.