No abstract

Drought stress imposes a major constraint over a crop yield and can be expected to grow in importance if the climate change predicted comes about. Improved methods are needed to facilitate crop management via the prompt detection of the onset of stress. Here, we report the use of an in vivo OECT (organic electrochemical transistor) sensor, termed as bioristor, in the context of the drought response of the tomato plant. The device was integrated within the plant’s stem, thereby allowing for the continuous monitoring of the plant’s physiological status throughout its life cycle. Bioristor was able to detect changes of ion concentration in the sap upon drought, in particular, those dissolved and transported through the transpiration stream, thus efficiently detecting the occurrence of drought stress immediately after the priming of the defence responses. The bioristor’s acquired data were coupled with those obtained in a high-throughput phenotyping platform revealing the extreme complementarity of these methods to investigate the mechanisms triggered by the plant during the drought stress event.

Environment, biodiversity and ecosystem services are essential to ensure food security and nutrition. Managing natural resources and mainstreaming biodiversity across agriculture sectors are keys towards a sustainable agriculture focused on resource efficiency. Vapour Pressure Deficit (VPD) is considered the main driving force of water movements in the plant vascular system, however the tools available to monitor this parameter are usually based on environmental monitoring. The driving motif of this paper is the development of an in-vivo sensor to monitor the effects of VPD changes in the plant. We have used an in vivo sensor, termed “bioristor”, to continuously monitor the changes occurring in the sap ion’s status when plants experience different VPD conditions and we observed a specific R (sensor response) trend in response to VPD. The possibility to directly monitor the physiological changes occurring in the plant in different VPD conditions, can be used to increase efficiency of the water management in controlled conditions thus achieving a more sustainable use of natural resources.

Su blimates were sampled at the Fossa crater of VuIcano Island (Sicily, Italy) in June and October 199 1. Sampling was carried out by means of silica tubes inserted as deep as possible into those fumarolic vents around which lead and bismuth sulphides and sulphosalts occurred. The main mineralogical phases found within the silica tubes are native sulphur, ammonium tetrafluoroborate, lead and bismuth chlorides, oxychlorides, sulphochlorides, sulphides and sulphosalts. The lead and bismuth mineral assemblage is interpreted as the result of the transport of lead and bismuth as volatile chlorides. Microtextural and microanalytical studies (SEM + EDS) on chloro-sulphides and sulphosalts suggest that the latter were deposited from metastable chlorosulphides through reactions involving gaseous H2S. The absence of chlorosulphides on the ground confirms their metastability. The lack of sulphates in the mineralogical association sampled within the silica tubes is due to the reducing conditions of voIcanic fluids.