PREMIVM – improving grape quality with multiparametric field analysis of grapes and leaves in vineyards

European wine industry is a strategic economic sector that is nowadays facing a growing competition in the international market at the same time it as to deal with predictable lower support from the CAP. Taking into consideration that the use of ICT can support the development of new tools and devices that can reduce costs and increase final product quality/quantity an international consortium that comprises 3 technical companies and 3 winegrowers together with 3 research groups setup the EU Project PREMIVM. In this work will present the PREMIVM decision support system that was developed including the field device for data collection - WINEPEN, the web information management system for data storage, processing and information visualization, and the smartphone interface for information deliveryinfo:eu-repo/semantics/publishedVersio

Towards remote sensing of vegetation processes

The latest advances in imaging spectroscopy of vegetation enabled remote sensing (RS) of plant reflected or emitted signals associated with photosynthetic processes as the photoprotective transformation of xanthophyll pigments or the chlorophyll fluorescence (Chl-F). A potential future European Space Agency (ESA) satellite mission FLEX is expected to sense, apart from other parameters, so-called steady-state chlorophyll fluorescence (Chl-FS) signal, which may be potentially used for monitoring of photosynthesis (vegetation canopy carbon assimilation rate). Nevertheless, geometric complexity of plant canopies and signal disturbing atmospheric factors require a proper approach for scaling the information of a single leaf optical properties up to the RS image data of anisotropic vegetation canopies. Such up-scaling approach can be established only via synergic measurements of ground based and air-/space-borne optical sensors. Our initial experiment revealed that Chl-FS, being strongly driven by the air temperature, is able to accurately indicate onset and off-set of the photosynthetically active period for the evergreen plants. Next field experiment, carried out with the VNIR imaging spectroradiometer AISA Eagle (SPECIM Ltd., Finland) mounted above the montane grassland and Norway spruce (Picea abies /L./ Karst.) canopies, showed that the fluorescence signal is retrievable from passive optical imaging spectroscopy data. Further analyses revealed that some of the vegetation \u27process-related\u27 optical indices (e.g., photochemical reflectance index - PRI) are closely correlated to the parameters measured over the experimental canopies by eddy-covariance flux systems. The future objective is to continue in development the leaf-canopy Chl-F up-scaling approach by setting up local scale experiments employing the field pocket-size cost effective instruments measuring the leaf optical indices and Chl-F parameters simultaneously with canopy reflectance acquired by RS sensors from tower and aircraft platforms

A combined phenotypic and metabolomic approach for elucidating the biostimulant action of a plant-derived protein hydrolysate on tomato grown under limited water availability

Plant-derived protein hydrolysates (PHs) are an important category of biostimulants able to increase plant growth and crop yield especially under environmental stress conditions. PHs can be applied as foliar spray or soil drench. Foliar spray is generally applied to achieve a relatively short-term response, whereas soil drench is used when a long-term effect is desired. The aim of the study was to elucidate the biostimulant action of PH application method (foliar spray or substrate drench) on morpho-physiological traits and metabolic profile of tomato grown under limited water availability. An untreated control was also included. A high-throughput image-based phenotyping (HTP) approach was used to non-destructively monitor the crop response under limited water availability (40% of container capacity) in a controlled environment. Moreover, metabolic profile of leaves was determined at the end of the trial. Dry biomass of shoots at the end of the trial was significantly correlated with number of green pixels (R2 = 0.90) and projected shoot area, respectively. Both drench and foliar treatments had a positive impact on the digital biomass compared to control while the photosynthetic performance of the plants was slightly influenced by treatments. Overall drench application under limited water availability more positively influenced biomass accumulation and metabolic profile than foliar application. Significantly higher transpiration use efficiency was observed with PH-drench applications indicating better stomatal conductance. The mass-spectrometry based metabolomic analysis allowed the identification of distinct biochemical signatures in PH-treated plants. Metabolomic changes involved a wide and organized range of biochemical processes that included, among others, phytohormones (notably a decrease in cytokinins and an accumulation of salicylates) and lipids (including membrane lipids, sterols, and terpenes). From a general perspective, treated tomato plants exhibited an improved tolerance to reactive oxygen species (ROS)-mediated oxidative imbalance. Such capability to cope with oxidative stress might have resulted from a coordinated action of signaling compounds (salicylic acid and hydroxycinnamic amides), radical scavengers such as carotenoids and prenyl quinones, as well as a reduced biosynthesis of tetrapyrrole coproporphyrins

Dissecting the interaction of photosynthetic electron transfer with mitochondrial signalling and hypoxic response in the Arabidopsis rcd1 mutant

The Arabidopsis mutant rcd1 is tolerant to methyl viologen (MV). MV enhances the Mehler reaction, i.e. electron transfer from Photosystem I (PSI) to O-2, generating reactive oxygen species (ROS) in the chloroplast. To study the MV tolerance of rcd1, we first addressed chloroplast thiol redox enzymes potentially implicated in ROS scavenging. NADPH-thioredoxin oxidoreductase type C (NTRC) was more reduced in rcd1. NTRC contributed to the photosynthetic and metabolic phenotypes of rcd1, but did not determine its MV tolerance. We next tested rcd1 for alterations in the Mehler reaction. In rcd1, but not in the wild type, the PSI-to-MV electron transfer was abolished by hypoxic atmosphere. A characteristic feature of rcd1 is constitutive expression of mitochondrial dysfunction stimulon (MDS) genes that affect mitochondrial respiration. Similarly to rcd1, in other MDS-overexpressing plants hypoxia also inhibited the PSI-to-MV electron transfer. One possible explanation is that the MDS gene products may affect the Mehler reaction by altering the availability of O-2. In green tissues, this putative effect is masked by photosynthetic O-2 evolution. However, O-2 evolution was rapidly suppressed in MV-treated plants. Transcriptomic meta-analysis indicated that MDS gene expression is linked to hypoxic response not only under MV, but also in standard growth conditions. This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'.Peer reviewe

Dissecting the interaction of photosynthetic electron transfer with mitochondrial signalling and hypoxic response in the Arabidopsis rcd1 mutant

The Arabidopsis mutant rcd1 is tolerant to methyl viologen (MV). MV enhances the Mehler reaction, i.e. electron transfer from Photosystem I (PSI) to O-2, generating reactive oxygen species (ROS) in the chloroplast. To study the MV tolerance of rcd1, we first addressed chloroplast thiol redox enzymes potentially implicated in ROS scavenging. NADPH-thioredoxin oxidoreductase type C (NTRC) was more reduced in rcd1. NTRC contributed to the photosynthetic and metabolic phenotypes of rcd1, but did not determine its MV tolerance. We next tested rcd1 for alterations in the Mehler reaction. In rcd1, but not in the wild type, the PSI-to-MV electron transfer was abolished by hypoxic atmosphere. A characteristic feature of rcd1 is constitutive expression of mitochondrial dysfunction stimulon (MDS) genes that affect mitochondrial respiration. Similarly to rcd1, in other MDS-overexpressing plants hypoxia also inhibited the PSI-to-MV electron transfer. One possible explanation is that the MDS gene products may affect the Mehler reaction by altering the availability of O-2. In green tissues, this putative effect is masked by photosynthetic O-2 evolution. However, O-2 evolution was rapidly suppressed in MV-treated plants. Transcriptomic meta-analysis indicated that MDS gene expression is linked to hypoxic response not only under MV, but also in standard growth conditions.This article is part of the theme issue 'Retrograde signalling from endosymbiotic organelles'

Lettuce reaction to drought stress: Automated high-throughput phenotyping of plant growth and photosynthetic performance

The unavailability of fresh water is one of the main concerns for horticulture nowadays and it is supposed to get worse in the coming future. Some crops are more vulnerable than others to drought stress such as leafy vegetables. It is therefore essential to identify and select cultivars that can overcome this kind of abiotic stress with limited or no substantial reduction in final yield, and to do it in a fast and effective way. High throughput phenotyping combined with advances in genome sequences provide efficient and reproducible approaches that are facilitating the discovery of genes and cultivars with improved plant performance under sub-optimal conditions. Drought resistance of two different Salanova® cultivars, ‘Aquino’ (green butterhead) and ‘Barlach’ (red butterhead), was tested, by using PlantScreen™, a high-throughput non-invasive imaging platform developed at Photon Systems Instruments (PSI, Czech Republic). The two cultivars performed similarly in both control (70% soil water content) and mild drought stress conditions (40% soil water content). The results demonstrated that ‘Aquino’ grew faster in control conditions at early growth phase, while in later phase it is the red ‘Barlach’ that reached larger biomass. In drought conditions growth performance of both cultivars was rapidly compromised. However, ‘Barlach’ grew better and had improved biomass in both control and mild-drought stress conditions in comparison with ‘Aquino’. Light curve protocol was used to address light use efficiency of the two cultivars. Interestingly, we observed a rapid decline in PS II operating efficiency already three days upon mild drought stress initiation. Nevertheless, there was no obvious difference in the performances between the two cultivars. In conclusion, the results of quantitative analysis of plant growth and photosynthetic performance, allowed to set up a protocol for high-throughput image-based analysis of different morpho-physiological traits associated with the early phase of drought response