Screening and designing biostimulants using electrochemical sensors and fluorescent bioassay: filling the gap between industry and science.
The empirical development in the biostimulants industry has created a gap between the positive results obtained in plant growth and the scientific knowledge about the mode of action of these biostimulants that favor plant growth.
The aim of the BioScreen project is to screen / evaluate biostimulants with a method based on electrochemical sensors modified selectively for reactive oxygen / nitrogen species (especially peroxynitrite), as these oxidative species modulate plant growth. Confirmation and validation of this method will lead to the creation of an analytical method for the rapid and efficient selection of biostimulants, a method in line with climate change mitigation and with bioeconomy.
Contracting authority: Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI)
Implementation period: 15/05/2022-15/04/2024
Budget: 250.000 lei
Project director: Dr. Chim. Ioana Silvia Hosu
Mentor: Dr. Habil. Florin Oancea
This project proposes the use of peroxynitrite selective biosensors for the screening and the selection between different statistically designed biostimulant formulations, as well as the validation (mainly fluorescent) and the confirmation of the selected compositions with plant bioassays (studying the resistance to salts, accumulation of biomass/ secondary metabolites).
The lack of a strategy in the design of biostimulants must be considered by the scientific community. Biochemical priming is one of the proposed mechanisms in the mode of action of biostimulants and involves increasing tolerance to reactive oxygen / nitrogen species (such as peroxynitrite) under conditions of abiotic stress. Studying and screening different plant mixtures to scavenge these species will lead to faster and more efficient development of biostimulants.
Screening of the activity of some biostimulants with the ROS / RNS sensor.
Deployment period: 15/05/2022 – 31/12/2022
Confirmation of the activity of some biostimulants with the (bio) ROS / RNS sensor by comparison with the results of the biotests.
Deployment period: 01/01/2023 – 31/12/2023
Demonstration of biosensor functionality with ROS / RNS sensors in the selection of synergistic mixtures of plant biostimulants (validation of selected biostimulant mixtures).
Deployment period: 01/01/2024 – 15/04/2024
– formulation of mixtures with biostimulant potential for screening and selection study according to biostimulant effect
– (bio) ROS / RNS sensors developed for biostimulant screening
– initial evaluation / screening of biostimulating compositions by means of (bio) ROS / RNS sensors
– adaptation for plants / cells / tissues / plant extracts of a fluorophore-based method for the determination of biostimulating activity
– application of the modified fluorescent method to mixtures with biostimulant potential, in order to select a synergistic biostimulant mixture.
– comparing the results of electrochemical sensors with the results of the fluorescent method
– demonstration of the effects of biostimulants by biotests on plants (eg measurement of accumulated biomass / assessment of increased resistance to different stress stimuli / determination of the accumulation of other molecules such as secondary metabolites, after treatment with biostimulants).
Scientific papers published
Participation to scientific meetings
The problem that this project aims to solve is the screening (correct selection and/or optimization/design) of biostimulants for plants, since the presence on the market of some empirically developed biostimulants is in contrast to the lack of knowledge of the working mechanisms of them and creates a gap between industry and science. This project proposes the evaluation of plant biostimulants using a fast, efficient and accurate method based on selective sensors for reactive oxygen/nitrogen species, especially for peroxynitrite (ONOO-, PON, the structural isomer of nitrate, which behaves as a strong oxidant, similar to free radicals, although it is a very short-lived anion). The study of peroxynitrite in plants in response to abiotic stress and its role in signaling in plants is not sufficiently studied, although it is considered to play a very large role in these processes, modulating plant growth (together with other reactive oxygen/nitrogen species). The lack of knowledge is driven by the lack of rapid, accurate and sensitive methods in determining PON in plants. We must emphasize that the focus of this project is to develop sensors for screening biostimulants, and not the biostimulants themselves.
Phase I of this project aims to formulate biostimulant mixtures, purchase a low current module and start ROS/RNS sensor development, as well as project management and dissemination activities.
The formulation of biostimulants is carried out by making extracts from plants with antioxidant properties, by methods such as ultrasound, temperature and/or microwaves, as well as classic alcoholic extracts. The development of ROS/RNS sensors (Figure 1.) aims at the corresponding study of the use of different phthalocyanines as potential catalysts for the electro-reduction of peroxynitrite, for the creation of feasible sensors for the study of biostimulants and plants. The development was carried out by two methods: drop-cast and electropolymerization of phthalocyanine solutions (MPc, where M is Co, Mn or H2).
Regarding the management and dissemination activity, the following activities were carried out: participation in an international conference with the results presented at this stage, writing and publishing an ISI-listed article, disseminating the project through the web page and social media (Facebook and Linkedin) and financial management of the project.
The confirmation and validation of this method will be done in the other stages of the project, which will lead to the creation of an analytical method for the rapid and efficient selection of biostimulants, a method in agreement with climate change mitigation and the bioeconomy.
Figure 1. Scheme of the development stages of PON sensitive sensors
Description of progress
Both deliverables from the funding application were fully realized as follows:
D1.1. Report: Formulation of biostimulant compositions – M5 (Activity 1.1)
D1.2. Report: Development of (bio)sensors – M8 (Activity 1.2)
Experimental procedure for measuring the activity of biostimulants
The procedure is described in the subsection “Development of ROS/RNS (bio)sensors” of this scientific report
Communication at an international conference
Participation in an international conference was achieved:
I.S. Hosu*, V. Rădițoiu, A.M.V. Brânzanic, Y. Coffinier, “The influence of different metal phthalocyanines on the electroreduction of peroxynitrite for biosensing”. Poster at PRIOCHEM XVIII International Symposium, Chemistry Priorities for Sustainable Development, XVIII edition, October 26-28, 2022, Bucharest, Romania.
Other dissemination activities