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Changes in root organization and colonization could be relevant for wheat’s (Triticum durum Desf.) response to F. culmorum-induced crown rot disease (FCR). We investigated the biocontrol and biostimulant efficiency of seeds coated with T. harzianum T-22 (T-22) of four tetraploid wheat seedlings (ancient Saragolle Lucana and modern Creso, Simeto, and Ciclope). In an in vitro experiment, T-22 repressed F. culmorum mycelium growth by over 50% due to the probable combination of competition for nutrients, mycoparasitism, and antibiosis. The seed germination rate was not significantly affected by T-22 while the F. culmorum-induced decrease in emergence was attenuated in the presence of T-22. Ultimately, an improvement in growth was observed by comparing treated and control seedlings at 21 days after sowing. Inoculation with T-22 resulted in Saragolle Lucana seedlings being 4.69 cm higher while Ciclope and Simeto had main roots that were 9.96 and 8.13 cm longer than the control, respectively. Treated and infected Simeto seedlings were 3.75 cm higher and had roots that were 14.45 cm longer than the control, with little contemporary dense coiling colonization by T-22, like Saragolle Lucana. Seed coating induced the best performance regarding seedling growth and the ability to control the pathogen in Simeto (disease severity reduction rate (DDR) of 20%). The pathogenicity of F. culmorum was reduced in all four durum wheats, although it was highly susceptible to FCR. Ciclope, studied for the first time, showed a decrease in disease incidence from 100 ± 0.00% to 56.67 ± 9.13% and a 30% DDR. The seed coating influenced the seedlings’ response to FCR due to T-22’s different colonization actions. This study provides new explanations for the diverse responses of ancient and modern tetraploid wheat to F. culmorum mediated by T-22 inoculation via seed coating.

With the idea of summarizing the outcomes of studies focusing on the resistance induced by Trichoderma spp. against Botrytis cinerea in tomato, the present paper shows, for the first time, results of a meta-analysis performed on studies published from 2010 to 2021 concerning the cross-talk occurring in the tomato–Trichoderma-B. cinerea system. Starting from an initial set of 40 papers, the analysis was performed on 15 works and included nine parameters, as a result of a stringent selection mainly based on the availability of more than one article including the same indicator. The resulting work not only emphasizes the beneficial effects of Trichoderma in the control of grey mold in tomato leaves (reduction in disease intensity, severity and incidence and modulation of resistance genes in the host), but carefully drives the readers to reply to two questions: (i) What are the overall effects of Trichoderma on B. cinerea infection in tomato? (ii) Do the main effects of Trichoderma differ based on the tomato species, Trichoderma species, amount, type and duration of treatment? At the same time, this meta-analysis highlights some weak points of the available literature and should be seen as an invitation to improve future works to better the conceptualization and measure.

Among foods protected by the European Union with the PGI (Protected Geographical Indication) mark, several ecotypes of “Fagioli di Sarconi” common beans, typical legumes of Basilicata Region, are included. This work aimed to conduct a survey of seed-borne pathogens isolated from “Ciuoto” and “Cannellino rosso”, ecotypes of “Fagioli di Sarconi” common beans, in two years and cultivation areas of the National Park of the Agri Valley, for identifying resistant and climatic changes well-adapted genotypes. Three validated methods were used for the seed-borne pathogens screening. Eighteen fungi were differently found for ecotype and year of observation by the washing test. Saprophyte contaminants pathogens isolated and detected by the blotter test were strongly reduced by 1% sodium hypochlorite treatment. Using the between paper test, specific for detecting Colletotrichum lindemuthianum, the presence of this pathogen for both ecotypes, years and cultivation areas, and also some bacteria were individuated. Therefore, area-, environment- and ecotype-dependent differences were revealed, probably also caused by a different polyphenolic content and thickness of integument of two ecotypes. This study represents a baseline information for further studies, development of forecasting models and management of seed-borne diseases associated with common beans.

This study evaluated, for the first time, the suitability of on-farm green compost (GC) from the fourth range sector for the production, in a controlled environment, of six baby leaf species (radish, lettuce, rocket, chard, sorrel and dill), characterized by short cultivation cycles. The pH and electrical conductivity of potting soil-compost mixtures were affected by the different amounts of GC added to the potting soil. Germination tests on Lactuca sativa seeds indicated no phytotoxic effects when GC was used to prepare aqueous extracts diluted at 50% and 25% (v/v). In the pot experiment, GC was used at four different dosages in the growing medium, inducing different impacts on growth parameters, depending on the species and applied dose. The greatest plant growth responses were determined by using less than 3.5 g of GC in 100 g of potting soil. Significant positive correlations between the dry weights of root and shoot (r = 0.77 **), seedling height (r = 0.51 **) and the number of true leaves number (r = 0.56 **) confirmed the close relationship between the root system biomass and the growth parameters of aboveground organs. The study highlights that on-farm green compost, used as partial growing substrate, provides a good opportunity to obtain baby leaf species with well-developed root systems.

Common bean (Phaseolus vulgaris L.) is a major grain legume consumed worldwide with high nutritional value. Seed-borne pathogens represent a serious problem for seeds, causing losses of yield and quality reduction. Basilicata Region (southern Italy) is a traditional, vocational area of bean production, in particular for "Fagioli di Sarconi" common beans, including different ecotypes protected by the European Union with the mark PGI (Protected Geographical Indication). The study aimed to determine the presence of seed-borne pathogens isolated from seeds of two ecotypes of "Fagioli di Sarconi" common beans, "Ciuoto" and "Cannellino rosso", collected from three different cultivation areas of Basilicata Region during the years 2018 and 2019, for identifying genotypes resistant to seed-borne pathogens and well adapted to climatic changes. The seeds were preliminary evaluated for their purity and germinability and treated or not with sodium hypochlorite for seed-borne pathogens screening, by using three validated seed health testing methods, according to the 2020 International Rules for seed testing: washing, blotter and between paper tests. The washing test identified 17 fungal pathogens, different for ecotype and year of observation. Furthermore, the 1% sodium hypochlorite treatment strongly reduced the contaminants maintaining the Rhizoctonia solani, Colletotrichum lindemuthianum, Fusarium oxysporum, Fusarium solani pathogens; instead, using the blotter test, Aspergillus spp., Cladosporium spp., Botrytis spp., Mucor spp., Rhizophus spp. saprophyte pathogens resulted. Finally, between paper test, specific for detecting the C. lindemuthianum, revealed the presence of this pathogen for the both ecotypes and years, in all areas. This assay individuated some bacteria, too.

A screening strategy using micropropagation glass tubes with a gradient of distances between germinating seeds and a metal-contaminated medium was used for studying alterations in root architecture and morphology of Arabidopsis thaliana treated with cadmium (Cd) and zinc (Zn) at the concentration of 10-20μM and 100-200μM, respectively. Metal concentrations in plant shoots and roots were measured by quadrupole inductively coupled plasma mass spectrometry. After 21days from germination, all plants in the tubes were scanned at high resolution and the root systems analyzed. The localization of indole-3-acetic acid (IAA) in the primary root and lateral root apices was monitored using DR5:GUS, LAX3:GUS and AUX1:GUS Arabidopsis transgenic lines. Total phenol content in leaves was measured spectrophotometrically. Shoot and root dry weight and leaf area did not change in Zn-exposed plants and significantly decreased in Cd-exposed plants, compared to control plants. Cadmium induced a reduction of root length, of mean number of roots and of total root surface. Both Cd- and Zn-exposed plants showed a reduced specific root length. This morphological behavior, together with an observed increase in root diameter in metal-exposed plants could be interpreted as compensatory growth, and the observed thicker roots could act as a barrier to protect root from the metals. In comparison with the apical localization of the IAA signal in the control plants, Zn generally reinforced the intensity of IAA signal, without affecting its localization. In Cd-exposed plants, IAA localization remained apical but weaker compared to control plants. Total phenols decreased in plants exposed to Zn and Cd. Therefore, we propose that the remodelling of the root architecture and the production of some secondary metabolites, such as IAA and phenols could be two responses of plants subjected to metal stress. This knowledge can open the way to future phytoremediation strategies of contaminated sites.

In the last few years, the aromatic plant market for fresh consumption has been growing, especially packaged herbs for Mass Market Retailers. Pruning and selection of aromatic plants during packaging leads to the accumulation of a large amounts of plant residues with consequent disposal costs. In a circular economy perspective, the aim of this study was to recover residues of three aromatic plants (Ocimum basilicum L., Rosmarinus officinalis L. and Salvia officinalis L.) by extracting essential oil and aromatic water and, subsequently, reusing oil-free biomasses for composting. In fact, these by-products are currently considered very interesting and sustainable. The essential oils are natural products that have a wide range of biological activities useful for pharmaceutical, medical, veterinary and agriculture innovative purposes. Hydrolates have a much softer scent than the corresponding essential oils. The compost can be successfully applied for the restoration and maintenance of soil fertility. Results of this study showed that yields of essential oils obtained from plant residues, were sufficiently higher, especially for sage and rosemary, also if they were collected well far from plant balsamic period. Analysis of composition of essential oils confirmed the presence of characteristic compounds for each species. The aromatic waters were found to be an easily usable product due to the favourable physicochemical characteristics and, in particular, the aromatic waters of basil showed high antioxidant activity. About compost, the main physicochemical (humidity, pH, electrical conductivity) and biological (basal respiration and hydrolase activity) properties, were considered. Phytotoxicity tests indicated that composts derived from the three species can be used in agriculture. This research demonstrates that it is possible to eliminate completely plant residues and recover new products from aromatic species, supporting the effectiveness of an eco-friendly model to recover and reuse all fresh aromatic plant residues.

Hydrogen peroxide (H2O2), an important relatively stable non-radical reactive oxygen species (ROS) is produced by normal aerobic metabolism in plants. At low concentrations, H2O2 acts as a signal molecule involved in the regulation of specific biological/physiological processes (photosynthetic functions, cell cycle, growth and development, plant responses to biotic and abiotic stresses). Oxidative stress and eventual cell death in plants can be caused by excess H2O2 accumulation. Since stress factors provoke enhanced production of H2O2 in plants, severe damage to biomolecules can be possible due to elevated and non-metabolized cellular H2O2. Plants are endowed with H2O2-metabolizing enzymes such as catalases (CAT), ascorbate peroxidases (APX), some peroxiredoxins, glutathione/thioredoxin peroxidases, and glutathione sulfo-transferases. However, the most notably distinguished enzymes are CAT and APX since the former mainly occurs in peroxisomes and does not require a reductant for catalyzing a dismutation reaction. In particular, APX has a higher affinity for H2O2 and reduces it to H2O in chloroplasts, cytosol, mitochondria and peroxisomes, as well as in the apoplastic space, utilizing ascorbate as specific electron donor. Based on recent reports, this review highlights the role of H2O2 in plants experiencing water deficit and salinity and synthesizes major outcomes of studies on CAT and APX activity and genetic regulation in drought- and salt-stressed plants.

The study of the biochemical and molecular mechanisms deriving from the host-pathogen-antagonist interaction is essential to understand the dynamics of infectious processes and can be useful for the development of new strategies to control phytopathogens, particularly viruses, against which chemical treatments have no effect. In this work, we demonstrate the ability of the rhizospheric fungus Trichoderma harzianum strain T-22 (T22) to induce defense responses in tomato (Solanum lycopersicum var. cerasiforme) against Cucumber mosaic virus (CMV, family Bromoviridae, genus Cucumovirus) strain Fny. A granule formulation containing T22 was used for treating the plants before, simultaneously or after the CMV inoculation, in order to study the molecular and biochemical aspects of the interaction between T22 and tomato against the virus. Reactive oxygen species (ROS) and the genes encoding for ROS scavenging enzymes were investigated. Histochemical analysis revealed a different increase in the superoxide anion ( $$ {\text{O}}_{2}^{ \bullet - } $$ ) and hydrogen peroxide (H2O2) content in plants infected by CMV alone or in the presence of T22, confirming the involvement of ROS in plant defense responses. Gene expression analysis suggested a definite improvement in oxidative stress when plants were treated with T22 after inoculation with CMV. In conclusion, our data indicate that Trichoderma harzianum T-22 stimulates the induction of tomato defense responses against CMV, an action that implies the involvement of ROS, pointing towards its use as a treatment rather than as a preventive measure.

Understanding the induction of plant defenses against viruses using biocontrol agents is essential for developing new strategies against these pathogens, given the ineffectiveness of chemical treatments. The ability of Trichoderma harzianum, strain T-22 (T22) to control Cucumber mosaic virus (CMV) in Solanum lycopersicum var. cerasiforme plants and the changes in the physiology of tomato treated/infected with T22/CMV were examined. Plant growth-promoting effects, photosynthetic performance, reactive oxygen species (ROS) scavenging enzymes, and phytohormones were investigated. T22 improved tomato growth in terms of plant height and improved photosynthesis, total chlorophyll content and plant gas exchange. In contrast, CMV induced a negative effect on dry matter accumulation and inhibited the photosynthetic capacity. The analysis of plant hormones demonstrated that treating with T22 before or simultaneously to CMV infection, led to a systemic resistance by jasmonic acid/ethylene and salicylic acid signaling pathways. Conversely, systemic resistance was abscissic acid-dependent when T22 treatment was administered after the CMV infection. In conclusion, the data reported here indicate that the T22-based strategy may be the most effective measure against CMV.

Nowadays, crop production is at risk due to global warming, especially in Mediterranean areas where the increase of air temperature and/or reduction of precipitation is relevant. Climate changes that are occurring can severely prejudice plant defensive mechanisms during host-pathogen interactions by modifying growth and physiology of the host plant. In particular, viral diseases cause serious economic losses destroying crops and reducing agronomic productivity, and, in some cases such as tomato crops, they become the limiting factor production of both open field and under greenhouse cultivation systems. This is because plant viruses are obligate parasites and require living tissue for their multiplication and spread. Therefore, they are able to interfere with plant metabolism and compete for host plant resources, so determining a decrease of plant growth and productivity. Severe outbreaks of Cucumber mosaic virus (CMV) and other viruses caused disruption of tomato plants in the Mediterranean region and in Southern Italy since the 1970s. In such a scenario, it is necessary to introduce new strategies for controlling plant pathogens and parasites in order to help maintain ecosystems and to boost sustainable agriculture. The aim of this work is to give an up-to-date overview on the recent breakthroughs in the use of microorganisms on plants for improving crop yields, quality and plant tolerance against pathogens. In particular, here we report a case study regarding an innovative strategy to control a viral disease (CMV) in tomato, based on the use of rhizosphere microorganism (Trichoderma harzianum, strain T-22) as an antagonist biocontrol agent (BCA).

The need for new eco-friendly control methods against plant diseases and pests requires that the scientific research is focused on effective tools for a safe environment for humans and animal health. The systemic acquired resistance (SAR) represents a valid opportunity in plant natural protection. Particularly, biocontrol microorganisms (BCMs) can be used as inducers of SAR. At the same time, fungal BCMs are able to promote plant growth and development (so acting as plant growth-promoting microorganisms (PGPMs)) that in turn determine a higher tolerance against abiotic stresses, such as drought and salinity. The ability of BCMs and PGPMs of modulating plant defence mechanisms, like SAR, was demonstrated, but the details of this BCM-plant molecular crosstalk are poorly known and many defensive compounds are likely to exist but remain to be identified. For these reasons, BCMs and PGPMs can be defined as “biostimulant microorganisms”, able to foster plant growth and defence against pathogens throughout the crop life cycle, from seed germination to plant maturity. The aim of this chapter is to give an up-to-date overview on the recent breakthroughs in the use of biostimulant microorganisms on plants for improving crop vigour, yields and quality and for increasing plant tolerance against biotic and abiotic stresses.

To date, almost no information is available in roots and shoots of the model plant Arabidopsis thaliana about the hierarchic relationship between metal accumulation, phytohormone levels, and glutathione/phytochelatin content, and how this relation affects root development. For this purpose, specific concentrations of cadmium, copper and zinc, alone or in triple combination, were supplied for 12 days to in vitro growing seedlings. The accumulation of these metals was measured in roots and shoots, and a significant competition in metal uptake was observed. Microscopic analyses revealed that root morphology was affected by metal exposure, and that the levels of trans-zeatin riboside, dihydrozeatin riboside, indole-3-acetic acid and the auxin/cytokinin ratio varied accordingly. By contrast, under metal treatments, minor modifications in gibberellic acid and abscisic acid levels occurred. Real-time polymerase chain reaction analysis of some genes involved in auxin and cytokinin synthesis (e.g. AtNIT in roots and AtIPT in shoots) showed on average a metal up-regulated transcription. The production of thiol-peptides was induced by all the metals, alone or in combination, and the expression of the genes involved in thiol-peptide synthesis (AtGSH1, AtGSH2, AtPCS1 and AtPCS2) was not stimulated by the metals, suggesting a full post-transcriptional control. Results show that the Cd/Cu/Zn-induced changes in root morphology are caused by a hormonal unbalance, mainly governed by the auxin/cytokinin ratio.