Uncovering the Mechanisms: The Role of Biotrophic Fungi in Activating or Suppressing Plant Defense Responses.

This paper discusses the mechanisms by which fungi manipulate plant physiology and suppress plant defense responses by producing effectors that can target various host proteins. Effector-triggered immunity and effector-triggered susceptibility are pivotal elements in the complex molecular dialogue underlying plant-pathogen interactions. Pathogen-produced effector molecules possess the ability to mimic pathogen-associated molecular patterns or hinder the binding of pattern recognition receptors. Effectors can directly target nucleotide-binding domain, leucine-rich repeat receptors, or manipulate downstream signaling components to suppress plant defense. Interactions between these effectors and receptor-like kinases in host plants are critical in this process. Biotrophic fungi adeptly exploit the signaling networks of key plant hormones, including salicylic acid, jasmonic acid, abscisic acid, and ethylene, to establish a compatible interaction with their plant hosts. Overall, the paper highlights the importance of understanding the complex interplay between plant defense mechanisms and fungal effectors to develop effective strategies for plant disease management.

Fine-Tuning of Arabidopsis thaliana Response to Endophytic Colonization by Gluconacetobacter diazotrophicus PAL5 Revealed by Transcriptomic Analysis.

Gluconacetobacter diazotrophicus is a diazotrophic endophytic bacterium that promotes the growth and development of several plant species. However, the molecular mechanisms activated during plant response to this bacterium remain unclear. Here, we used the RNA-seq approach to understand better the effect of G. diazotrophicus PAL5 on the transcriptome of shoot and root tissues of Arabidopsis thaliana. G. diazotrophicus colonized A. thaliana roots and promoted growth, increasing leaf area and biomass. The transcriptomic analysis revealed several differentially expressed genes (DEGs) between inoculated and non-inoculated plants in the shoot and root tissues. A higher number of DEGs were up-regulated in roots compared to shoots. Genes up-regulated in both shoot and root tissues were associated with nitrogen metabolism, production of glucosinolates and flavonoids, receptor kinases, and transcription factors. In contrast, the main groups of down-regulated genes were associated with pathogenesis-related proteins and heat-shock proteins in both shoot and root tissues. Genes encoding enzymes involved in cell wall biogenesis and modification were down-regulated in shoots and up-regulated in roots. In contrast, genes associated with ROS detoxification were up-regulated in shoots and down-regulated in roots. These results highlight the fine-tuning of the transcriptional regulation of A. thaliana in response to colonization by G. diazotrophicus PAL5.

Nitrogen and Silicon Contribute to Wheat Defense's to Pyrenophora tritici-repentis, but in an Independent Manner.

Nitrogen (N) and silicon (Si) are mineral elements that have shown a reduction in the damage caused by tan spot (Pyrenophora tritici-repentis (Ptr)) in wheat. However, the effects of these elements were studied separately, and the N and Si interaction effect on wheat resistance to tan spot remains elusive. Histocytological and biochemical defense responses against Ptr in wheat leaves treated with Si (+Si) at low (LN) and high N (HN) inputs were investigated. Soil amendment with Si reduced the tan spot severity in 18% due to the increase in the leaf Si concentration (around 30%), but it was affected by the N level used. The superoxide dismutase (SOD) activity was higher in +Si plants and inoculated with Ptr, leading to early and higher H2O2 and callose accumulation in wheat leaf. Interestedly, phenylalanine ammonia-lyase (PAL) activity was induced by the Si supplying, being negatively affected by the HN rate. Meanwhile, catalase (CAT), and peroxidase (POX) activities showed differential response patterns according to the Si and N rates used. Tan spot severity was reduced by both elements, but their interaction does not evidence synergic effects in this disease's control. Wheat plants from -Si and HN and +Si and LN treatments recorded lower tan spot severity.

Carbon-based nanomaterials as inducers of biocompounds in plants: Potential risks and perspectives.

Biocompounds are metabolites synthesized by plants, with clinically proven capacity in preventing and treating degenerative diseases in humans. Carbon-based nanomaterials (CNMs) are atomic structures that assume different hybridization and shape. Due to the reactive property, CNMs can induce the synthesis of metabolites, such as biocompounds in cells and various plant species, by generating reactive oxygen species (ROS). In response, plants positively or negatively regulate the expression of various families of genes and enzymes involved in physiological and metabolomic pathways of plants, such as carbon and nitrogen metabolism, which are directly involved in plant development and growth. Likewise, ROS can modulate the expression of enzymes and genes related to the adaptation of plants to stress, such as the glutathione ascorbate cycle, the shikimic acid, and phenylpropanoid pathways, from which the largest amount of biocompounds in plants are derived. This document exposes the ability of three CNMs (fullerene, graphene, and carbon nanotubes) to positively or negatively regulate the activity of enzymes and genes involved in various plant species' primary and secondary metabolism. The mechanism of action of CNMs on the production of biocompounds and the effect of the translocation of CNMs on the growth and content of primary metabolites in plants are described. Adverse effects of CNMs on plants, prospects, and possible risks involved are also discussed. The use of CNMs as inducers of biocompounds in plants could have implications and relevance for human health, crop quality, and plant adaptation and resistance to biotic and abiotic stress.

Alterations in Gene Expression during Incompatible Interaction between Amendoim Cavalo Common Bean and Colletotrichum lindemuthianum.

Anthracnose, caused by the fungus Colletotrichum lindemuthianum, poses a significant and widespread threat to the common bean crop. The use of plant genetic resistance has proven to be the most effective strategy for managing anthracnose disease. The Amendoim Cavalo (AC) Andean cultivar has resistance against multiple races of C. lindemuthianum, which is conferred by the Co-AC gene. Fine mapping of this resistance gene to common bean chromosome Pv01 enabled the identification of Phvul.001G244300, Phvul.001G244400, and Phvul.001G244500 candidate genes for further validation. In this study, the relative expression of Co-AC candidate genes was assessed, as well as other putative genes in the vicinity of this locus and known resistance genes, in the AC cultivar following inoculation with the race 73 of C. lindemuthianum. Gene expression analysis revealed significantly higher expression levels of Phvul.001G244500. Notably, Phvul.001G244500 encodes a putative Basic Helix-Loop-Helix transcription factor, suggesting its involvement in the regulation of defense responses. Furthermore, a significant modulation of the expression of defense-related genes PR1a, PR1b, and PR2 was observed in a time-course experiment. These findings contribute to the development of improved strategies for breeding anthracnose-resistant common bean cultivars, thereby mitigating the impact of this pathogen on crop yields and ensuring sustainable bean production.

Brevipalpus yothersi Baker (Tenuipalpidae) development in sweet orange plants is influenced by previous mite infestation and the presence of shelters.

Citrus leprosis is the most important viral disease affecting citrus. The disease is caused predominantly by CiLV-C and is transmitted by Brevipalpus yothersi Baker mites. This study brings some insight into the colonization of B. yothersi in citrus [(Citrus × sinensis (L.) Osbeck (Rutaceae)] previously infested by viruliferous or non-viruliferous B. yothersi. It also assesses the putative role of shelters on the behavior of B. yothersi. Expression of PR1 and PR4 genes, markers of plant defense mechanisms, were evaluated by RT-qPCR to correlate the role of the plant hormonal changes during the tri-trophic virus-mite-plant interplay. A previous infestation with either non-viruliferous and viruliferous mites positively influenced oviposition and the number of adult individuals in the resulting populations. Mite populations were higher on branches that had received a previous mite infestation than branches that did not. There was an increase in the expression of PR4, a marker gene in the jasmonic acid (JA) pathway, in the treatment with non-viruliferous mites, indicating a response from the plant to their feeding. Conversely, an induced expression of PR1, a marker gene in the salicylic acid (SA) pathway, was observed mainly in the treatment with viruliferous mites, which suggests the activation of a plant response against the pathogen. The earlier mite infestation, as well as the presence of leprosis lesions and a gypsum mixture as artificial shelters, all fostered the growth of the B. yothersi populations after the second infestation, regardless of the presence or absence of CiLV-C. Furthermore, it is suggested that B. yothersi feeding actually induces the JA pathway in plants. At the same time, the CiLV-C represses the JA pathway and induces the SA pathway, which benefits the mite vector.

A tomato B-box protein regulates plant development and fruit quality through the interaction with PIF4, HY5, and RIN transcription factors.

During the last decade, knowledge about BBX proteins has greatly increased. Genome-wide studies identified the BBX gene family in several ornamental, industry, and food crops; however, reports regarding the role of these genes as regulators of agronomically important traits are scarce. Here, by phenotyping a knockout mutant, we performed a comprehensive functional characterization of the tomato locus Solyc12g089240, hereafter called SlBBX20. The data revealed the encoded protein as a positive regulator of light signaling affecting several physiological processes during the life span of plants. Through inhibition of PHYTOCHROME INTERACTING FACTOR 4 (SlPIF4)-auxin crosstalk, SlBBX20 regulates photomorphogenesis. Later in development, it controls the balance between cell division and expansion to guarantee correct vegetative and reproductive development. In fruits, SlBBX20 is transcriptionally induced by the master transcription factor RIPENING INHIBITOR (SlRIN) and, together with ELONGATED HYPOCOTYL 5 (SlHY5), up-regulates flavonoid biosynthetic genes. Finally, SlBBX20 promotes the accumulation of steroidal glycoalkaloids and attenuates Botrytis cinerea infection. This work clearly demonstrates that BBX proteins are multilayer regulators of plant physiology because they affect not only multiple processes during plant development but they also regulate other genes at the transcriptional and post-translational levels.

Maize hydroxycinnamic acids: unveiling their role in stress resilience and human health.

Maize production is pivotal in ensuring food security, particularly in developing countries. However, the crop encounters multiple challenges stemming from climatic changes that adversely affect its yield, including biotic and abiotic stresses during production and storage. A promising strategy for enhancing maize resilience to these challenges involves modulating its hydroxycinnamic acid amides (HCAAs) content. HCAAs are secondary metabolites present in plants that are essential in developmental processes, substantially contributing to defense mechanisms against environmental stressors, pests, and pathogens, and exhibiting beneficial effects on human health. This mini-review aims to provide a comprehensive overview of HCAAs in maize, including their biosynthesis, functions, distribution, and health potential applications.

Intraspecies competition among Salmonella enterica isolates in the lettuce leaf apoplast.

Multiple Salmonella enterica serovars and strains have been reported to be able to persist inside the foliar tissue of lettuce (Lactuca sativa L.), potentially resisting washing steps and reaching the consumer. Intraspecies variation of the bacterial pathogen and of the plant host can both significantly affect the outcome of foliar colonization. However, current understanding of the mechanisms underlying this phenomenon is still very limited. In this study, we evaluated the foliar fitness of 14 genetically barcoded S. enterica isolates from 10 different serovars, collected from plant and animal sources. The S. enterica isolates were vacuum-infiltrated individually or in pools into the leaves of three- to four-week-old lettuce plants. To estimate the survival capacity of individual isolates, we enumerated the bacterial populations at 0- and 10- days post-inoculation (DPI) and calculated their net growth. The competition of isolates in the lettuce apoplast was assessed through the determination of the relative abundance change of barcode counts of each isolate within pools during the 10 DPI experimental period. Isolates exhibiting varying apoplast fitness phenotypes were used to evaluate their capacity to grow in metabolites extracted from the lettuce apoplast and to elicit the reactive oxygen species burst immune response. Our study revealed that strains of S. enterica can substantially differ in their ability to survive and compete in a co-inhabited lettuce leaf apoplast. The differential foliar fitness observed among these S. enterica isolates might be explained, in part, by their ability to utilize nutrients available in the apoplast and to evade plant immune responses in this niche.

Plant bZIP Proteins: Potential use in Agriculture - A Review.

With global climate changes and the increased demand for food due to expected world population growth, genetic improvement programs have aimed at producing crops with increased yield and tolerance to environmental stresses, such as drought, salinity, and pathogens. On the other hand, genetic improvement programs via biotechnology require candidate genes that confer traits of interest to be incorporated into improved crops. In this regard, genes encoding transcription factors (TFs) can be promising since they are proteins that transcriptionally regulate the expression of target genes related to the most diverse roles in the plant, including defense against stresses. Among TFs, bZIP (basic leucine zipper) proteins regulate many developmental and physiological processes in the plant, such as seed formation, fruit ripening, nutrient assimilation, and defense response to abiotic and biotic stresses. In this review, we aim to highlight the main advances in the potential use of bZIP TFs in the genetic improvement of crops. We address this potential mainly regarding crop tolerance to stresses and other agricultural traits, such as increased yield and fruit features.

The chromosome-scale genome and the genetic resistance machinery against insect herbivores of the Mexican toloache, Datura stramonium.

Plant resistance refers to the heritable ability of plants to reduce damage caused by natural enemies, such as herbivores and pathogens, either through constitutive or induced traits like chemical compounds or trichomes. However, the genetic architecture-the number and genome location of genes that affect plant defense and the magnitude of their effects-of plant resistance to arthropod herbivores in natural populations remains poorly understood. In this study, we aimed to unveil the genetic architecture of plant resistance to insect herbivores in the annual herb Datura stramonium (Solanaceae) through quantitative trait loci mapping. We achieved this by assembling the species' genome and constructing a linkage map using an F2 progeny transplanted into natural habitats. Furthermore, we conducted differential gene expression analysis between undamaged and damaged plants caused by the primary folivore, Lema daturaphila larvae. Our genome assembly resulted in 6,109 scaffolds distributed across 12 haploid chromosomes. A single quantitative trait loci region on chromosome 3 was associated with plant resistance, spanning 0 to 5.17 cM. The explained variance by the quantitative trait loci was 8.44%. Our findings imply that the resistance mechanisms of D. stramonium are shaped by the complex interplay of multiple genes with minor effects. Protein-protein interaction networks involving genes within the quantitative trait loci region and overexpressed genes uncovered the key role of receptor-like cytoplasmic kinases in signaling and regulating tropane alkaloids and terpenoids, which serve as powerful chemical defenses against D. stramonium herbivores. The data generated in our study constitute important resources for delving into the evolution and ecology of secondary compounds mediating plant-insect interactions.

Arabidopsis thaliana phosphoinositide-specific phospholipase C 2 is required for Botrytis cinerea proliferation.

Phospholipase C (PLC) plays a key role in lipid signaling during plant development and stress responses. PLC activation is one of the earliest responses during pathogen perception. Arabidopsis thaliana contains seven PLC encoding genes (AtPLC1 to AtPLC7) and two pseudogenes (AtPLC8 and AtPLC9), being AtPLC2 the most abundant isoform with constitutive expression in all plant organs. PLC has been linked to plant defense signaling, in particular to the production of reactive oxygen species (ROS). Previously, we demonstrated that AtPLC2 is involved in ROS production via the NADPH oxidase isoforms RBOHD activation during stomata plant immunity. Here we studied the role of AtPLC2 on plant resistance against the necrotrophic fungus Botrytis cinerea, a broad host-range and serious agricultural pathogen. We show that the AtPLC2-silenced (amiR PLC2) or null mutant (plc2-1) plants developed smaller B. cinerea lesions. Moreover, plc2-1 showed less ROS production and an intensified SA-dependent signaling upon infection, indicating that B. cinerea uses AtPLC2-triggered responses for a successful proliferation. Therefore, AtPLC2 is a susceptibility (S) gene that facilitates B. cinerea infection and proliferation.

Network Analysis of Publicly Available RNA-seq Provides Insights into the Molecular Mechanisms of Plant Defense against Multiple Fungal Pathogens in Arabidopsis thaliana.

Fungal pathogens can have devastating effects on global crop production, leading to annual economic losses ranging from 10% to 23%. In light of climate change-related challenges, researchers anticipate an increase in fungal infections as a result of shifting environmental conditions. However, plants have developed intricate molecular mechanisms for effective defense against fungal attacks. Understanding these mechanisms is essential to the development of new strategies for protecting crops from multiple fungi threats. Public omics databases provide valuable resources for research on plant-pathogen interactions; however, integrating data from different studies can be challenging due to experimental variation. In this study, we aimed to identify the core genes that defend against the pathogenic fungi Colletotrichum higginsianum and Botrytis cinerea in Arabidopsis thaliana. Using a custom framework to control batch effects and construct Gene Co-expression Networks in publicly available RNA-seq dataset from infected A. thaliana plants, we successfully identified a gene module that was responsive to both pathogens. We also performed gene annotation to reveal the roles of previously unknown protein-coding genes in plant defenses against fungal infections. This research demonstrates the potential of publicly available RNA-seq data for identifying the core genes involved in defending against multiple fungal pathogens.

Carboxypeptidase inhibitors from Solanaceae as a new subclass of pathogenesis related peptide aiming biotechnological targets for plant defense.

Background: Plant protease inhibitors play a crucial role in inhibiting proteases produced by phytopathogens and exhibiting inhibitory effects on nematodes, fungi, and insects, making them promising candidates for crop protection. Specifically, carboxypeptidase inhibitors, a subset of proteinase inhibitors, have been extensively studied in potato and tomato of Solanaceae plant family. However, further research is needed to fully understand the functions and biotechnological potential of those inhibitors in plants. This work aimed to in silico characterize carboxypeptidase inhibitors from Solanaceae as potential antimicrobial and defense agents focused on biotechnological targets. Methods: The methodology employed involved search in UniProt, PDB, KNOTTIN, NCBI, and MEROPS databases for solanaceous carboxypeptidase inhibitors, phylogenetic relationships and conservation patterns analyzes using MEGA-X software and Clustal Omega/MView tools, physicochemical properties and antimicrobial potential prediction using ProtParam, ToxinPred, iAMPred, and APD3 tools, and structural features prediction using PSIPRED. Results and discussion: A systematic literature search was conducted to identify relevant studies on Solanaceae carboxypeptidase inhibitors and their activities against pathogens. The selected studies were reviewed and the main findings compiled. The characterization of Solanaceae carboxypeptidase inhibitors proposed for the first time the global sequence consensus motif CXXXCXXXXDCXXXXXCXXC, shedding light on carboxypeptidase inhibitors distribution, sequence variability, and conservation patterns. Phylogenetic analysis showed evolutionary relationships within the Solanaceae family, particularly in Capsicum, Nicotiana, and Solanum genera. Physicochemical characteristics of those peptides indicated their similarity to antimicrobial peptides. Predicted secondary structures exhibited variations, suggesting a broad spectrum of action, and studies had been demonstrated their activities against various pathogens. Conclusion: Carboxypeptidase inhibitors are being proposed here as a new subclass of PR-6 pathogenesis-related proteins, which will aid in a focused understanding of their functional roles in plant defense mechanisms. These findings confirm the Solanaceae carboxypeptidase inhibitors potential as defense agents and highlight opportunities for their biotechnological applications in pathogen control.

Responsiveness of Candidate Genes on CoPv01CDRK/PhgPv01CDRK Loci in Common Bean Challenged by Anthracnose and Angular Leaf Spot Pathogens.

Anthracnose (ANT) and angular leaf spot (ALS) are significant diseases in common bean, leading to considerable yield losses under specific environmental conditions. The California Dark Red Kidney (CDRK) bean cultivar is known for its resistance to multiple races of both pathogens. Previous studies have identified the CoPv01CDRK/PhgPv01CDRK resistance loci on chromosome Pv01. Here, we evaluated the expression levels of ten candidate genes near the CoPv01CDRK/PhgPv01CDRK loci and plant defense genes using quantitative real-time PCR in CDRK cultivar inoculated with races 73 of Colletotrichum lindemuthianum and 63-39 of Pseudocercospora griseola. Gene expression analysis revealed that the Phvul.001G246300 gene exhibited the most elevated levels, showing remarkable 7.8-fold and 8.5-fold increases for ANT and ALS, respectively. The Phvul.001G246300 gene encodes an abscisic acid (ABA) receptor with pyrabactin resistance, PYR1-like (PYL) protein, which plays a central role in the crosstalk between ABA and jasmonic acid responses. Interestingly, our results also showed that the other defense genes were initially activated. These findings provide critical insights into the molecular mechanisms underlying plant defense against these diseases and could contribute to the development of more effective disease management strategies in the future.

UHPLC-ESI-QTOF-MS/MS Profiling of Phytochemicals from Araticum Fruit (Annona crassiflora Mart.) and Its Antioxidant Activity.

Araticum is a native species of the Brazilian Cerrado with a high potential for exploitation. Several studies have stated that araticum is a rich source of phytochemicals with multifaceted biological actions. However, little information is available regarding the characterization of phytochemicals found in the pulp of this fruit. In this context, this study aimed to carry out a comprehensive characterization of phytochemicals present in the araticum pulp using ultra-high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (UHPLC-ESI-QTOF-MS/MS). The antioxidant potential of araticum pulp was also evaluated. UHPLC-ESI-QTOF-MS/MS profiling of the phytochemicals allowed for the identification and annotation of 139 phytochemicals, including organic acids, jasmonates, iridoids, phenolic compounds, alkaloids, annonaceous acetogenins, fatty acid derivatives, and other compounds. Among them, 116 compounds have been found for the first time in araticum pulp. Phenolic compounds and their derivatives represented about 59% of the phytochemicals identified in the extract. Moreover, araticum pulp showed high total phenolic compound content and antioxidant activity. The majority of identified phytochemicals have been associated with key roles in the plant's defense mechanisms against biotic and abiotic stress factors in the Cerrado environment. Furthermore, many of these phytochemicals found in the araticum pulp are already widely recognized for their beneficial effects on human health. Our findings showed that the araticum fruit contains different classes of phytochemicals that exert various biological activities, both in the plant itself and in humans.

Unlocking Cowpea's Defense Responses: Conserved Transcriptional Signatures in the Battle against CABMV and CPSMV Viruses.

Cowpea aphid-borne mosaic virus (CABMV) and Cowpea severe mosaic virus (CPSMV) threaten cowpea commercial production. This study aimed to analyze Conserved Transcriptional Signatures (CTS) in cowpea's genotypes that are resistant to these viruses. CTS covered up- (UR) or down-regulated (DR) cowpea transcripts in response to CABMV and CPSMV mechanical inoculations. The conservation of cowpea's UR defense response was primarily observed with the one hpi treatments, with decreased CTS representatives as time elapsed. This suggests that cowpea utilizes generic mechanisms during its early interaction with the studied viruses, and subsequently employs more specialized strategies for each viral agent. The potential action of the CTS-UR emphasizes the importance of redox balance, ethylene and jasmonic acid pathways. Additionally, the CTS-UR provides evidence for the involvement of R genes, PR proteins, and PRRs receptors-extensively investigated in combating bacterial and fungal pathogens-in the defense against viral inoculation. AP2-ERF, WRKY, and MYB transcription factors, as well as PIP aquaporins and MAPK cascades, also emerged as significant molecular players. The presented work represents the first study investigating conserved mechanisms in the cowpea defense response to viral inoculations, highlighting relevant processes for initial defense responses.

Interactions of Different Species of Phytophthora with Cacao Induce Genetic, Biochemical, and Morphological Plant Alterations.

Diseases associated with Phytophthora cause considerable losses in cocoa production worldwide. Analyzing genes, proteins, and metabolites involved in Theobroma cacao's interaction with Phytophthora species is essential to explaining the molecular aspects of plant defense. Through a systematic literature review, this study aims to identify reports of genes, proteins, metabolites, morphological characteristics, and molecular and physiological processes of T. cacao involved in its interaction with species of Phytophthora. After the searches, 35 papers were selected for the data extraction stage, according to pre-established inclusion and exclusion criteria. In these studies, 657 genes and 32 metabolites, among other elements (molecules and molecular processes), were found to be involved in the interaction. The integration of this information resulted in the following conclusions: the expression patterns of pattern recognition receptors (PRRs) and a possible gene-to-gene interaction participate in cocoa resistance to Phytophthora spp.; the expression pattern of genes that encode pathogenesis-related (PRs) proteins is different between resistant and susceptible genotypes; phenolic compounds play an important role in preformed defenses; and proline accumulation may be involved in cell wall integrity. Only one proteomics study of T. cacao-Phytophthora spp. was found, and some genes proposed via QTL analysis were confirmed in transcriptomic studies.

Plant hormesis: Revising of the concepts of biostimulation, elicitation and their application in a sustainable agricultural production.

Current research in basic and applied knowledge of plant science has aimed to unravel the role of the interaction between environmental factors and the genome in the physiology of plants to confer the ability to overcome challenges in a climate change scenario. Evidence shows that factors causing environmental stress (stressors), whether of biological, chemical, or physical origin, induce eustressing or distressing effects in plants depending on the dose. The latter suggests the induction of the "hormesis" phenomenon. Sustainable crop production requires a better understanding of hormesis, its basic concepts, and the input variables to make its management feasible. This implies that acknowledging hormesis in plant research could allow specifying beneficial effects to effectively manage environmental stressors according to cultivation goals. Several factors have been useful in this regard, which at low doses show beneficial eustressing effects (biostimulant/elicitor), while at higher doses, they show distressing toxic effects. These insights highlight biostimulants/elicitors as tools to be included in integrated crop management strategies for reaching sustainability in plant science and agricultural studies. In addition, compelling evidence on the inheritance of elicited traits in plants unfolds the possibility of implementing stressors as a tool in plant breeding.

Heavy metals and metalloids accumulation in common beans (Phaseolus vulgaris L.): A review.

Heavy metals (HMs) and metalloids (Ms) such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) represent serious environmental threats due to their wide abundance and high toxicity. Contamination of water and soils by HMs and Ms from natural or anthropogenic sources is of great concern in agricultural production due to their toxic effects on plants, adversely affecting food safety and plant growth. The uptake of HMs and Ms by Phaseolus vulgaris L. plants depends on several factors including soil properties such as pH, phosphate, and organic matter. High concentrations of HMs and Ms could be toxic to plants due to the increased generation of reactive oxygen species (ROS) such as (O2•-), (•OH), (H2O2), and (1O2), and oxidative stress due to an imbalance between ROS generation and antioxidant enzyme activity. To minimize the effects of ROS, plants have developed a complex defense mechanism based on the activity of antioxidant enzymes such as SOD, CAT, GPX, and phytohormones, especially salicylic acid (SA) that can reduce the toxicity of HMs and Ms. This review focuses on evaluating the accumulation and translocation of As, Cd, Hg, and Pb in Phaseolus vulgaris L. plants and on their possible effects on the growth of Phaseolus vulgaris L. in soil contaminated with these elements. The factors that affect the uptake of HMs and Ms by bean plants, and the defense mechanisms under oxidative stress caused by the presence of As, Cd, Hg, and Pb are also discussed. Furthermore, future research on mitigating HMs and Ms toxicity in Phaseolus vulgaris L. plants is highlighted.