Rice false smut pathogen: implications for mycotoxin contamination, current status, and future perspectives.

Rice serves as a staple food across various continents worldwide. The rice plant faces significant threats from a range of fungal, bacterial, and viral pathogens. Among these, rice false smut disease (RFS) caused by Villosiclava virens is one of the devastating diseases in rice fields. This disease is widespread in major rice-growing regions such as China, Pakistan, Bangladesh, India, and others, leading to significant losses in rice plantations. Various toxins are produced during the infection of this disease in rice plants, impacting the fertilization process as well. This review paper lightens the disease cycle, plant immunity, and infection process during RFS. Mycotoxin production in RFS affects rice plants in multiple ways, although the exact phenomena are still unknown.

The MAP Kinase PvMK1 Regulates Hyphal Development, Autophagy, and Pathogenesis in the Bayberry Twig Blight Fungus Pestalotiopsis versicolor.

Bayberry twig blight caused by the ascomycete fungus Pestalotiopsis versicolor is a devastating disease threatening worldwide bayberry production. However, the molecular basis underlying the pathogenesis of P. versicolor is largely unknown. Here, we identified and functionally characterized the MAP kinase PvMk1 in P. versicolor through genetic and cellular biochemical approaches. Our analysis reveals a central role of PvMk1 in regulating P. versicolor virulence on bayberry. We demonstrate that PvMk1 is involved in hyphal development, conidiation, melanin biosynthesis, and cell wall stress responses. Notably, PvMk1 regulates P. versicolor autophagy and is essential for hyphal growth under nitrogen-depleting conditions. These findings suggest the multifaceted role of PvMk1 in regulating P. versicolor development and virulence. More remarkably, this evidence of virulence-involved cellular processes regulated by PvMk1 has paved a fundamental way for further understanding the impact of P. versicolor pathogenesis on bayberry.

An explanation of the mystifying bakanae disease narrative for tomorrow's rice.

Rice production is severely hampered by the bakanae disease (Fusarium fujikuroi), formerly recognized as Fusarium moniliforme. F. moniliforme was called the F. fujikuroi species complex (FFSC) because it was later discovered that it had some separate species. The FFSC's constituents are also well recognized for producing phytohormones, which include auxins, cytokinin, and gibberellins (GAs). The normal symptoms of bakanae disease in rice are exacerbated by GAs. The members of the FFSC are responsible for the production of fumonisin (FUM), fusarins, fusaric acid, moniliformin, and beauvericin. These are harmful to both human and animal health. This disease is common around the world and causes significant yield losses. Numerous secondary metabolites, including the plant hormone gibberellin, which causes classic bakanae symptoms, are produced by F. fujikuroi. The strategies for managing bakanae, including the utilization of host resistance, chemical compounds, biocontrol agents, natural goods, and physical approaches, have been reviewed in this study. Bakanae disease is still not entirely preventable, despite the adoption of many different tactics that have been used to manage it. The benefits and drawbacks of these diverse approaches are discussed by the authors. The mechanisms of action of the main fungicides as well as the strategies for resistance to them are outlined. The information compiled in this study will contribute to a better understanding of the bakanae disease and the development of a more effective management plan for it.

Harnessing fungal bio-electricity: a promising path to a cleaner environment.

Integrating fungi into fuel cell systems presents a promising opportunity to address environmental pollution while simultaneously generating energy. This review explores the innovative concept of constructing wetlands as fuel cells for pollutant degradation, offering a practical and eco-friendly solution to pollution challenges. Fungi possess unique capabilities in producing power, fuel, and electricity through metabolic processes, drawing significant interest for applications in remediation and degradation. Limited data exist on fungi's ability to generate electricity during catalytic reactions involving various enzymes, especially while remediating pollutants. Certain species, such as Trametes versicolor, Ganoderma lucidum, Galactomyces reessii, Aspergillus spp., Kluyveromyce smarxianus, and Hansenula anomala, have been reported to generate electricity at 1200 mW/m3, 207 mW/m2, 1,163 mW/m3, 438 mW/m3, 850,000 mW/m3, and 2,900 mW/m3, respectively. Despite the eco-friendly potential compared to conventional methods, fungi's role remains largely unexplored. This review delves into fungi's exceptional potential as fuel cell catalysts, serving as anodic or cathodic agents to mitigate land, air, and water pollutants while simultaneously producing fuel and power. Applications cover a wide range of tasks, and the innovative concept of wetlands designed as fuel cells for pollutant degradation is discussed. Cost-effectiveness may vary depending on specific contexts and applications. Fungal fuel cells (FFCs) offer a versatile and innovative solution to global challenges, addressing the increasing demand for alternative bioenergy production amid population growth and expanding industrial activities. The mechanistic approach of fungal enzymes via microbial combinations and electrochemical fungal systems facilitates the oxidation of organic substrates, oxygen reduction, and ion exchange membrane orchestration of essential reactions. Fungal laccase plays a crucial role in pollutant removal and monitoring environmental contaminants. Fungal consortiums show remarkable potential in fine-tuning FFC performance, impacting both power generation and pollutant degradation. Beyond energy generation, fungal cells effectively remove pollutants. Overall, FFCs present a promising avenue to address energy needs and mitigate pollutants simultaneously.

Root rot a silent alfalfa killer in China: Distribution, fungal, and oomycete pathogens, impact of climatic factors and its management.

Alfalfa plays a significant role in the pasture ecosystems of China's north, northeast, and northwest regions. It is an excellent forage for livestock, improves soil structure, prevents soil erosion, and has ecological benefits. Presently root rot is a significant threat to the alfalfa productivity because of the survival of the pathogens as soil-borne and because of lack of microbial competition in the impoverished nutrient-deficient soils and resistant cultivars. Furthermore, these regions' extreme ecological and environmental conditions predispose alfalfa to root rot. Moisture and temperature, in particular, have a considerable impact on the severity of root rot. Pathogens such as Fusarium spp. and Rhizoctonia solani are predominant, frequently isolated, and of major concern. These pathogens work together as disease complexes, so finding a host genotype resistant to disease complexes is challenging. Approaches to root rot control in these regions include mostly fungicides treatments and cultural practices and very few reports on the usage of biological control agents. As seed treatment, fungicides such as carbendazim are frequently used to combat root rot; however, resistance to fungicides has arisen. However, breeding and transgenic approaches could be more efficient and sustainable long-term control strategies, especially if resistance to disease complexes may be identified. Yet, research in China is mainly limited to field investigation of root rot and disease resistance evaluation. In this review, we describe climatic conditions of pastoral regions and the role of alfalfa therein and challenges of root rot, the distribution of root rot in the world and China, and the impact of root rot pathogens on alfalfa in particular R. solani and Fusarium spp., effects of environmental factors on root rot and summarize to date disease management approach.

Trichoderma spp. Genes Involved in the Biocontrol Activity Against Rhizoctonia solani.

Rhizoctonia solani is a pathogen that causes considerable harm to plants worldwide. In the absence of hosts, R. solani survives in the soil by forming sclerotia, and management methods, such as cultivar breeding, crop rotations, and fungicide sprays, are insufficient and/or inefficient in controlling R. solani. One of the most challenging problems facing agriculture in the twenty-first century besides with the impact of global warming. Environmentally friendly techniques of crop production and improved agricultural practices are essential for long-term food security. Trichoderma spp. could serve as an excellent example of a model fungus to enhance crop productivity in a sustainable way. Among biocontrol mechanisms, mycoparasitism, competition, and antibiosis are the fundamental mechanisms by which Trichoderma spp. defend against R. solani, thereby preventing or obstructing its proliferation. Additionally, Trichoderma spp. induce a mixed induced systemic resistance (ISR) or systemic acquired resistance (SAR) in plants against R. solani, known as Trichoderma-ISR. Stimulation of every biocontrol mechanism involves Trichoderma spp. genes responsible for encoding secondary metabolites, siderophores, signaling molecules, enzymes for cell wall degradation, and plant growth regulators. Rhizoctonia solani biological control through genes of Trichoderma spp. is summarized in this paper. It also gives information on the Trichoderma-ISR in plants against R. solani. Nonetheless, fast-paced current research on Trichoderma spp. is required to properly utilize their true potential against diseases caused by R. solani.

Genome Engineering Technology for Durable Disease Resistance: Recent Progress and Future Outlooks for Sustainable Agriculture.

Crop production worldwide is under pressure from multiple factors, including reductions in available arable land and sources of water, along with the emergence of new pathogens and development of resistance in pre-existing pathogens. In addition, the ever-growing world population has increased the demand for food, which is predicted to increase by more than 100% by 2050. To meet these needs, different techniques have been deployed to produce new cultivars with novel heritable mutations. Although traditional breeding continues to play a vital role in crop improvement, it typically involves long and laborious artificial planting over multiple generations. Recently, the application of innovative genome engineering techniques, particularly CRISPR-Cas9-based systems, has opened up new avenues that offer the prospects of sustainable farming in the modern agricultural industry. In addition, the emergence of novel editing systems has enabled the development of transgene-free non-genetically modified plants, which represent a suitable option for improving desired traits in a range of crop plants. To date, a number of disease-resistant crops have been produced using gene-editing tools, which can make a significant contribution to overcoming disease-related problems. Not only does this directly minimize yield losses but also reduces the reliance on pesticide application, thereby enhancing crop productivity that can meet the globally increasing demand for food. In this review, we describe recent progress in genome engineering techniques, particularly CRISPR-Cas9 systems, in development of disease-resistant crop plants. In addition, we describe the role of CRISPR-Cas9-mediated genome editing in sustainable agriculture.

Advances, limitations, and prospects of biosensing technology for detecting phytopathogenic bacteria.

Phytopathogenic bacteria cause severe economic losses in agricultural production worldwide. The spread rates, severity, and emerging plant bacterial diseases have become serious threat to the sustainability of food sources and the fruit industry. Detection and diagnosis of plant diseases are imperative in order to manage plant diseases in field conditions, greenhouses, and food storage conditions as well as to maximize agricultural productivity and sustainability. To date, various techniques including, serological, observation-based, and molecular methods have been employed for plant disease detection. These methods are sensitive and specific for genetic identification of bacteria. However, these methods are specific for genetic identification of bacteria. Currently, the innovative biosensor-based disease detection technique is an attractive and promising alternative. A biosensor system involves biological recognition and transducer active receptors based on sensors used in plant-bacteria diagnosis. This system has been broadly used for the rapid diagnosis of plant bacterial pathogens. In the present review, we have discussed the conventional methods of bacterial-disease detection, however, the present review mainly focuses on the applications of different biosensor-based techniques along with point-of-care (POC), robotics, and cell phone-based systems. In addition, we have also discussed the challenges and limitations of these techniques.

Synergistic Effects of Bacillus amyloliquefaciens SDTB009 and Difenoconazole on Fusarium Wilt of Tomato.

Fusarium wilt is a destructive and widespread disease of tomatoes in China, and currently, there are no effective and environmentally friendly control measures. Combining biological control agents with fungicides has become an executable method for disease control. Here, Bacillus amyloliquefaciens SDTB009 showed excellent in vitro antagonistic activity against Fusarium oxysporum and tolerance to high concentrations of difenoconazole (200 mg/liter) in vitro. The combination of SDTB009 and difenoconazole exhibited more effectiveness in mycelial growth inhibition than either treatment alone. Compared with that in the SDTB009 bulk solution in vitro (5.22 g/liter), surfactin titer reached 7.15 g/liter in the 100 mg/liter of difenoconazole-containing medium. Interestingly, the upregulation of 20 genes in the surfactin biosynthesis pathway from 2-fold to 4-fold was observed, explaining the synergistic effect. The SDTB009 combined with varying concentrations of difenoconazole (60, 120, and 150 g a.i./ha) showed a synergistic effect in two consecutive years of field trials. These results show that the integration of difenoconazole with the biocontrol agent B. amyloliquefaciens SDTB009 synergistically increases the control efficacy of the fungicide against tomato Fusarium wilt.

Global distribution, traditional and modern detection, diagnostic, and management approaches of Rhizoctonia solani associated with legume crops.

Sustainable development relies heavily on a food system that is both safe and secure. Several approaches may lead to sustainability and food safety. An increase in the cultivation of legume crops is one of the approaches for enhancing agricultural viability and ensuring adequate food supply. Legumes may increase daily intake of fiber, folate, and protein as substitutes for meat and dairy. They are also crucial in various intercropping systems worldwide. However, legume production has been hampered by Rhizoctonia solani due to its destructive lifestyle. R. solani causes blights, damping off, and rotting diseases in legume crops. Our knowledge of the global distribution of R. solani associated with legume crops (alfalfa, soybean, chickpea, pea, lentil, common bean, and peanut), detection, diagnosis, and management of legume crops diseases caused by R. solani is limited. Traditional approaches rely on the incubation of R. solani, visual examination of symptoms on host legume crops, and microscopy identification. However, these approaches are time-consuming, require technical expertise, fail to detect a minimal amount of inoculum, and are unreliable. Biochemical and molecular-based approaches have been used with great success recently because of their excellent sensitivity and specificity. Along with conventional PCR, nested PCR, multiplex PCR, real-time PCR, magnetic-capture hybridization PCR, and loop-mediated isothermal amplification have been widely used to detect and diagnose R. solani. In the future, Next-generation sequencing will likely be used to a greater extent to detect R. solani. This review outlines global distribution, survival, infection and disease cycle, traditional, biochemical, molecular, and next-generation sequencing detection and diagnostic approaches, and an overview of the resistant resources and other management strategies to cope with R. solani.

Diversity and Taxonomic Distribution of Endophytic Bacterial Community in the Rice Plant and Its Prospective.

Endophytic bacterial communities are beneficial communities for host plants that exist inside the surfaces of plant tissues, and their application improves plant growth. They benefit directly from the host plant by enhancing the nutrient amount of the plant's intake and influencing the phytohormones, which are responsible for growth promotion and stress. Endophytic bacteria play an important role in plant-growth promotion (PGP) by regulating the indirect mechanism targeting pest and pathogens through hydrolytic enzymes, antibiotics, biocontrol potential, and nutrient restriction for pathogens. To attain these benefits, firstly bacterial communities must be colonized by plant tissues. The nature of colonization can be achieved by using a set of traits, including attachment behavior and motility speed, degradation of plant polymers, and plant defense evasion. The diversity of bacterial endophytes colonization depends on various factors, such as plants' relationship with environmental factors. Generally, each endophytic bacteria has a wide host range, and they are used as bio-inoculants in the form of synthetic applications for sustainable agriculture systems and to protect the environment from chemical hazards. This review discusses and explores the taxonomic distribution of endophytic bacteria associated with different genotypes of rice plants and their origin, movement, and mechanism of PGP. In addition, this review accentuates compressive meta data of endophytic bacteria communities associated with different genotypes of rice plants, retrieves their plant-growth-promoting properties and their antagonism against plant pathogens, and discusses the indication of endophytic bacterial flora in rice plant tissues using various methods. The future direction deepens the study of novel endophytic bacterial communities and their identification from rice plants through innovative techniques and their application for sustainable agriculture systems.

A Novel Hexose Transporter ChHxt6 Is Required for Hexose Uptake and Virulence in Colletotrichum higginsianum.

Colletotrichum higginsianum is an important hemibiotrophic plant pathogen that causes crucifer anthracnose worldwide. To date, some hexose transporters have been identified in fungi. However, the functions of hexose transporters in virulence are not clear in hemibiotrophic phytopathogens. In this study, we identified and characterized a new hexose transporter gene named ChHxt6 from a T-DNA insertion pathogenicity-deficient mutant G256 in C. higginsianum. Expression profiling analysis revealed that six ChHxt genes, ChHxt1 to ChHxt6, exhibited specific expression patterns in different infection phases of C. higginsianum. The ChHxt1 to ChHxt6 were separately deleted using the principle of homologous recombination. ChHxt1 to ChHxt6 deletion mutants grew normally on PDA plates, but only the virulence of ChHxt4 and ChHxt6 deletion mutants was reduced. ChHxt4 was required for fungal infection in both biotrophic and necrotrophic stages, while ChHxt6 was important for formation of necrotrophic hyphae during infection. In addition, ChHxts were functional in uptake of different hexoses, but only ChHxt6-expressing cells could grow on all five hexoses, indicating that the ChHxt6 was a central hexose transporter and crucial for hexose uptake. Site-directed mutation of T169S and P221L positions revealed that these two positions were necessary for hexose transport, whereas only the mutation Thr169 caused reduced virulence and defect in formation of necrotrophic hyphae. Taken together, ChHxt6 might regulate fungal virulence by modulating the utilization of hexose.

Research advances and applications of biosensing technology for the diagnosis of pathogens in sustainable agriculture.

Plant diseases significantly impact the global economy, and plant pathogenic microorganisms such as nematodes, viruses, bacteria, fungi, and viroids may be the etiology for most infectious diseases. In agriculture, the development of disease-free plants is an important strategy for the determination of the survival and productivity of plants in the field. This article reviews biosensor methods of disease detection that have been used effectively in other fields, and these methods could possibly transform the production methods of the agricultural industry. The precise identification of plant pathogens assists in the assessment of effective management steps for minimization of production loss. The new plant pathogen detection methods include evaluation of signs of disease, detection of cultured organisms, or direct examination of contaminated tissues through molecular and serological techniques. Laboratory-based approaches are costly and time-consuming and require specialized skills. The conclusions of this review also indicate that there is an urgent need for the establishment of a reliable, fast, accurate, responsive, and cost-effective testing method for the detection of field plants at early stages of growth. We also summarized new emerging biosensor technologies, including isothermal amplification, detection of nanomaterials, paper-based techniques, robotics, and lab-on-a-chip analytical devices. However, these constitute novelty in the research and development of approaches for the early diagnosis of pathogens in sustainable agriculture.