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

Optimized submerged batch fermentation for metabolic switching in Streptomyces yanglinensis 3–10 providing platform for reveromycin A and B biosynthesis, engineering, and production

The cultivation system requires that the approach providing biomass for all types of metabolic analysis is of excellent quality and reliability. This study was conducted to enhance the efficiency and yield of antifungal substance (AFS) production in Streptomyces yanglinensis 3–10 by optimizing operation conditions of aeration, agitation, carbon source, and incubation time in a fermenter. Dissolved oxygen (DO) and pH were found to play significant roles in AFS production. The optimum pH for the production of AFS in S. yanglinensis 3–10 was found to be 6.5. As the AFS synthesis is generally thought to be an aerobic process, DO plays a significant role. The synthesis of bioactive compounds can vary depending on how DO affects growth rate. This study validates that the high growth rate and antifungal activity required a minimum DO concentration of approximately 20% saturation. The DO supply in a fermenter can be raised once agitation and aeration have been adjusted. Consequently, DO can stimulate the development of bacteria and enzyme production. A large shearing effect could result from the extreme agitation, harming the cell and deactivating its products. The highest inhibition zone diameter (IZD) was obtained with 3% starch, making starch a more efficient carbon source than glucose. Temperature is another important factor affecting AFS production. The needed fermentation time would increase and AFS production would be reduced by the too-low operating temperature. Furthermore, large-scale fermenters are challenging to manage at temperatures that are far below from room temperature. According to this research, 28°C is the ideal temperature for the fermentation of S. yanglinensis 3–10. The current study deals with the optimization of submerged batch fermentation involving the modification of operation conditions to effectively enhance the efficiency and yield of AFS production in S. yanglinensis 3–10

Wilting of bean plants from tobacco mosaic virus from smoking tobacco in Pakistan

Tobacco mosaic virus (TMV) was detected in one out of three samples of different commercial brands of cigarettes by RT-PCR. A PCR product between 650-680bp in size was observed on 1% agarose gel, which was confirmed as TMV through sequencing. Mechanical inoculation of sap from the PCR positive samples showed local lesions on bean (Phaseolus vulgaris) plants used as an indicator plant. In addition, symptoms of wilting were also observed in the bean plants. RT-PCR of extract from the inoculated bean plants reconfirmed the presence of TMV in bean plants. This study shows that TMV can be prevalent and has virulence in commercial tobacco (Nicotiana spp.). The wilting in bean plants upon mechanical inoculation of TMV was observed for the first time and can be reported as a new symptom of TMV infection in beans. This wilting associated to TMV opens the discussion for presence of different isolates of virus, symptomatic expression on differential hosts and methods of mechanical inoculation

Conventional and Molecular Techniques from Simple Breeding to Speed Breeding in Crop Plants: Recent Advances and Future Outlook

In most crop breeding programs, the rate of yield increment is insufficient to cope with the increased food demand caused by a rapidly expanding global population. In plant breeding, the development of improved crop varieties is limited by the very long crop duration. Given the many phases of crossing, selection, and testing involved in the production of new plant varieties, it can take one or two decades to create a new cultivar. One possible way of alleviating food scarcity problems and increasing food security is to develop improved plant varieties rapidly. Traditional farming methods practiced since quite some time have decreased the genetic variability of crops. To improve agronomic traits associated with yield, quality, and resistance to biotic and abiotic stresses in crop plants, several conventional and molecular approaches have been used, including genetic selection, mutagenic breeding, somaclonal variations, whole-genome sequence-based approaches, physical maps, and functional genomic tools. However, recent advances in genome editing technology using programmable nucleases, clustered regularly interspaced short palindromic repeats (CRISPR), and CRISPR-associated (Cas) proteins have opened the door to a new plant breeding era. Therefore, to increase the efficiency of crop breeding, plant breeders and researchers around the world are using novel strategies such as speed breeding, genome editing tools, and high-throughput phenotyping. In this review, we summarize recent findings on several aspects of crop breeding to describe the evolution of plant breeding practices, from traditional to modern speed breeding combined with genome editing tools, which aim to produce crop generations with desired traits annually

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

ChileRhizoctonia 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