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Crop production is the basis of agriculture in Kazakhstan. Soils in Kazakhstan suffer from molybdenum deficiency. Molybdenum deficiency in plants is characterized by the stunted growth, poor seed setting, fruit deformation and reduced plant resistance to diseases. Molybdenum catalyzes key steps in the metabolism of nitrogen, carbon and sulfur. It promotes the biosynthesis of the phytohormones of abscisic acid and indole-3-butyric acid. An increase in molybdenum concentration leads to an increase in aldehyde oxidase activity. Aldehyde oxidase generates hydrogen peroxide during viral infection; hydrogen peroxide triggers a hypersensitive response, strengthens cell walls and prevents the spread of viral infection. Molybdenum is biologically inactive until a special complex called molybdenum cofactor is formed. For the formation of the latter it is necessary for molybdenum to be in the state of molybdate anion. There are five known plant molybdoenzymes: aldehyde oxidase, sulfite oxidase, nitrate reductase, xanthine dehydrogenase and mitochondrial amidoxime resuctase. The aim of this work is to find the optimal concentration of molybdenum for aldehyde oxidase activation. The objectives of the conducted experiment are: - to apply an efficient and cost-effective method to replenish molybdenum deficiency in the experimental plant; - to demonstrate the effect of molybdenum on the development of virus infection of the infected plant. As a result, it was proved that with the increase of concentration from 0.1 mM to 1 mM, the activity of aldehyde oxidase increases, which contributes to the increase of seed germination. The optimal concentration for seed germination is 1 Mm molybdenum concentration. As the concentration of molybdenum increases, the resistance of adult plants to virus infection also increases. Thus, 1 mМ molybdenum concentration is optimal for seed germination and resistance to virus infection. [ABSTRACT FROM AUTHOR]

The main aim of this work was to develop a time-saving and cost-effective purification method of infectious plant viral nanoparticles. Virions of Tomato bushy stunt virus (TBSV), which is a member of Tombusvirus genus, were purified by one-step Biogel HT Hydroxyapatite (HA) column chromatography. Extracts from Nicotiana benthamiana plants infected with TBSV were directly loaded onto the HA column and eluted by 10 mM sodium phosphate buffer (pH 6.8). A specificity of virions has been confirmed by immunoblotting and electron microscopy. Homogeneity of virions was tested by SDS-PAGE, where only 41 kDa polypeptide bands referring to the capsid protein of TBSV were detected by Coomassie staining. The biological infectious activity of a purified material was demonstrated by observing TBSV-specific symptoms observed in N. benthamiana plants at 7-10 days of post-inoculation (dpi). Moreover, purified virions were used for immunization of the BALb/c mouse to raise primary antibodies against the TBSV virus. Our results show that in low concentrations of sodium phosphate buffer total proteins extracted from infected plants adsorb to HA sorbent, while viral particles do not adsorb to the HA matrix and flow throw column due to Ca2+ ions implicated in TBSV virions' structure. This highly effective and simple virus purification protocol can also be used for the isolation of other plant virions. [ABSTRACT FROM AUTHOR]

The advent of unique technologies of the developing Solar Energy (SE), actual energy, faces economic and environmental problems. The main obstacle to the widespread use of SE is the low value of the average annual efficiency of known solar installations. In a sharply continental climate, they are exploited only in the warm season, about 6-7 months. Known combined systems, where additional conventional water heaters duplicate the operation of solar units, require additional costs for energy carriers. These disadvantages are not offered by the integrated system of SE use. In the article, the system was studied using the example of a cattle-breeding farm. The new system performs these functions; it recycles heat, organizes their movement and accumulation, and smooths out the uneven SE. The main components of the system are: Solar Power Plant (SPP), milk cooler, climate unit, Heat Pump (HP), the battery heat, automatic control system, and device heating and hot water. The main goal, i.e. lower cost of the energy produced and the elimination of the uneven SE, compared to the known SPP, is achieved through the flow of energy from the sources mentioned above. [ABSTRACT FROM AUTHOR]

RNA interference (RNAi) plays multiple biological roles in eukaryotic organisms to regulate gene expression. RNAi also operates as a conserved adaptive molecular immune mechanism against invading viruses. The antiviral RNAi pathway is initiated with the generation of virus-derived short-interfering RNAs (siRNAs) that are used for subsequent sequence-specific recognition and degradation of the cognate viral RNA molecules. As an efficient counter-defensive strategy, most plant viruses evolved the ability to encode specific proteins capable of interfering with RNAi, and this process is commonly known as RNA silencing suppression. Virus-encoded suppressors of RNAi (VSRs) operate at different steps in the RNAi pathway and display distinct biochemical properties that enable these proteins to efficiently interfere with the host-defense system. Tombusvirus-encoded P19 is an important pathogenicity factor, required for symptom development and elicitation of a hypersensitive response in a host-dependent manner. Protein plays a crucial role of TBSV P19 in protecting viral RNA during systemic infection on Nicotiana benthamiana. The X-ray crystallographic studies conducted by two independent groups revealed the existence of a P19-siRNA complex; a conformation whereby caliper tryptophan residues on two subunits of P19 dimers measure and bind 21-nt siRNA duplexes. These structural studies provided the first details on the possible molecular mechanism of any viral suppressor to block RNAi. The association between P19 and siRNAs was also shown to occur in infected plants These and related studies revealed that in general the ability of P19 to efficiently sequester siRNAs influences symptom severity, however this is not a strict correlation in all hosts.The current working model is that during TBSV infection of plants, P19 appropriates abundantly circulating Tombusvirus-derived siRNAs thereby rendering these unavailable to program RISC, to prevent degradation of viral RNA and thus permit maintenance of viral RNA for systemic invasion. Evidence in support of this notion is that infection of N. benthamiana with P19-deficient tombusviral mutants was associated with the assembly of a discrete, high molecular weight RISC-like complex, which contains virus-derived siRNAs and exhibits specific ribonuclease activity.

Among the three active aldehyde oxidases in Arabidopsis thaliana leaves (AAO1-3), AAO3, which catalyzes the oxidation of abscisic-aldehyde to abscisic-acid, was shown recently to function as a reactive aldehyde detoxifier. Notably, aao2KO mutants exhibited less senescence symptoms and lower aldehyde accumulation, such as acrolein, benzaldehyde, and 4-hydroxyl-2-nonenal (HNE) than in wild-type leaves exposed to UV-C or Rose-Bengal. The effect of AAO2 expression absence on aldehyde detoxification by AAO3 and/or AAO1 was studied by comparing the response of wild-type plants to the response of single-functioning aao1 mutant (aao1S), aao2KO mutants, and single-functioning aao3 mutants (aao3Ss). Notably, aao3Ss exhibited similar aldehyde accumulation and chlorophyll content to aao2KO treated with UV-C or Rose-Bengal. In contrast, wild-type and aao1S exhibited higher aldehyde accumulation that resulted in lower remaining chlorophyll than in aao2KO leaves, indicating that the absence of active AAO2 enhanced AAO3 detoxification activity in aao2KO mutants. In support of this notion, employing abscisic-aldehyde as a specific substrate marker for AAO3 activity revealed enhanced AAO3 activity in aao2KO and aao3Ss leaves compared to wild-type treated with UV-C or Rose-Bengal. The similar abscisic-acid level accumulated in leaves of unstressed or stressed genotypes indicates that aldehyde detoxification by AAO3 is the cause for better stress resistance in aao2KO mutants. Employing the sulfuration process (known to activate aldehyde oxidases) in wild-type, aao2KO, and molybdenum-cofactor sulfurase (aba3-1) mutant plants revealed that the active AAO2 in WT employs sulfuration processes essential for AAO3 activity level, resulting in the lower AAO3 activity in WT than AAO3 activity in aao2KO., (© 2024 The Author(s). The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.)

The Tomato bushy stunt virus (TBSV)-encoded p19 protein (P19) is widely used as a robust tool to suppress RNA interference (RNAi) in various model organisms. P19 dimers appropriate 21-nucleotide (nt) duplex short interfering RNAs (siRNAs) generated by Dicer presumably to prevent programming of the RNA-induced silencing complex (RISC). In the context of virus infection, this model predicts that P19 mutants compromised for siRNA binding cannot prevent RISC-mediated degradation of TBSV RNA and thus reduce viral pathogenicity. To test this, we used P19/43 (R-->W), which is less pathogenic than wild-type P19 (wtP19), and P19/75-78 (RR-->GG), with pathogenicity properties (i.e., viral spread and symptom induction) comparable to those of a P19-null mutant. We demonstrate that P19/43 still suppresses RNAi-mediated viral RNA degradation in infected Nicotiana benthamiana, while P19/75-78 is unable to prevent this clearance of viral RNA, leading to an irreversible recovery phenotype. Gel filtration and immunoprecipitation assays show that at the onset of the infection, wtP19, P19/43, and P19/75-78 readily accumulate, and they form dimers. The wtP19 is stably associated with duplex approximately 21-nt TBSV siRNAs, while P19/75-78 does not bind these molecules, and the electrostatic interaction of P19/43 with siRNAs is perturbed for approximately 21-nt duplexes but not for longer siRNAs. This is the first clear demonstration of a direct correlation between a novel structurally orchestrated siRNA binding of an RNAi suppressor and its roles in viral pathogenesis. The findings should be particularly valuable for the RNAi field in general because the P19 mutants enable precise determination of siRNA appropriation effects.