Agrobacterium fabrum gene atu1420 regulates the pathogenicity by affecting the degradation of growth- and virulence-associated phenols.

Agrobacterium fabrum is a phytopathogen that causes the crown gall disease. Some plant-derived molecules, e.g. phenols, directly affect A. fabrum-plant interactions. Here, we characterize a phenolic catabolism-related gene, atu1420, that affects the pathogenicity of A. fabrum. Atu1420 is predicted to be an O-demethylase with high structural homology to Sphingomonas paucimobilis LigM. The HPLC-UV analysis showed that atu1420 affected the degradation of acetosyringone (AS). The deletion of atu1420 gene significantly enhanced the AS-induced virulence (vir) gene expression. atu1420 was shown to relieve the inhibitory effect of vanillic acid on the AS-induced vir gene expression and the growth of A. fabrum. The expression of atu1420 and the degradation of AS in A. fabrum C58 was up-regulated by the addition of indole acetic acid (IAA). The inhibitory effect of IAA on the AS-induced vir gene expression was partially relieved by the deletion of atu1420 gene, indicating that accelerating the degradation of AS is one of the ways that IAA inhibits vir genes induction. Furthermore, atu1420 mutant produced more pronounced tumors on kalanchoe leaves than the wild-type strain. These findings reveal the role of atu1420 in A. fabrum-host interactions and will broaden our understanding of the regulatory network of the interactions.

Vivax Malaria and the Potential Role of the Subtelomeric Multigene vir Superfamily.

Vivax malaria, caused by Plasmodium vivax, remains a public health concern in Central and Southeast Asia and South America, with more than two billion people at risk of infection. Compared to Plasmodium falciparum, P. vivax is considered a benign infection. However, in recent decades, incidences of severe vivax malaria have been confirmed. The P. falciparum erythrocyte membrane protein 1 family encoded by var genes is known as a mediator of severe falciparum malaria by cytoadherence property. Correspondingly, the vir multigene superfamily has been identified as the largest multigene family in P. vivax and is implicated in cytoadherence to endothelial cells and immune response activation. In this review, the functions of vir genes are reviewed in the context of their potential roles in severe vivax malaria.

Evaluation of Wheat Resistance to Snow Mold Caused by Microdochium nivale (Fr) Samuels and I.C. Hallett under Abiotic Stress Influence in the Central Non-Black Earth Region of Russia.

Microdochium nivale is one of the most harmful fungal diseases, causing colossal yield losses and deteriorating grain quality. Wheat genotypes from the world collection of the N.I. Vavilov Institute (VIR) were evaluated for fifty years to investigate their resistance to biotic stress factors (M. nivale). Between 350 to 1085 of winter wheat genotypes were investigated annually. Ten out of fifty years were identified as rot epiphytotics (1978, 1986, 1989, 1990, 1993, 1998, 2001, 2003, 2005 and 2021). The wheat collection was investigated by following the VIR methodological requirements and CMEA unified classification of Triticum aestivum L. The field investigations were carried out in the early spring during fixed-route observations and data collection was included on the spread and development degree of the disease, followed by microbiological and microscopic pathogen identifications. The observations revealed that the primary reason for pink snow mold to infect the wheat crops was abiotic stress factors, such as thawed soil covered in snow that increased the soil temperature by 1.0-4.6 °C above normal. Under these conditions, the plants kept growing, quickly exhausting their carbohydrate and protein resources, thus weakening their immune systems, which made them an easy target for different infections, mainly cryophilic fungi, predominantly Microdochium nivale in the Moscow region. In some years, the joint effect of abiotic and biotic stresses caused crop failure, warranting the replanting of the spring wheat. The investigated wheat genotypes exhibited variable resistance to pink snow mold. The genotypes Mironovskaya 808 (k-43920) from Ukraine;l Nemchinovskaya 846 (k-56861), from Russia; Novobanatka (k-51761) from Yugoslavia; Liwilla (k-57580) from Poland; Zdar (UH 7050) from the Czech Republic; Maris Plowman (k-57944) from the United Kingdom; Pokal (k-56827) from Austria; Hvede Sarah (k-56289) from Denmark; Moldova 83 (k-59750) from Romania; Compal (k-57585) from Germany; Linna (k-45889) from Finland and Kehra (k-34228) from Estonia determined the sources, stability and tolerance to be used in advanced breeding programs.

The Biological Traumatization of Crops Due to the Enzyme Stage of Enzyme-Mycotic Seed Depletion.

In the light of Vavilov's Law, grain traumatization in the standing crop of wheat and other crops due to the enzyme stage of enzyme-mycotic seed depletion (EMSD) was confirmed, the parameters of open and hidden harmfulness were detected, and a scale of plant resistance to such traumatization was developed. The current study demonstrates that pathogen contamination in grains occurs before harvesting and its degree is determined by favorable humidity and temperature conditions and by the open and hidden grain traumatization due to the enzyme stage of EMSD, i.e., the grain's hydrolytic enzymes providing a growth substrate for a fungal spread that is later substituted by pathogen enzymes leading to grain spoiling and self-warming. The most common technique to preserve grain quality is to support a moisture level that prevents further spreading of the fungi. The grains that are contaminated with very low temperature and humidity levels facilitate the germinability and high quality of the grain. The new ways to withstand EMSD should, first of all, include a selection of activities. Using biological, biochemical and physical (X-ray) methods, genetic sources of resistance towards EMSD were found in the VIR world collection that is recommended for further selection. These sources have become a basis for the varieties, such as Moskovskaya 39, Ilot (winter wheat), Gremme and Gremme 2U (hulless spelt), Alcoran (winter spelt) and Kanysh (spring wheat).

The Evaluation of Winter Wheat Adaptation to Climate Change in the Central Non-Black Region of Russia: Study of the Gene Pool Resistance of Wheat from the N.I. Vavilov Institute of Plant Industry (VIR) World Collection to Abiotic Stress Factors.

The paper presents the results of a 50-year research of the genepool of the winter wheat from the world's largest wheat collection of N.I. Vavilov Institute of Plant Industry (VIR) to investigate its resistance to the abiotic stress factors of the Moscow region and see how closely it matches the attributes of a wheat ideotype as postulated by N.I. Vavilov in 1935. The critical years in studying the wheat's winter resistance were 10 years out of 50: excessive water saturation during the year 2013; soil drought in 1988; and atmospheric drought in 1972 and 2010. During the investigation, the following gene pool features were analyzed: frost characterized by the cultivar Sojuz 50 (Russia), rapid temperature change, thawing, ice, and rotting resistance characterized by the cultivars Zarya 2 (Russia), Sv 75268, (Sweden), Caristerm and Tukan (Germany), PP 114-74 and Liwilla (Poland), Maris Ploughman and Granta (Great Britain), Titan (USA), Zdar (Czech), and Zenta (Switzerland); regeneration capacity in spring after poor wintering expressed by the cultivars Pamyati Fedina (Russia), TAW 3668.71 (Germany) and Rmo (Poland); resistance to excessive soil and air saturation exhibited by the cultivars Moskovskaya 39 (Russia), Tukan, Compal, Obelisk, Orestis, and Bussard (Germany); solid standing culm that is resistant to lodging characterized by the cultivars Tukan, Kronjuwel, Compal (Germany), Zenta (Switzerland), Moskovskaya 56 (Russia), and Hvede Sarah (Denmark); resistance to enzyme-mycotic depletion of seeds characterized by the cultivars Tukan, Compal, Obelisk, Orestis, Bussard (Germany), Sv 75268, Helge, VG 73394, Salut, Sv 75355 (Sweden), Zenta (Switzerland), Moskovskaya 39, and Ferrugineum 737.76 (Russia); and resistance to soil and atmospheric drought demonstrated by the cultivars Liessau, Heine Stamm, Severin, Neuzucht 14/4, Haynes, Rus 991, Halle 1020 (Germany), Gama (Poland), Sv 71536 (Sweden), and Moskovskaya 39 (Russia). Moreover, the cultivar Mironovskaya 808 (Ukraine) showed resistance to almost all abiotic stress factors studied. The performed study contributes towards the provision of potential sources of resistance to abiotic stress factors prevalent in the Moscow region that can be incorporated in advanced breeding programs.

Gene Pool of Winter Wheat from the World Collection of N.I. Vavilov Institute of Plant Industry (VIR) for Biotic Stress Resistance.

This paper presents the results of the 50 year-long research into the winter wheat gene pool from the VIR world collection in the Moscow region to assess biotic stress resistance following N.I. Vavilov's concept of the 'ideal variety', proposed in 1935. The Federal Scientific Selection and Technology Center for Horticulture and Nursery was responsible for the field studies of winter wheat, and the All-Russian Research Institute of Phytopathology and Russian State Agrarian University-Moscow Timiryazev Agricultural Academy-for phytopathological studies. The wheat collection was studied in compliance with the VIR Methodological Guidelines using the International COMECON list of descriptors for the genus Triticum L. Resistance against the enzyme-mycotic depletion of seeds (EMDS) was tested using original techniques. It was found that annual brown rust and powdery mildew attacks in the collection's winter wheat samples caused no significant economic damage. One case of Septoria head and leaf blotch, two cases of Fusarium head blight, one case of root rot, one case of barley yellow dwarf virus, 20 cases of EMDS, and three cases of 3rd-degree EMDS, i.e., seed germination in an ear, were recorded. The parent material resistant to the biotic stresses of the region was selected for breeding. Domestic breeders have created outstanding wheat varieties close to the 'ideal' as noted by N.I. Vavilov.

Genetic polymorphism of vir genes of Plasmodium vivax in Myanmar.

The Plasmodium vivax variant proteins encoded by vir genes are highly polymorphic antigens and are considered as one of key proteins of P. vivax for host immune evasion via antigenic variations. Because genetic diversity of these antigens is a critical hurdle in the development of an effective vaccine, understanding the genetic nature of the vir genes in natural population is important. In this study, we selected four vir genes (vir 4, vir 12, vir 21, and vir 27) previously used for genetic analysis in several studies and evaluated the genetic polymorphisms and phylogenetic relationship of these 4 vir genes in Myanmar P. vivax population. Taken all genetic diversity values, the vir 12 (S = 168, H = 17, Hd = 0.854, Tajima's D value = 2.91524) was the most genetically diverse gene and the vir 4 (S = 9, H = 4, Hd = 0.744, Tajima's D value = -0.49151) was the most conserved gene. All phylogenetic trees showed two clades, and vir 4 and 12 haplotypes from Myanmar were clustered in a distinct clade with those from India and Republic of Korea. These results confirmed the pattern of high genetic polymorphism of vir genes and provided information on vir gene for further functional research and studies focused toward the practical use of vir genes.

Orf Virus VIR Antagonizes p53-Mediated Antiviral Effects to Facilitate Viral Replication.

As a zoonotic disease, ovine contagious pustular dermatitis (Orf) is a serious threat to sheep as well as humans. Orf virus (ORFV) interferon resistance protein (VIR) is the principal virulence protein that encodes a dsRNA-binding protein to inhibit host antiviral response. p53 is one of the key proteins of the host antiviral innate immunity. It not only enhances type I interferon secretion but also induces apoptosis in infected cells, and plays a crucial role in the immune response against various viral infections. However, it remains to be elucidated what role p53 plays in ORFV replication and whether ORFV's own protein VIR regulates p53 expression to promote self-replication. In this study, we showed that p53 has an antiviral effect on ORFV and can inhibit ORFV replication. In addition, ORFV nonstructural protein VIR interacts with p53 and degrades p53, which inhibits p53-mediated positive regulation of downstream antiviral genes. This study provides new insight into the immune evasion mediated by ORFV and identifies VIR as an antagonistic factor for ORFV to evade the antiviral response.

Detection and phylogenetic analysis of Orf virus in Kashmir Himalayas.

Orf virus (ORFV) is a zoonotic pathogen that primarily infects sheep and goats, and is responsible for significant economic losses. ORFV is endemic in all the major sheep and goat rearing areas of the world including Indian subcontinent. However, the nature of ORFV circulating among sheep and goat in Kashmir Himalayas has not yet been characterized. In the present study, we describe natural outbreaks of ORFV in sheep and goats of Kashmir Himalayas. We detected the presence of ORFV in the scab lesion by PCR amplification of the major envelope protein (B2L) gene. We sequenced the virus interferon resistance (VIR) gene and determined their phylogenetic relationship with that of the published reference sequences. Phylogenetic analysis based on VIR gene revealed that the ORFV isolates from Kashmir Himalayas separated into main two clusters. The sheep isolates showed genetic homology with the sheep strains reported from Greece and Italy, whereas the goat-specific strain show homology with the goat strains reported from China. This study demonstrates the presence of ORFV infection in sheep and goats, and report first phylogenetic analysis of the ORFV strains prevalent in the Kashmir Himalayas.

Diversity of vir Genes in Plasmodium vivax from Endemic Regions in the Republic of Korea: an Initial Evaluation.

Variant surface antigens (VSAs) encoded by pir families are considered to be the key proteins used by many Plasmodium spp. to escape the host immune system by antigenic variation. This attribute of VSAs is a critical issue in the development of a novel vaccine. In this regard, a population genetic study of vir genes from Plasmodium vivax was performed in the Republic of Korea (ROK). Eighty-five venous blood samples and 4 of the vir genes, namely vir 27, vir 21, vir 12, and vir 4, were selected for study. The number of segregating sites (S), number of haplotypes (H), haplotype diversity (Hd), DNA diversity (π and Θw), and Tajima's D test value were conducted. Phylogenetic trees of each gene were constructed. The vir 21 (S=143, H=22, Hd=0.827) was the most genetically diverse gene, and the vir 4 (S=6, H=4, Hd=0.556) was the opposite one. Tajima's D values for vir 27 (1.08530, P>0.1), vir 12 (2.89007, P<0.01), and vir 21 (0.40782, P>0.1) were positive, and that of vir 4 (-1.32162, P>0.1) was negative. All phylogenetic trees showed 2 clades with no particular branching according to the geographical differences and cluster. This study is the first survey on the vir genes in ROK, providing information on the genetic level. The sample sequences from vir 4 showed a clear difference to the Sal-1 reference gene sequence, whereas they were very similar to those from Indian isolates.

Genetic polymorphisms in VIR genes among Indian Plasmodium vivax populations.

The vir genes are antigenic genes and are considered to be possible vaccine targets. Since India is highly endemic to Plasmodium vivax, we sequenced 5 different vir genes and investigated DNA sequence variations in 93 single-clonal P. vivax isolates. High variability was observed in all the 5 vir genes; the vir 1/9 gene was highly diverged across Indian populations. The patterns of genetic diversity do not follow geographical locations, as geographically distant populations were found to be genetically similar. The results in general present complex genetic diversity patterns in India, requiring further in-depth population genetic and functional studies.