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Potato virus Y (PVY) is an important viral pathogen of the plant family Solanaceae. However, it has not been reported that PVY infects zucchini (Cucurbita pepo L). Zucchini plants showing symptoms of leaf mosaic and fruit ringspot were collected from Inner Mongolia, China. Using RT-PCR, we amplified the PVY-specific bands in zucchini (PVY-Zu isolate). Further, we found that the viral pathogen could infect Nicotiana benthamiana via mechanical inoculation with the extract of the zucchini leaves. Filamentous virions were observed in infected N. benthamiana plants under a transmission electron microscope. Additionally, the complete genomic fragment of the PVY-Zu isolate was obtained via RT-PCR and RACE analysis, containing 9662 nucleotides (nt) excluding the 3′-terminal poly (A) tail. The 5′ and 3′ untranslated regions (UTRs) were 150 nt and 329 nt, respectively, while the putative polyprotein contained 3061 amino acids. Comparison of the PVY-Zu isolate with 19 other PVY isolates revealed that they shared nucleotide sequence identities of ~ 83.1–99.8% at the complete genomic level. Based on the complete genome sequences, phylogenetic analysis showed that PVY-Zu clustered with PVY strain N605 (X97895-PVY), a Swiss necrotic isolate of PVY. Compared with the complete genome sequence of X97895-PVY, the PVY-Zu isolate had a deletion of a 39-nt fragment in its 5′ UTR and 22 mutated nucleotides without changes in the amino acids. Moreover, although the similarity in the identities of the PVY-Zu isolate and PVY N isolate N-Jg (AY166867) was about 96.2%, the former had a deletion of a 38-nt fragment in its 5′ UTR and 334 mutations among the viral genome, which resulted in 61 amino acid changes. However, we could not detect any recombination throughout the PVY-Zu genome. To our knowledge, this is the first study reporting that PVY could infect zucchini plants, thus broadening the host diversity of the viral pathogen. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13337-020-00647-2.

Prunus necrotic ringspot virus (PNRSV) is an important virus of stone fruit trees (Prunus sp.). In this study, complete genomic sequences of five PNRSV isolates from P. persica (Pea1 and Pea4), P. avium (Che1 and Che2) and P. cerasifera (P.cerasifera1) in Inner Mongolia of China were determined and analyzed together with other previously published PNRSV sequences in the world. Phylogenetic analysis based on RNA3 sequences divided the five isolates into PV32 (Che1, Che2 and P.cerasifera1) and PV96 (Pea1 and Pea4) group, and re-grouped PNRSV isolates in the world into six groups including a new proposed group (PchMx-Azt) composed of two flowering peach isolates from Mexico. Distinct origins for RNAs of isolate P.cerasifera1 suggested potential reassortment in evolution of PNRSV. In addition, nine recombination events were predicted in RNA1–3 among the isolates.

The rumen is the hallmark organ of ruminants and hosts a diverse ecosystem of microorganisms that facilitates efficient digestion of plant fibers. We used 897 transcriptomes from three Cetartiodactyla lineages: ruminants, camels and cetaceans, as well as data from ruminant comparative genomics and functional assays to explore the genetic basis of rumen origin and evolution. Comparative analyses reveal that the rumen and the first-chamber stomachs of camels and cetaceans shared a common tissue origin from the esophagus. The rumen recruited genes from other tissues/organs and up-regulated many esophagus genes to aquire functional innovations involving epithelium absorption, improvement of the ketone body metabolism and regulation of microbial community. These innovations involve such genetic changes as ruminant-specific conserved elements, newly evolved genes and positively selected genes. Our in vitro experiements validate the functions of one enhancer, one positively selected gene and two newly evolved antibacterial genes. Our study provides novel insights into the origin and evolution of a complex organ.

The objective of this study was to determine the dry matter (DM) and crude protein (CP) degradation parameters of several commercially available concentrate feed ingredients used in Shaanbei White Cashmere Goat (SWCG). Three 4-year-old female SWCGs fitted with permanent rumen fistula were fed with corn straw and concentrate feed. Tested energy and protein feed ingredients were corn, wheat bran (WB), corn germ meal, soybean meal (SBM), rape seed meal (RSM), and distillers dried grains. The feed samples were placed in a nylon bag and incubated in the rumen for 0, 2, 6, 12, 24, 36, and 48 h to measure the ruminal disappearance of DM and CP. The exponential model was used to calculate the degradation kinetics. There were significant differences between sources in terms of DM and CP disappearance and degradability. In terms of energy feed ingredients, the potential degradability of DM and CP of corn was significantly higher than those of the other energy feed ingredients, whereas the effective degradability (ED) of CP of WB at three outflow rates was significantly higher than those of the others. In protein feed ingredients, SBM had the highest potential degradability of DM and CP. Furthermore, the ED of DM of SBM at three outflow rates was significantly higher than those of the other protein feed ingredients, whereas the ED of CP of RSM at three outflow rates was significantly higher than those of others. Those feed ingredients with low degradability can increase the bypass nutrients, which will be digested in the small intestine. The degradation parameters obtained in this experiment using SWCG would be useful in improving the accuracy of formulation of cashmere goat diet in Northwest of China.

Tobacco black shank (TBS) caused by Phytophthora nicotianae is destructive to almost all kinds of tobacco cultivars and is widespread in many tobacco-planted countries. Here, an isolated plant growth-promoting rhizobacteria (PGPR) strain Ba168 is promise in biocontrol of TBS. In vitro assays disclosed a strong P. nicotianae suppression activity and the field utilization potential (FUP) by characterized the crude extract of culture filtrates of Ba168. P. nicotianae’s growth was inhibited by the crude extract at minimum inhibitory concentration (MIC) of 5μl/mL. Extracellular conductivity, pH and the wet, dry weight of P. nicotianae’s mycelia, were significantly different after treated with different concentrations of the crude extract and the deformity and perforation of treated P. nicotianae’s hyphae can be observed in scanning electron microscope (SEM) analysis. Proteome characterizations of the crude extract were used as supplementary proofs that further evaluated FUP of Ba168. We then identified strain Ba168 as B. amyloliquefaciens by its genetic and phenotypic characteristics. Field assays comparatively evaluated TBS control efficacy of these PGPRs and agrochemicals. Pooling analysis of the results showed that the biocontrol efficacy of Ba168 preparation is only lower than Mixture of Propamocarb hydrochloride and Azoxystrobin (MPA) but better than other tested subjects. Although the existence of differences in biocontrol efficacy, PGPR preparations effectively reduced the disease index of tobacco.ImportanceThis work demonstrates the promising biocontrol potential of B. amyloliquefaciens Ba168 and highlights the positive roles of PGPR in suppression of this soil-borne disease.

In this study, two phenol compounds, magnolol and honokiol, were extracted from Magnolia officinalis and identified by LC-MS, 1H- and 13C-NMR. The magnolol and honokiol were shown to be effective against seven pathogenic fungi, including Alternaria alternata (Fr.) Keissl, Penicillium expansum (Link) Thom, Alternaria dauci f.sp. solani, Fusarium moniliforme J. Sheld, Fusarium oxysporum Schltdl., Valsa mali Miyabe &amp, G. Yamada, and Rhizoctonia solani J.G. K&uuml, hn, with growth inhibition of more than 57%. We also investigated the mechanisms underlying the potential antifungal activity of magnolol and honokiol. The results showed that they inhibited the growth of A. alternata in a dose-dependent manner. Moreover, magnolol and honokiol treatment resulted in distorted mycelia and increased the cell membrane permeability of A. alternata, as determined by conductivity measurements. These results suggest that magnolol and honokiol are potential antifungal agents for application against plant fungal diseases.

Tobacco black shank (TBS) caused by Phytophthora nicotianae is destructive to almost all tobacco cultivars and is widespread in many tobacco-growing countries. Through lab study and field test, we isolated plant growth-promoting rhizobacteria (PGPR) strain Ba168 which is a promising biocontrol strain of TBS. Ba168 was isolated from 168 soil samples and identified as Bacillus velezensis by its genetic and phenotypic characteristics. A susceptibility test indicated that the P. nicotianae antagonistic materials of Ba168 in extracellular metabolites were composed of effective and stable proteins/peptides. P. nicotianae's growth was suppressed by the ammonium sulfate precipitation of Ba168 culture filtrates (ASPBa) at a minimum inhibitory concentration of 5 μg/mL. Extracellular conductivity, pH, and the wet/dry weights of P. nicotianae's mycelia, along with scanning electron microscope analysis, suggested that Ba168-derived proteins/peptides could effectively inhibit P. nicotianae by causing irreversible damage to its cell walls and membranes. Protein identification of ASPBa supported these results and identified many key proteins responsible for various biocontrol-related pathways. Field assays of TBS control efficacy of many PGPRs and agrochemicals showed that all PGPR preparations reduced the disease index of tobacco, but Ba168 was the most effective. These results demonstrated the importance of Bacillus-derived proteins/peptides in the inhibition of P. nicotianae through irreversible damage to its cell wall and membrane; and the effectiveness of PGPR strain B. velezensis Ba168 for biocontrol of the soil-borne disease caused by P. nicotianae.

Tail fat content affects meat quality, and it varies in different sheep breeds. Theoretically, lipid metabolism contributes to variation in tail fat content. Tail length, tail width, and tail girth were measured in live Tong sheep (with both short fat tail and long fat tail), Shaanbei fine wool sheep (long thin tail), Tan sheep (short fat tail), Kazakh sheep (hip fat tail), and Tibetan sheep (short thin tail). The expression levels of genes related to tail adipose tissue lipid metabolism were investigated, which included lipogenetic genes (PPARγ and FAS) and lipolytic gene (HSL). Differences were observed (P0.05) in PPARγ mRNA expression levels in the different breeds; FAS mRNA expression levels did not differ (P0.05) in Tong sheep with short fat tail, Tong sheep with long fat tail, Shaanbei fine wool sheep, and Tibetan sheep; HSL mRNA expression levels were not different (P0.05) in Tong sheep. PPARγ and HSL protein expression levels differed (P0.05) between the different breeds; FAS protein expression levels were different (P0.05) in Tong sheep with long fat tails, Tan sheep, Kazakh sheep, and Tibetan sheep, but did not differ (P0.05) in Tong sheep with short fat tails and Shaanbei fine wool sheep. These results provide useful information to further understand the function of PPARγ, FAS, and HSL in sheep tail lipid metabolism, which should be applicable to studies on the regulation of fat deposition and improvement of meat quality.