Decoding the evolution and transmissions of the novel pneumonia coronavirus(SARS-CoV-2/HCoV-19)using whole genomic data

The outbreak of COVID-19 started in mid-December2019 in Wuhan, China. Up to 29 February 2020,SARS-CoV-2(HCoV-19/2019-nCoV) had infected more than 85 000 people in the world. In this study,we used 93 complete genomes of SARS-CoV-2 from the GISAID EpiFlu TM database to investigate the evolution and human-to-human transmissions of SARS-CoV-2 in the first two months of the outbreak.We constructed haplotypes of the SARS-CoV-2 genomes, performed phylogenomic analyses and estimated the potential population size changes of the virus. The date of population expansion was calculated based on the expansion parameter tau(τ)using the formula t=τ/2 u. A total of 120 substitution sites with 119 codons, including 79 non-synonymous and 40 synonymous substitutions, were found in eight coding-regions in the SARS-CoV-2 genomes.Forty non-synonymous substitutions are potentially associated with virus adaptation. No combinations were detected. The 58 haplotypes(31 found in samples from China and 31 from outside China)were identified in 93 viral genomes under study and could be classified into five groups. By applying the reported bat coronavirus genome(bat-RaTG13-CoV)as the outgroup, we found that haplotypes H13 and H38 might be considered as ancestral haplotypes,and later H1 was derived from the intermediate haplotype H3. The population size of the SARS-CoV-2 was estimated to have undergone a recent expansion on 06 January 2020, and an early expansion on 08 December 2019. Furthermore,phyloepidemiologic approaches have recovered specific directions of human-to-human transmissions and the potential sources for international infected cases.

Diversity Analysis of Chlorophyll, Flavonoid, Anthocyanin, and Nitrogen Balance Index of Tea Based on Dualex

The chemical compositions of tea(Camellia sinensis)are affected by numerous factors,such as cultivar,climate,leaf position,and cultivation pattern.However,under the same conditions,the chemical compositions are mainly determined by varieties.Therefore,we investigated the genetic diversity of chemical compositions of tea tree resources in China to screen excellent germplasm resources.Three chemical compositions index(including chlorophyll index,flavonoid index,and anthocyanin index)and the nitrogen balance index of tea leaves were measured in 102 tea germplasms planted in Chinese Tea Plants Improved Variety Germplasm Resources Nursery(CTPIVGRN)by Dualex on April 152019.Results showed that the chlorophyll,flavonoid,and anthocyanin contents and the nitrogen balance index significantly differed between the 102 tea germplasms.The genetic diversity index values were 2.005,2.246,1.599,and 1.838,and the average genetic diversity was 1.922.The 102 tea germplasms can be divided into four categories by cluster analysis under the genetic distance threshold of 11.These results suggest that the genetic diversity of tea germplasm resources in China is rich.This study’s results can serve as a basis for the diversified development and utilization of tea plant.

Chromosome-scale assembly of the Kandelia obovata genome

The mangrove Kandelia obovata(Rhizophoraceae)is an important coastal shelterbelt and landscape tree distributed in tropical and subtropical areas across East Asia and Southeast Asia.Herein,a chromosome-level reference genome of K.obovata based on PacBio,Illumina,and Hi-C data is reported.The high-quality assembled genome size is 177.99 Mb,with a contig N50 value of 5.74 Mb.A large number of contracted gene families and a small number of expanded gene families,as well as a small number of repeated sequences,may account for the small K.obovata genome.We found that K.obovata experienced two whole-genome polyploidization events:one whole-genome duplication shared with other Rhizophoreae and one shared with most eudicots(γevent).We confidently annotated 19,138 protein-coding genes in K.obovata and identified the MADS-box gene class and the RPW8 gene class,which might be related to flowering and resistance to powdery mildew in K.obovata and Rhizophora apiculata,respectively.The reference K.obovata genome described here will be very useful for further molecular elucidation of various traits,the breeding of this coastal shelterbelt species,and evolutionary studies with related taxa.

Effects of Nutrients on Growth and Yield of Shatian Pomelo Trees with Huanglongbing

[Objectives]In order to effectively alleviate Huanglongbing of Shatian pomelo trees,a nutrient preparation was developed and its effect on the growth and yield of Shatian pomelo was explored.[Methods]A field experiment was carried out with four treatments:control group,nutrient solution group,agent group,and nutrient solution+agent group,and the liquids were infused into the fruit trees through the trunk using a hanging bag.[Results]Through field trials,it was found that the nutrient solution treatment of fruit trees significantly increased the leaf chlorophyll content and nitrogen content,which increased by 17%and 12%compared with the control group,respectively,reaching(70.80±1.57)and(5.53±0.1)mg/kg,respectively;and the combined application of the nutrient solution and powder agents greatly alleviated the symptoms of Huanglongbing in Shatian pomelo plants,and significantly improved the bacterial disease index,photosynthetic intensity and yield,which increased by 152%,158%and 213.53%respectively,reaching(371.00±7.22),(406.67±7.09)and 23.15 kg/hm^2.[Conclusions]The use of the nutrient solution and agents greatly alleviated the symptoms of Huanglongbing of Shatian pomelo plants,and significantly improved the chlorophyll content,nitrogen content,bacterial disease index and photosynthetic intensity.Meanwhile,the number of fruit per plant and the weight of single fruit were better than other treatment groups and the control group,the technical operation was simple and the effect was obvious.This provides a certain reference basis for the prevention and control measures of Huanglongbing in Shatian pomelo plants.

Effects of Comprehensive Control Technology on Heavy Metal Content and Rice Yield in Northern Guangdong Province

In order to explore the application effect of the comprehensive control technology of"soil conditioning-organic planting-foliar control"in the rice area of northern Guangdong,the effects of combined application of different dosages of soil conditioner,bio-organic fertilizer and foliar control agent on heavy metal contents and yields of early and late rice were investigated based on field experiments.The results showed that different treatments of early rice and late rice all increased the yield.The yield increase rates of treatments 2,3 and 4 reached 4.9%,7.2%and 8.7%in early rice,respectively,and those in late rice reached 7.7%,7.8%and 9.7%,respectively.And the cadmium contents of early rice and late rice in treatments 2,3 and 4 were significantly reduced below the safe value.Taking into account factors such as cost,yield increase rate,and heavy metal compliance rate,the recommended application rate for early and late rice is conventional fertilization+soil conditioner 6000 kg/hm^(2)+bio-organic fertilizer 1800 kg/hm^(2)+foliar control agent 6000 ml/hm^(2).

Functional analysis of a novel C-glycosyltransferase in the orchid Dendrobium catenatum

Flavonoids,which are a diverse class of phytonutrients,are used by organisms to respond to nearly all abiotic stresses and are beneficial for human health.Glycosyltransferase,used during the last step of flavonoid biosynthesis,is important in flavonoid enrichment.However,little is known about glycosyltransferase in the orchid Dendrobium catenatum(D.officinale).In this study,we isolated a novel C-glycosyltransferase(designated DcaCGT)from the orchid D.catenatum by identifying and analyzing 82 putative genes in the GT1 family.DcaCGT could specifically catalyze not only di-C-glycosylation but also O-glycosylation.Apart from the normal function of catalyzing 2-hydroxynaringenin and phloretin to the respective di-C-glycosides,DcaCGT also catalyzes apigenin to cosmosiin.Targeted metabolic profiling of the substrates(2-hydroxynaringenin,phloretin,and apigenin)and products(vitexin,isovitexin,vicenin-2,nothofagin,3’,5’-di-C-glucosylphloretin,and cosmosiin)in different tissues showed that vicenin-2 was the most abundant product of this novel enzyme.Cosmosiin was detected in flowers and flower buds.We also established that DcaCGT functions expanded throughout the evolution of D.catenatum.Residual OGT activity may help D.catenatum resist drought stress.Our study illustrates the function,origin,and differentiation of DcaCGT and provides insights into glycosylation and molecular propagation processes,which can be used to improve the production of flavonoids by the cultivated medicinal plant D.catenatum.

Removal of the main inflorescence to induce reflowering of loquat

Loquat(Eriobotrya japonica Lindl.)is an evergreen fruit tree species of the Rosaceae,and its unique flowering time greatly hinders its production.To explore the artificial regulation of loquat flowering time,we removed the main inflorescence(by cutting it)to induce reflowering.For different loquat tree cultivars with different stages,the inflorescence was removed by cutting the main floral axis at two alternative positions:the upper or the lower position beneath the inflorescence,and it was found that the proportion of reflowering resulting from removing the upper position of the main floral axis of yellow-flesh loquat cultivars during the full-bloom stage was the highest.In addition,compared with those of the normal-growing panicles,the number of flower buds and branch axes of the reflowering panicles decreased significantly after cutting.Importantly,these newly produced inflorescences flowered 2–4 months later than normal-growing inflorescences did,effectively prolonging both the flowering and fruiting time.In addition,qRT-PCR results showed that EjFT1,EjFT2,EjAP1–1 and EjAP1–2 were highly expressed in the floral axis.These findings highlighted a new method for extending the production cycle of loquat and provided a reference for the flowering regulation of loquat and other economically important fruit tree species.

The Cymbidium genome reveals the evolution of unique morphological traits

The marvelously diverse Orchidaceae constitutes the largest family of angiosperms.The genus Cymbidium in Orchidaceae is well known for its unique vegetation,floral morphology,and flower scent traits.Here,a chromosomescale assembly of the genome of Cymbidium ensifolium(Jianlan)is presented.Comparative genomic analysis showed that C.ensifolium has experienced two whole-genome duplication(WGD)events,the most recent of which was shared by all orchids,while the older event was the t event shared by most monocots.The results of MADS-box genes analysis provided support for establishing a unique gene model of orchid flower development regulation,and flower shape mutations in C.ensifolium were shown to be associated with the abnormal expression of MADS-box genes.The most abundant floral scent components identi fied included methyl jasmonate,acacia alcohol and linalool,and the genes involved in the floral scent component network of C.ensifolium were determined.Furthermore,the decreased expression of photosynthesis-antennae and photosynthesis metabolic pathway genes in leaves was shown to result in colorful striped leaves,while the increased expression of MADS-box genes in leaves led to perianth-like leaves.Our results provide fundamental insights into orchid evolution and diversi fication.

Development of a Fubaiju Compound Tea Beverage

[Objectives]This study was conducted to develop a compound tea beverage with local characteristics.[Methods]A chrysanthemum compound tea beverage was developed using Fubaiju and Yunwu tea as the main raw materials,supplemented by wolfberry,through single factor test and orthogonal test,combined with sensory evaluation.[Results]The final product formula was the volume ratio of Fubaiju extract and Yunwu tea extract 2∶1,wolfberry juice 15%,white sugar 4%,citric acid 0.04%,and xanthan gum 0.05%.The prepared compound chrysanthemum tea beverage had the aroma and taste of Fubaiju,Yunwu tea and wolfberry,and tasted good.[Conclusions]This study provides reference for the deep processing and application of the two local special resources,Fubaiju and Yunwu tea.

Study on the Passivation Effect of Ca-Si Soil Conditioner on Heavy Metal Absorption by Rice

[Objectives] In order to solve the problem of heavy metal pollution in paddy fields,field experiments were carried out to study the effect of Ca-Si soil conditioner on heavy metal remediation in paddy fields. [Methods] A conventional planting mode( CK) was used as the control,and a Ca-Si soil conditioner( Ca-Si) treatment was set to analyze the differences in soil pH and heavy metal contents in different treatments. [Results]The content of cadmium in the paddy field exceeded the soil pollution risk control value of agricultural land by 59. 33%. The Ca-Si soil conditioner increased the pH value of paddy field soil by 0. 58 unit. The fixation rates of Ca-Si soil conditioner on chromium,arsenic,cadmium and plumbum reached 75. 96%,14. 09%,18. 93% and 7. 81% compared with the CK,respectively,and the available cadmium and lead contents were reduced by 82. 35% and 80. 00%,respectively. [Conclusions]This study provides ideas and references for the remediation of heavy metal pollution in paddy soil.

Study on Formula Optimization of Huangjing Zhima Pills

[Objectives]With Polygonati Rhizoma steamed and sundried for 9 times as the main raw material, a type of Huangjing Zhima Pills was developed and its optimal formula was studied. [Methods] The Huangjing Zhima Pills was developed with nine-steamed nine-sundried Polygonati Rhizoma as the main raw material by adding black sesame, black beans, and honey. Taking sensory score and texture properties as evaluation indexes, the optimal formula parameters of Huangjing Zhima Pills were determined by single factor experiments and an orthogonal test combined with a formula scoring method. [Results] The best formula of Huangjing Zhima Pills was addition amount of nine-steamed nine-sundried Polygonati Rhizoma 25%, addition amount of black bean powder 15%, addition amount of honey added 17%, and addition amount of black sesame powder 30%. The moisture content in the finished product was(13.367±0.056) g/100 g, and the total colony count, Escherichia coli, mold and yeast and other microbial indexes all met the standards. The Huangjing Zhima Pills prepared under these conditions had pleasant sesame flavor and Polygonati Rhizoma flavor, delicate and sweet tasted, and a slight aftertaste of sweetness. Meanwhile, Polygonatum, black sesame and black beans are all medicinal and food homologous plants with certain health care effects, and the Huangjing Zhima Pills prepared from them are healthy snacks that people can carry and eat easily. [Conclusions] This study further enhances the added value of Polygonatum and provides a new way for the high-value utilization of Polygonatum.

Ligand dose-dependent activation of signaling pathways through the gustatory receptor NlGr11 linked to feeding efficacy in Nilaparvata lugens

Insects often face both conditions with sufficient nutrients and conditions of undernutrition in the field.Through gustatory receptors,insects sense nutrients and regulate their physiological functions such as feeding and reproduction.However,it remains unclear whether signaling pathways activated by gustatory receptors depend on the concentration of nutrients and whether the difference in signaling pathways directly affects insects’physiological functions.Herein,we found that a sugar gustatory receptor,NlGr11,from the brown planthopper(BPH),Nilaparvata lugens,activated G protein-coupled signaling and ionotropic pathways when bound to high galactose concentration.BPHs subsequently demonstrated longer feeding times,feeding loads,and higher vitellogenin(NlVg)expression than BPHs exposed to high galactose concentrations,which only activated the ionotropic pathway.For the first time,our findings link plant nutrient conditions,signaling pathways activated by nutrients,and their gustatory receptors,and nutrient dose-dependent feeding efficacy and vitellogenin(Vg)expression in an insect.This will help us to better understand the molecular mechanism for insect feeding strategies on plants at different stages of nutritional conditions.

Lycium barbarum polysaccharides ameliorate canine acute liver injury by reducing oxidative stress,protecting mitochondrial function,and regulating metabolic pathways

The development of acute liver injury can result in liver cirrhosis,liver failure,and even liver cancer,yet there is currently no effective therapy for it.The purpose of this study was to investigate the protective effect and therapeutic mechanism of Lycium barbarum polysaccharides(LBPs)on acute liver injury induced by carbon tetrachloride(CCl_(4)).To create a model of acute liver injury,experimental canines received an intraperitoneal injection of 1 mL/kg of CCl_(4)solution.The experimental canines in the therapy group were then fed LBPs(20 mg/kg).CCl_(4)-induced liver structural damage,excessive fibrosis,and reduced mitochondrial density were all improved by LBPs,according to microstructure data.By suppressing Kelch-like epichlorohydrin(ECH)-associated protein 1(Keap1),promoting the production of sequestosome 1(SQSTM1)/p62,nuclear factor erythroid 2-related factor 2(Nrf2),and phaseⅡdetoxification genes and proteins downstream of Nrf2,and restoring the activity of anti-oxidant enzymes like catalase(CAT),LBPs can restore and increase the antioxidant capacity of liver.To lessen mitochondrial damage,LBPs can also enhance mitochondrial respiration,raise tissue adenosine triphosphate(ATP)levels,and reactivate the respiratory chain complexes I–V.According to serum metabolomics,the therapeutic impact of LBPs on acute liver damage is accomplished mostly by controlling the pathways to lipid metabolism.9-Hydroxyoctadecadienoic acid(9-HODE),lysophosphatidylcholine(Lyso PC/LPC),and phosphatidylethanolamine(PE)may be potential indicators of acute liver injury.This study confirmed that LBPs,an effective hepatoprotective drug,may cure acute liver injury by lowering oxidative stress,repairing mitochondrial damage,and regulating metabolic pathways.

Anti-wear properties on 20CrMnTi steel surfaces with biomimetic non-smooth units

In order to gain a sufficient wear resistance for applications, the biomimetic non-smooth units in concave were fabricated on the surfaces of 20CrMnTi steel using a biomimetic laser remelting technology. The diameter and distribution of the concaves were optimized using orthogonal experiment. The microstructures of the biomimetic non-smooth units were examined. The anti-wear behaviors were investigated by the rolling wear test with lubricant. The results of wear tests indicated that the biomimetic surfaces exhibit a higher anti-wear ability than the smooth surfaces. The biomimetic surface with concaves of 250 μm in diameter and transverse distance of 270 μm and longitudinal distance of 400 μm exhibits the best anti-wear property. The enhancement of wear resistance can be mainly attributed to the action of biomimetic non-smooth units and the super fined microstructure and hardness in the biomimetic unit zones.