Perfluorooctanoic acid(PFOA) and perfluorooctanesulfonic acid(PFOS) concentrations in the South Korean agricultural environment: A national survey

Research on the occurrence of perfluorochemicals （PFCs） such as perfluorooctanesulfonic acid （PFOS） and perfluorooctanoic acid （PFOA） in the agricultural environment is lacking, in spite of their potential risk via food chain transfer from aquatic and soil-plant systems to animals and/or humans. In the present study, for the first time, soil and water samples collected from 243 different agricultural sites adjacent to waste water treatment plants （WWTPs） belonging to 81 cities and 5 provinces with different levels of industrialization in South Korea were monitored for concentrations of PFOS and PFOA by use of solid phase extraction and liquid chromatography-tandem mass spectroscopy （LC-MS/MS）. Significant mean concentrations of PFOA （0.001-0.007 tJg L-1 water and 〈0.05-1.573 tJg kg-1 soil） and PFOS （0.001-0.22 tJg L-1 water and 〈0.05-0.741 pg kg-1 soil） were found in all samples. Concentrations of PFCs in soils were high, highlighting that soil is an important sink for PFCs in the agricultural environment. Samples from near WWTPs in Gyeongsang Province contained the highest concentrations of PFOS and PFOA, reflecting the concentration of heavy industry in the province. The concentrations of PFCs in agricultural water （most samples 〈0.05 pg L-~） and soils （most samples 〈1 IJg kg-~） from South Korea were less than acceptable guideline values, indicating that South Korea is not a hotspot of PFOS and PFOA contamination and that there is negligible risk to human and ecological health from these chemicals. However, further studies investigating the seasonal variation in PFOA, PFOS and other perfluorochemical concentrations in the agricultural environment are needed.

Gene editing of authentic Brassica rapa flavonol synthase 1 generates dihydroflavonol-accumulating Chinese cabbage

Flavonols are the major class of flavonoids of green Chinese cabbage(Brassica rapa subsp.pekinensis).The B.rapa genome harbors seven flavonol synthase genes(BrFLSs),but they have not been functionally characterized.Here,transcriptome analysis showed four BrFLSs mainly expressed in Chinese cabbage.Among them,only BrFLS1 showed major FLS activity and additional flavanone 3β-hydroxylase(F3H)activity,while BrFLS2 and BrFLS3.1 exhibited only marginal F3H activities.We generated BrFLS1-knockout(BrFLS1-KO)Chinese cabbages using CRISPR/Cas9-mediated genome editing and obtained transgene-free homozygous plants without off-target mutation in the T1 generation,which were further advanced to the T2 generation showing normal phenotype.UPLC-ESI-QTOF-MS analysis revealed that flavonol glycosides were dramatically decreased in the T2 plants,while dihydroflavonol glycosides accumulated concomitantly to levels corresponding to the reduced levels of flavonols.Quantitative PCR analysis revealed that the early steps of phenylpropanoid and flavonoid biosynthetic pathway were upregulated in the BrFLS1-KO plants.In accordance,total phenolic contents were slightly enhanced in the BrFLS1-KO plants,which suggests a negative role of flavonols in phenylpropanoid and flavonoid biosynthesis in Chinese cabbage.Phenotypic surveys revealed that the BrFLS1-KO Chinese cabbages showed normal head formation and reproductive phenotypes,but subtle morphological changes in their heads were observed.In addition,their seedlings were susceptible to osmotic stress compared to the controls,suggesting that flavonols play a positive role for osmotic stress tolerance in B.rapa seedling.In this study,we showed that CRISPR/Cas9-mediated BrFLS1-KO successfully generated a valuable breeding resource of Chinese cabbage with distinctive metabolic traits and that CRISPR/Cas9 can be efficiently applied in functional Chinese cabbage breeding.

OsWRKY65 enhances immunity against fungal and bacterial pathogens in rice

Diverse bacterial and fungal pathogens attack plants,causing biotic stress and severe yield losses globally.These losses are expected to become more serious as climate change improves conditions for many pathogens.Therefore,identifying genes conferring broad-spectrum disease resistance and elucidating their underlying mechanisms provides important resources for plant breeding.WRKY transcription factors affect plant growth and stress responses.However,the functions of many WRKY proteins remain to be elucidated.Here,we demonstrated the role of rice(Oryza sativa)WRKY groupⅢtranscription factor OsWRKY65 in immunity.OsWRKY65 localized to the nucleus and acted as transcriptional repressor.Genetic and molecular functional analyses showed that OsWRKY65 increases resistance to the fungal pathogen Fusarium fujikuroi through downregulation of GA signaling and upregulation of JA signaling.Moreover,OsWRKY65 modulated the expression of the key genes that confer susceptibility or resistance to Xanthomonas oryzae pv.oryzae to enhance immunity against the pathogen.In particular,OsWRKY65directly bound to the promoter region of OsSWEET13 and repressed its expression.Taken together,our findings demonstrate that the OsWRKY65 enhances resistance to fungal and bacterial pathogens in rice.

Genome-wide Analysis of MYB Gene Family in Potato Provides Insights into Tissue-specific Regulation of Anthocyanin Biosynthesis

The MYB transcription factor is one of the largest gene families in plants,playing an important role in regulating plant growth,development,response to stress,senescence,and especially the anthocyanin biosynthesis.In this study,A total of 217 MYB genes,including 901R-MYBs,124 R2R3-MYBs,and 3 R1R2R3-MYBs have been identified from the potato genome.The 1R-MYB and R2R3-MYB family members could be divided into 20 and 35 subgroups respectively.Analysis of gene structure and protein motifs revealed that members within the same subgroup presented similar exon/intron and motif organization,further supporting the results of phylogenetic analysis.Potato is an ideal plant to reveal the tissue-specific anthocyanins biosynthesis regulated by MYB,as the anthocyanins could be accumulated in different tissues,showing colorful phenotypes.Five pairs of colored and colorless tissues,stigma,petal,stem,leaf,and tuber flesh,were applied to the transcriptomic analysis.A total of 70 MYB genes were found to be differentially expressed between colored and colorless tissues,and these differentially expressed genes were suspected to regulate the biosynthesis of anthocyanin of different tissues.Co-expression analysis identified numerous potential interactive regulators of anthocyanins biosynthesis,involving 39 MYBs,24 bHLHs,2 WD-repeats,and 29 biosynthesis genes.Genome-wide association study(GWAS)of tuber flesh color revealed amajor signal at the end of Chromosome 10,which was co-localized with reported I gene(StMYB88),controlling tuber peel color.Analyses of DEGs(Differentially Expression Genes)revealed that both StMYB88 and StMYB89 were closely related to regulating anthocyanin biosynthesis of tuber flesh.This work offers a comprehensive overview of the MYB family in potato and will lay a foundation for the functional validation of these genes in the tissue-specific regulation of anthocyanin biosynthesis.

Identification of Rice Accessions Associated with K+/Na+ Ratio and Salt Tolerance Based on Physiological and Molecular Responses

The key for rice plant survival under Na Cl salt stress is maintaining a high K^+/Na^+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in breeding. Use of molecular markers in tandem with physiological studies will help in better identification of salt tolerant rice accessions. Eight rice accessions along with the check Dongjin were screened using 1/2 Yoshida solution with 50 mmol/L NaCl at the seedling stage. The accessions IT001158, IT246674, IT260533 and IT291341 were classified as salt tolerant based on their K^+/Na^+ ratios. Seventeen SSR markers reported to be associated with K^+/Na^+ ratio were used to screen the accessions. Five SSR markers(RM8053, RM345, RM318, RM253 and RM7075) could differentiate accessions classified based on their K^+/Na^+ ratios. Banding pattern of the accessions was scored compared to the banding pattern of Dongjin. The study differentiated accessions based on their association of K^+/Na^+ ratio with molecular markers which are very reliable. These markers can play a significant role in screening large set of rice germplasms for salt tolerance and also help in identification of high-yielding varieties with better salt tolerance. The salt tolerant accessions can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

Photosynthesis,Metabolite Composition and Anatomical Structure of Oryza sativa and Two Wild Relatives,O.grandiglumis and O.alta

Photosynthesis, enzyme activities and metabolite pools associated with primary carbon metabolism in leaves were studied in O. grandiglumis and O. alta （wild relatives of rice which produce high biomass） versus O. sativa （a japonica cultivar and a indica-japonica hybrid） to assess their potential for identifying traits which might be utilized to enhance rice productivity. The wild relatives had higher rates of photosynthesis on a fresh weight basis, and higher water use efficiency than the O. sativa lines. There were no striking differences in activities of a number of key enzymes in carbon and nitrogen metabolism between the wild relatives and cultivated rice lines. Along with higher rates of photosynthesis on a fresh weight basis, the leaves of the two wild species had higher nitrate content, higher levels of starch, glucose and fructose, and higher levels of organic acids （malate, succinate and acetate）, compared to the O. sativa lines. The results suggested that O. grandiglumis and O. alta have differences in physiology and primary metabolism which might be exploited to improve growth and productivity of cultivated rice.

Whole-genome,transcriptome,and methylome analyses provide insights into the evolution of platycoside biosynthesis in Platycodon grandiflorus,a medicinal plant

Triterpenoid saponins(TSs)are common plant defense phytochemicals with potential pharmaceutical properties.Platycodon grandiflorus(Campanulaceae)has been traditionally used to treat bronchitis and asthma in East Asia.The oleanane-type TSs,platycosides,are a major component of the P.grandiflorus root extract.Recent studies show that platycosides exhibit anti-inflammatory,antiobesity,anticancer,antiviral,and antiallergy properties.However,the evolutionary history of platycoside biosynthesis genes remains unknown.In this study,we sequenced the genome of P.grandiflorus and investigated the genes involved in platycoside biosynthesis.The draft genome of P.grandiflorus is 680.1 Mb long and contains 40,017 protein-coding genes.Genomic analysis revealed that the CYP716 family genes play a major role in platycoside oxidation.The CYP716 gene family of P.grandiflorus was much larger than that of other Asterid species.Orthologous gene annotation also revealed the expansion ofβ-amyrin synthases(bASs)in P.grandiflorus,which was confirmed by tissue-specific gene expression.In these expanded gene families,we identified key genes showing preferential expression in roots and association with platycoside biosynthesis.In addition,wholegenome bisulfite sequencing showed that CYP716 and bAS genes are hypomethylated in P.grandiflorus,suggesting that epigenetic modification of these two gene families affects platycoside biosynthesis.Thus whole-genome,transcriptome,and methylome data of P.grandiflorus provide novel insights into the regulation of platycoside biosynthesis by CYP716 and bAS gene families.

Towards smart farming solutions in the U.S.and South Korea:A comparison of the current status

Smart farming solutions combine information,data software tools,and technology with the intent to improve agricultural production.While smart farming concepts are well described in the literature,the potential societal impacts of smart farming are less conspicuous.To demonstrate how smart farming solutions could influence future agricultural production,agri-business and rural communities and their constituents,this article compares smart farming approaches and reasons behind the pursuit of smart farming solutions by the U.S.and South Korea.The article compares agricultural assets and productivity among the two countries as well as the technical and societal challenges impacting agricultural production as a basis to understanding the motivations behind and pathways for developing smart farming solutions.In doing so,the article compares some of the technological and social advantages and disadvantages of smart farming,dependending on the choice and implementation of smart farming solutions.The South Korean government has implemented a national policy to establish smart farming communities;a concept that addresses the entire agri-food supply chain.In the U.S.,a national plan to develop smart farming technologies does not exist.However,discrete smart farming solutions driven mainly by competition in the private sector have resulted in high-tech solutions that are advancing smart farming concepts.The differences in approaches and reporting of successes and failures between the two countries could facilitate the rate of evolution of successful smart farming solutions,and moreover,could provide pathways to facilitate sustainable development goals in developing countries where smart farming activities are currently underway.

Laboratory studies of rice bran as a carbon source to stimulate indigenous microorganisms in oil reservoirs

There is a great interest in developing cost-efficient nutrients to stimulate microorganisms in indigenous microbial enhanced oil recovery（IMEOR） processes.In the present study,the potential of rice bran as a carbon source for promoting IMEOR was investigated on a laboratory scale.The co-applications of rice bran,K2HPO4 and urea under optimized bio-stimulation conditions significantly increased the production of gases,acids and emulsifiers.The structure and diversity of microbial community greatly changed during the IMEOR process,in which Clostridium sp.,Acidobacteria sp.,Bacillus sp.,and Pseudomonas sp.were dominant.Pressurization,acidification and emulsification due to microbial activities and interactions markedly improved the IMEOR processes.This study indicated that rice bran is a potential carbon source for IMEOR.

Systemic Activation of Defensive Enzymes and Protection in Tobacco Plantlets against <i>Phytophthora nicotianae</i>Induced by Oligosaccharins

Oligosaccharins are potent biomolecules which activate defense responses and resistance in tobacco plants. However, it is not known the systemic behavior of defensive enzymes activated by these elicitors. In this work, the dynamic behavior of key defensive enzymes was evaluated in tobacco plant leaves previously treated through the roots with chitosan polymer (CH), chitosan (COS) and pectic (OGAS) oligosaccharides and Spermine (Sp). All macromolecules tested activated protein levels and defense enzymatic activity in tobacco leaves but with different response dynamics among them and depending on the biochemical variable evaluated. Defense response above control levels were detected since 12 hours after treatments and it consisted in a biphasic behavior with two peaks for PAL (EC 4.3.1.5) and β 1 - 3 glucanase (EC 3.2.1.6) enzymatic activities. The highest enzymatic levels for these enzymes were achieved at 48 hours in plantlets elicited with COS and at 72 hours for those plants treated with chitosan polymer, while the highest POD (EC 1.11.1.6) activity was detected with CH between 48 and 72 hours. These results demonstrated systemic defense activation by oligosaccharins in tobacco whose dynamic of defense response is affected by the kind of oligosaccharins tested. When applying OGAS by foliar spray on tobacco, systemic resistance against Phytoththora nicotianae was induced and plantlets were protected with the low concentration tested by 46% under the bioassays conditions performed. Moreover, enzymatic determinations on roots and leaves previous to plant-pathogen interaction showed increments above 30% of control levels for PAL and POD activities. It means that oligosaccharins activate local and systemic defense responses in plants in the absent of pathogen infection.

Profit Analysis by Soil Carbon Sequestration with Different Composts and Cooperated with Biochar during Corn (Zea mays) Cultivation Periods in Sandy Loam Soil

Despite the ability of biochar to enhance soil fertility and to sequester soil carbon, its potential reduction of green house gas emissions and profit analysis with different organic composts and cooperated with biochar for crop cultivation have been a few evaluated. This study was conducted to estimate their greenhouse gas emission reduction and profit analysis by soil carbon sequestration with different organic composts and cooperated with biochar application during corn cultivation periods. For the experiment, the treatments were consisted of aerobic digestate of swine wastes (AD), pig compost as the control (PC), cow compost (CC) and pig compost cooperated with 1% biochar (PC + 1% biochar). The soil texture used in this study was sandy loam, and application rates of chemical fertilizer were 190-39-221 kg·ha-1 (N-P2O5-K2O) as recommended amount after soil test. The soil samples were periodically taken at every 15 day intervals during the experimental periods. It was observed that soil carbon sequestration by AD, CC and PC + 1% biochar application was estimated to be 429 kg·ha-1, 2366 kg·ha-1, and 3978 kg·ha-1, and their CO2-e emission reductions were estimated to be 0.16 tones for AD, 0.87 tones for CC, and 14.58 tones for PC + 1% biochar per hectar for corn cultivation periods. Their profits were estimated at $14.58 for lowest and $451.90 for highest. In Korea Climate Exchange, it was estimated to be $115.20 per hectar of corn cultivation with PC + 1% biochar. So, the price of CO2 per hectar for corn cultivation with PC + 1% biochar was high at 16.8 times relative to cow compost treatment only. For the plant growth response, it was observed that plant height and fresh ear yield were not significantly different among the treatments. Therefore, these experimental results might be fundamental data for assuming a carbon trading mechanism exists for biochar soil application in agricultural practices.

韩国的土地利用规划体系和农村综合开发规划

韩国的土地国情和农业经营特点与我国十分相似。文章分析了韩国土地利用规划体系的构成及其主要特点,以及在农村综合开发和农村城市化过程中的作用。最后简要论述了乡村土地利用规划在中国国土规划中的重要性和迫切性,希望能为我国的农村综合开发和城镇化发展提供一些借鉴。

Salt Tolerance in Rice: Focus on Mechanisms and Approaches

Salt tolerance is an important constrain for rice, which is generally categorized as a typical glycophyte. Soil salinity is one of the major constraints affecting rice production worldwide, especially in the coastal areas. Susceptibility or tolerance of rice plants to high salinity is a coordinated action of multiple stress responsive genes, which also interacts with other components of stress signal transduction pathways. Salt tolerant varieties can be produced by marker-assisted selection or genetic engineering by introducing salt-tolerance genes. In this review, we have updated on mechanisms and genes which can help in transferring of the salt tolerance into high-yielding rice varieties. We have focused on the need for integrating phenotyping, genomics, metabolic profiling and phenomics into transgenic and breeding approaches to develop high-yielding as well as salt tolerant rice varieties.

利用桑木人工栽培药用真菌灵芝(Phellinus linteus)的研究(英文)

比较了利用无菌短木接种法、钻孔接种法和端木夹心接种法等接种方法接种桑树段木后Phellinus linteus的菌丝生长和定殖状况。研究表明利用灭菌的短木接种P.linteus,生长和定殖良好,传统的钻孔接种法和端木夹心接种法菌丝生长定殖不好。P.linteus在20 cm长的桑木上生长和定殖所需的最适的含水量为42%,接种后12 h,P.linteus立即进入快速生长期。接种后的桑木埋入土壤中需要5～6个月产生担子果,在培养室内温度为31～35℃,相对湿度大于96%时有利于子实体的形成。

提高平菇产量的栽培新技术(英文)

探讨了一系列有关菇床的制备、栽培料的处理和发酵等提高平菇产量的栽培措施。为了提高锯木屑的利用率,在制备菇床时引进了发酵技术;为了解决生长中一些基础问题,改进了培养基质的处理方法。同时也评估了聚乙烯薄膜钻孔覆盖技术对两种平菇(Pleurotus ostreatus和P.sajor-caju)产量和品质的影响。在平菇菇床制备的过程中,为避免其它真菌菌丝的污染,使用了发酵后的锯木屑法。结果表明,所用的3种添加物中,稻糠是促使培养基质升温效率最高的添加物,可以升高到70℃。应用发酵锯木屑添加稻糠生产的菌丝的活力和密度大大高于非发酵锯木屑培养,并且其上可见平菇原基的形成。发酵锯木屑在预防木霉的污染上显示了一定的潜能,而非发酵锯屑在接种后30 d内对木霉无能为力。研究了堆料(发酵)对平菇培养基物效率的提高能力。在白杨树锯木屑和冬蘑菇的栽培废料中加入10 %的米糠后,在20～28℃下室外堆放12 d。在发酵锯木屑钵中发酵的持续时间缩短3 d。平菇在发酵基质中生长可以加快子实体原基的形成。用棉籽壳和发酵的白杨锯木屑混合可以获得最高的产量(742 g),而对照只有663 g。另外,用白杨锯木屑与冬蘑菇培养废料混合可以最有效提高发酵效率。在棉籽壳中添加发酵的锯木屑和可循环的农副产品可以促进培养基质发酵和子实?

Brassinosteroids and Plant Responses to Heavy Metal Stress. An Overview

Soil contamination with heavy metals has become a world-wide problem, leading to the loss in agricultural productivity. Plants have a remarkable ability to take up and accumulate heavy metals from their external environment and it is well known that high levels of heavy metals affect different physiological and metabolic processes. Brassinosteroids are considered as the sixth class of plant hormones and they are essential for plant growth and development. These compounds are able of inducing abiotic stress tolerance in plants. In this paper, information about brassinosteroids and plant responses to heavy metal stress is reviewed.

Conservation and Diversification of the SHR-SCR- SCL23 Regulatory Network in the Development of the Functional Endodermis in Arabidopsis Shoots

Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT （SHR）, SCARECROW （SCR）, and SCARECROW-LIKE 23 （SCL23）. Recently, it has been shown that the SHR-SCR-SCL23 regulatory module is also essential for spec- ification of the endodermis （known as the bundle sheath） in leaves. Nevertheless, compared with what is known about the role of the SHR-SCR-SCL23 regulatory network in roots, the molecular interactions of SHR, SCR, and SCL23 are much less understood in shoots. Here, we show that SHR forms protein com- plexes with SCL23 to regulate transcription of SCL23 in shoots, similar to the regulation mode of SCR expression. Our results indicate that SHR acts as master regulator to directly activate the expression of SCR and SCL23. In the SHR-SCR-SCL23 network, we found a previously uncharacterized negative feed- back loop whereby SCL23 modulates SHR levels. Through molecular, genetic, physiological, and morpho- logical analyses, we also reveal that the SHR-SCR-SCL23 module plays a key role in the formation of the endodermis （known as the starch sheath） in hypocotyls. Taken together, our results provide new insights into the regulatory role of the SHR-SCR-SCL23 network in the endodermis development in both roots and shoots.

Overseas immigration of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), invading Korea and Japan in 2019

The fall armyworm(FAW),Spodoptera frugiperda(J.E.Smith),spread rapidly in Africa and Asia recently,causing huge economic losses in crop production.Fall armyworm caterpillars were first detected in South Korea and Japan in June 2019.Here,the migration timing and path for FAW into the countries were estimated by a trajectory simulation approach implementing the insect's flight behavior.The result showed that FAWs found in both South Korea and Japan were estimated to have come from eastern China by crossing the Yellow Sea or the East China Sea in 10–36 h in three series of migrations.In the first series,FAW moths that arrived on Jeju Island during 22–24 May were estimated to be from Zhejiang,Anhui and Fujian Provinces after 1–2 nights’flights.In the second series,it was estimated that FAW moths landed in southern Korea and Kyushu region of Japan simultaneously or successively during 5–9 June,and these moths mostly came from Guangdong and Fujian Provinces.The FAW moths in the third series were estimated to have immigrated from Taiwan Province onto Okinawa Islands during 19–24 June.During these migrations,southwesterly low-level jets extending from eastern China to southern Korea and/or Japan were observed in the northwestern periphery of the western Pacific Subtropical High.These results,for the first time,suggested that the overseas FAW immigrants invading Korea and Japan came from eastern and southern China.This study is helpful for future monitoring,early warning and the source control of this pest in the two countries.

Land suitability assessment for apple(Malus domestica)in the Republic of Korea using integrated soil and climate information,MLCM,and AHP

Apples(Malus domestica)are one of the major fruits cultivated in South Korea and worldwide.To both sustain the productivity of apple trees and preserve the land,a land suitability assessment has been conducted.Two methods were used to analyze land suitability,a Most-Limiting Characteristic Method(MLCM)and an Analytic Hierarchy Process(AHP)with integrated soil and climate information based on the FAO classification framework.The most-limiting characteristic analysis showed that almost all areas were classified as marginally suitable(S3)or not suitable(N),which together accounted for 94.54%of the land in the Republic of Korea.On the contrary,AHP showed that S1(34.1%)and S2(44.17%)account for the majority of the land.

Immune Sensor Xa21 Regulates Bacterial Leaf Blight Infection in Seven Rice Cultivars from Myanmar

Bacterial leaf blight(BLB)is a devastating disease of rice with the potential to reduce yield by up to 70%.In this study,we investigated the genetic foundation of Xa21-mediated resistance to BLB infection in seven different rice varieties from Myanmar.The varieties exhibited a variable phenotypic response at 14 d after infection(DAI)by Xoo strains K1 and K3a,among which,the variety Kayin Ma was classified as a moderately resistant(MR)variety,expressing Xa2,Xa4,xa5,xa13,and Xa21 genes.