[PC-0010] Evaluation of morphological characters, phytochemical contents and antioxidant activities of amaranth leaves

Weilan Li(Weilan Li),Eun Ae Yoo(Eun Ae Yoo),SooKyeong Lee(SooKyeong Lee),Hyung Jun Noh(Hyung Jun Noh),So Jeong Hwang(So Jeong Hwang),Kebede Taye Desta(Kebede Taye Desta ),Gi-An Lee(Gi-An Lee) 한국육종학회 2022 한국육종학회 공동학술발표집 Vol.2022 No.-

Occurrence of Bacterial Stem Rot of Ranunculus asiaticus Caused by Pseudomonas marginalis in Korea

Weilan Li,레오니드덴,김승한,이승열,정희영 한국식물병리학회 2018 식물병연구 Vol.24 No.2

In December 2016, stem rot symptoms were observed on Persian buttercup (Ranunculus asiaticus) plants in Chilgok, Gyeongbuk, Korea. In the early stage of the disease, several black spots appeared on the stem of infected plants. As the disease progressed, the infected stem cleaved and wilted. The causal agent was isolated from a lesion and incubated on Reasoner’s 2A (R2A) agar at 25°C. Total genomic DNA was extracted for phylogenetic analysis. Based on the 16S rRNA gene analysis, the isolated strain was found to belong to the genus Pseudomonas. To identify the isolated bacterial strain at the species level, the nucleotide sequences of the gyrase B (gyrB) and RNA polymerase D (rpoD) genes were obtained and compared with the sequences in the GenBank database. As the result, the causal agent of the stem rot disease was identified as Pseudomonas marginalis. To determine the pathogenicity of the isolated bacterial strain, it was inoculated into the stem of healthy R. asiaticus plant, the inoculated plant showed a lesion with the same characteristics as the naturally infected plant. Based on these results, this is the first report of bacterial stem rot on R. asiaticus caused by P. marginalis in Korea.

Spirosoma lituiforme sp. nov., isolated from soil

Weilan Li,이승열,박상규,김병오,Leonid N. Ten,정희영 한국미생물학회 2017 The journal of microbiology Vol.55 No.11

A Gram-staining-negative, non-motile, curved rod-shaped, aerobic bacterium, designated S1-2-4T, was isolated from soil in Jeollabuk-do province, Republic of Korea, and was characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain S1-2-4T was a member of the family Cytophagaceae and most closely related to ‘Spirosoma radiotolerans’ DG5A (97.2%), Spirosoma fluviale MSd3T (96.4%), and Spirosoma linguale DSM 74T (96.3%). The genomic DNA G + C content of strain S1-2-4T was 49.7 mol%. The major fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c), C16:1 ω5c, and C16:0, and the major polar lipid was phosphatidylethanolamine. MK-7 was the predominant respiratory quinone. Phenotypic and chemotaxonomic data supported the affiliation of strain S1-2-4T with the genus Spirosoma. DNA-DNA hybridization between strain S1-2-4T and ‘Spirosoma radiotolerans’ showed relatively low DNA-DNA relatedness (31%). Strain S1-2-4T could be distinguished from its closest phylogenetic neighbors based on its phenotypic, genotypic, and chemotaxonomic features. Therefore, strain S1-2-4T represents a novel member of the genus Spirosoma, for which the name Spirosoma lituiforme sp. nov. is proposed. The type strain is S1- 2-4T (= KCTC 52724T = JCM 32128T).

Rice 7-Hydroxymethyl Chlorophyll a Reductase Is Involved in the Promotion of Chlorophyll Degradation and Modulates Cell Death Signaling

Weilan Piao,한수현,Yasuhito Sakuraba,백남천 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.10

The loss of green coloration via chlorophyll (Chl) degradation typically occurs during leaf senescence. To date, many Chl catabolic enzymes have been identified and shown to interact with light harvesting complex II to form a Chl degradation complex in senescing chloroplasts; this complex might metabolically channel phototoxic Chl catabolic intermediates to prevent oxidative damage to cells. The Chl catabolic enzyme 7-hydroxymethyl Chl a reductase (HCAR) converts 7-hydroxymethyl Chl a (7-HMC a) to Chl a. The rice (Oryza sativa) genome contains a single HCAR homolog (OsHCAR), but its exact role remains unknown. Here, we show that an oshcar knockout mutant exhibits persistent green leaves during both dark-induced and natural senescence, and accumulates 7-HMC a and pheophorbide a (Pheo a) in green leaf blades. Interestingly, both rice and Arabidopsis hcar mutants exhibit severe cell death at the vegetative stage; this cell death largely occurs in a light intensity-dependent manner. In addition, 7-HMC a treatment led to the generation of singlet oxygen (1O2) in Arabidopsis and rice protoplasts in the light. Under herbicide-induced oxidative stress conditions, leaf necrosis was more severe in hcar plants than in wild type, and HCAR-overexpressing plants were more tolerant to re-active oxygen species than wild type. Therefore, in addition to functioning in the conversion of 7-HMC a to Chl a in senescent leaves, HCAR may play a critical role in protecting plants from high light-induced damage by preventing the accumu-lation of 7-HMC a and Pheo a in developing and mature leaves at the vegetative stage.

Loop-Mediated Isothermal Amplification for the Detection of Xanthomonas arboricola pv. pruni in Peaches

Weilan Li,이승열,Chang-Gi Back,Leonid N. Ten,Hee-Young Jung 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.6

To detect Xanthomonas arboricola pv. pruni, a loopmediated isothermal amplification (LAMP) detection method were developed. The LAMP assay was designed to test crude plant tissue without pre-extraction, or heating incubation, and without advanced analysis equipment. The LAMP primers were designed by targeting an ABC transporter ATP-binding protein, this primer set was tested using the genomic DNA of Xanthomonas and non-Xanthomonas strains, and a ladder product was generated from the genomic DNA of X. arboricola pv. pruni strain but not from 12 other Xanthomonas species strains and 6 strains of other genera. The LAMP conditions were checked with the healthy leaves of 31 peach varieties, and no reaction was detected using either the peach leaves or the peach DNA as a template. Furthermore, the high diagnostic accuracy of the LAMP method was confirmed with 13 X. arboricola pv. pruni strains isolated from various regions in Korea, with all samples exhibiting a positive reaction in LAMP assays. In particular, the LAMP method successfully detected the pathogen in diseased peach leaves and fruit in the field, and the LAMP conditions were proven to be a reliable diagnostic method for the specific detection and identification of X. arboricola pv. pruni in peach orchards.

Spirosoma humi sp. nov., Isolated from Soil in South Korea

Weilan, Li,Lee, Jae-Jin,Lee, Seung-Yeol,Park, Sangkyu,Ten, Leonid N.,Jung, Hee-Young Springer-Verlag 2018 Current microbiology Vol.75 No.3

<P>A Gram-stain-negative, non-motile, rod-shaped, aerobic bacterial strain, designated S7-4-1(T), was isolated from soil in Gyeongsangnam-do, South Korea and characterized using a polyphasic approach to determine its taxonomic position. Phylogenic analysis based on the 16S rRNA gene sequence showed that strain S7-4-1(T) belonged to the family Cytophagaceae and was most closely related to Spirosoma fluviale MSd3(T) (96.2%), 'Spirosoma radiotolerans' DG5A (96.0%), Spirosoma pulveris JSH5-14(T) (95.9%), and Spirosoma linguale DSM 74(T) (95.8%). The G+C content of the genomic DNA of the isolate was 49.0 mol%. The strain contained summed feature 3 (C-16:1 omega 7c/C-16:1 omega 6c; 41.0%), C-16:1 omega 5c (24.9%), and C-15:0 iso (9.3%) as the major fatty acids, menaquinone MK-7 as the predominant respiratory quinone, and phosphatidylethanolamine and an unidentified aminophospholipid as the main polar lipids, which supported its affiliation with the genus Spirosoma. The results of physiological and biochemical tests allowed the genotypic and phenotypic differentiation of the isolate from recognized Spirosoma species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S7-4-1(T) represents a novel species of the genus Spirosoma, for which the name Spirosoma humi sp. nov. is proposed. The type strain is S7-4-1(T) (= KCTC 52729(T) = JCM 32132(T)).</P>

Evaluation of agriculture traits, total oil content and fatty acid composition in seeds of 278 sesame genotypes

Weilan Li,Jungsook Sung,Eunae Yoo,Sojeong Hwang,Sookyeong Lee 한국육종학회 2023 한국육종학회 공동학술발표집 Vol.2023 No.-

Spirosoma pomorum sp. nov., isolated from apple orchard soil

Weilan Li,이승열,강인규,Leonid N. Ten,정희영 한국미생물학회 2018 The journal of microbiology Vol.56 No.2

A Gram-negative, motile, rod-shaped, aerobic bacterial strain, designated S7-2-11T, was isolated from apple orchard soil from Gyeongsangnam-do Province, Republic of Korea, and was characterized taxonomically using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain S7-2- 11T belongs to the family Cytophagaceae in phylum Bacteroidetes, and is closely related to Spirosoma luteolum 16F6ET (94.2% identity), Spirosoma knui 15J8-12T (92.7%), and Spirosoma linguale DSM 74T (91.0%). The G + C content of the genomic DNA of strain S7-2-11T was 49.8 mol%. Strain S7-2-11T contained summed feature 3 (C16:1 ω7c/C16:1 ω6c; 35.1%), C16:1 ω5c (22.4%), C15:0 iso (13.9%), and C17:0 iso 3-OH (10.6%) as major cellular fatty acids, and MK-7 as the predominant respiratory quinone. The main polar lipids were phosphatidylethanolamine, an unidentified aminophospholipid, and two unidentified polar lipids. Phenotypic and chemotaxonomic data supported the affiliation of strain S7-2-11T with the genus Spirosoma. The results of physiological and biochemical tests showed the genotypic and phenotypic differentiation of the isolate from recognized Spirosoma species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S7-2-11T represents a novel species of the genus Spirosoma, for which the name Spirosoma pomorum sp. nov. is proposed. The type strain is S7-2-11T (= KCTC 52726T = JCM 32130T).

First Report of Leptosphaerulina australis Isolated from Soil in Korea

( Weilan Li ),( Chang-gi Back ),( Seung-yeol Lee ),( Leonid N. Ten ),( Hee-young Jung ) 한국균학회 2018 韓國菌學會誌 Vol.46 No.4

The fungal strain KNU16-004 was isolated from a field soil sample collected in Seoul. The isolate was identified as Leptosphaerulina australis based on morphological characterization and phylogenetic analysis using the internal transcribed spacer (ITS), large subunit (LSU) rDNA regions, and β-tubulin (Tub2). This is the first report of Leptosphaerulina australis in Korea.

Transgenic expression of rice MYB102 (OsMYB102) delays leaf senescence and decreases abiotic stress tolerance in Arabidopsis thaliana

( Weilan Piao ),( Yasuhito Sakuraba ),( Nam-chon Paek ) 생화학분자생물학회(구 한국생화학분자생물학회) 2019 BMB Reports Vol.52 No.11

MYB-type transcription factors (TFs) play important roles in plant growth and development, and in the rapid responses to unfavorable environmental conditions. We recently reported the isolation and characterization of a rice (Oryza sativa) MYB TF, OsMYB102, which is involved in the regulation of leaf senescence by downregulating abscisic acid (ABA) biosynthesis and the downstream signaling response. Based on the similarities of their sequences and expression patterns, OsMYB102 appears to be a homolog of the Arabidopsis thaliana AtMYB44 TF. Since AtMYB44 is a key regulator of leaf senescence and abiotic stress responses, it is important to examine whether AtMYB44 homologs in other plants also act similarly. Here, we generated transgenic Arabidopsis plants expressing OsMYB102 (OsMYB102-OX). The OsMYB102-OX plants showed a delayed senescence phenotype during dark incubation and were more susceptible to salt and drought stresses, considerably similar to Arabidopsis plants overexpressing AtMYB44. Real-time quantitative PCR (RT-qPCR) revealed that, in addition to known senescence-associated genes, genes encoding the ABA catabolic enzymes AtCYP707A3 and AtCYP707A4 were also significantly upregulated in OsMYB102- OX, leading to a significant decrease in ABA accumulation. Furthermore, protoplast transient expression and chromatin immunoprecipitation assays revealed that OsMYB102 directly activated AtCYP707A3 expression. Based on our findings, it is probable that the regulatory functions of AtMYB44 homologs in plants are highly conserved and they have vital roles in leaf senescence and the abiotic stress responses. [BMB Reports 2019; 52(11): 653-658]