• 식물병연구
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• 제29권4호
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• pp.377-383
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• 2023

In 2020 and 2021, we surveyed diseases of three-leaf ladybell (Adenophora triphylla) plants grown in fields at two locations in Korea. During the disease surveys, severe leaf rot symptoms were observed on the young plants in Hongseong, and stem rot symptoms on the adult plants in Cheolwon. The incidence of leaf rot was 5-60%, and that of stem rot 1-10%. We obtained 6 fungal isolates each from the leaf rot lesions and the stem rot lesions. All the isolates were morphologically identified as Rhizoctonia solani. Anastomosis test and investigation of cultural features of the fungal isolates revealed that the isolates from the leaf rot lesions corresponded to R. solani AG-1(IB), and those from the stem rot lesions to R. solani AG-2-2(IIIB). Two isolates each of R. solani AG-1(IB) and AG-2-2(IIIB) were used for DNA sequence analysis and pathogenicity test to three-leaf ladybell plants through artificial inoculation. The anastomosis groups and cultural types of the R. solani isolates were confirmed by the sequence analysis. The pathogenicity tests revealed that the isolates of R. solani AG-1(IB) caused only leaf rot symptoms on the inoculated plants, and those of R. solani AG-2-2(IIIB) leaf rot and stem rot symptoms. The induced symptoms were similar to those observed in the fields investigated. Leaf and stem rot of three-leaf ladybell caused by the two anastomosis groups and cultural types of R. solani is first reported in this study.

• Mycobiology
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• 제51권5호
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• pp.313-319
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• 2023

During disease surveys of Angelica acutiloba plants in Korea, leaf spot symptoms were observed in a field in Andong in July 2019, and stem rot symptoms in vinyl greenhouses in Yangpyeong in April 2020. Incidence of leaf spot and stem rot of the plants ranged from 10 to 20% and 5 to 30%, respectively. Morphological and cultural characteristics of fungal isolates from the leaf spot and stem rot symptoms fitted into those of the genus Phoma. Molecular phylogenetic analyses of two single-spore isolates from the symptoms using concatenated sequences of LSU, ITS, TUB2, and RPB2 genes authenticated an independent cluster from other Didymella (anamorph: Phoma) species. Moreover, the isolates showed different morphological and cultural characteristics in comparison to closely related Didymella species. These discoveries confirmed the novelty of the isolates. Pathogenicity of the novel Didymella species isolates was substantiated on leaves and stems of A. acutiloba through artificial inoculation. Thus, this study reveals that Didymella acutilobae sp. nov. causes leaf spot and stem rot in Angelica acutiloba.

• Journal of Plant Biotechnology
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• 제33권2호
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• pp.111-115
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• 2006

Rot 3 유전자로 형질전환된 들깨를 이용하여 aromatic compounds, brightness, 안토시아닌 함량, leaf index를 조사하여 모본과의 품질적인 차이가 있는가를 조사하여 형질전환체의 안정성을 확보하기 위한 연구이다. Rot 3 유전자는 T1 과T2 세대에서 유전자발현이 되었으며, 형질전환이 확인된 개체는 주요 농업형질이 형질전환 되지 않은 들깨와는 차이가 없는 것으로 나타났다. 또한 aromatic compounds와 leaf brightness도 차이를 나타내지 않았다. 그러나 leaf index는 유전자의 표현을 나타내어 형질전환체와 형질전환되지 않은 들깨잎의 모양은 차이가 나타났다.

• Journal of Plant Biotechnology
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• 제38권4호
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• pp.285-292
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• 2011

식물 잎의 발달과정에서 heteroblasty는 외부 환경에 대한 식물의 형태적 적응 방법을 매우 잘 반영하며 이에 따른 변화는 기관의 최종 형태와 크기에 영향을 미친다. Heteroblasty를 나타내는 인자 중에서 leaf index는 단엽식물의 잎의 최종 모양과 크기를 나타내는 대표적인 인자이다. Leaf index는 결국 잎몸에서의 세포 증식과 세포 신장의 두 요인에 의해 결정된다. 비록 세포의 증식과 신장을 조절하는 유전자와 조절 기작들이 연구되고 있으나 큰 청사진을 제시하기에는 아직 미흡하다. 본 연구에서는 발달과정 중 잎의 leaf index 조절에 관여하는 유전자를 밝히고 그 조절 기작을 알아내기 위하여 애기장대 돌연변이체를 이용한 분자유전학적, 생리학적인 실험을 수행하였다. 잎과 잎 세포가 커지는 돌연변이체인 macrophylla (mac)를 선발하여 잎의 확장과정과 leaf index의 이상으로 인해 잎 기관의 모양뿐 만 아니라 heteroblasty에 변화가 발생했다는 사실을 밝혀냈다. 또한 이 돌연변이체는 기존에 알려진 ROTUNDIFOLIA3 (ROT3) 유전자의 점 돌연변이에 의해 일어났다고 판명되었고 mac/rot3-5로 명명되었다. 브라시노스테로이드 처리로 인해 ROT3 유전자의 발현이 음성 되먹임 저해를 받는 것으로 보아 ROT3 유전자가 브라시노스테로이드 생합성에 관여함을 제시하였다. 또한 암상태에서 ROT3 유전자의 발현이 증가하며, mac/rot3-5 돌연변이체가 야생형보다 암반응이 약하게 나타났다. 이러한 분석 결과를 토대로 본 논문은 ROT3 유전자가 잎의 확장과정에서 잎의 leaf index 조절과 고유한 heteroblasty의 정립에 중요한 역할을 수행하며, 브라시노스테로이드 호르몬의 조절을 통하여 음지회피성과 같은 환경조절반응을 수행하고 있다는 새로운 사실을 제시하였다.

• 식물병연구
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• 제28권2호
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• pp.108-111
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• 2022

In December 2020, stem and leaf rot symptoms in small-fruited tomato (Solanum lycopersicum) plants were observed in a farmer's vinyl greenhouse located in Pyeongtaek, Gyeonggi Province, Korea. The incidence of diseased plants in the vinyl greenhouse was 2-6%. Seven single-spore isolates of Phoma sp. were obtained from the diseased stems and leaves. All the isolates were identified as Boeremia linicola based on the cultural, morphological and molecular characteristics. Two isolates of B. linicola were tested for pathogenicity on stems and leaves of small-fruited tomato and large-fruited tomato using artificial inoculation. All the tested isolates caused stem and leaf rot symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the vinyl greenhouse investigated. This is the first report of B. linicola causing stem and leaf rot in tomato.

• The Plant Pathology Journal
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• 제33권4호
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• pp.434-439
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• 2017

Incidence rates of diseases in kiwiberry orchards were investigated monthly from late June to late September in Gwangyang and Boseong in 2015 and 2016. The impact of postharvest fruit rot was investigated during ripening after harvest. Bacterial canker was only observed on one single tree in 2015, but black rot, powdery mildew, leaf spot and blight, and postharvest fruit rot diseases were problematic throughout the study period in both 2015 and 2016. Incidence rates of the diseases varied with kiwiberry cultivar, region and sampling time. Incidence rates of powdery mildew, leaf spot and blight diseases increased significantly during the late growing stages near fruit harvest, while black rot peaked in late August. Incidence rate of postharvest fruit rot on fruit without fruit stalks was less than half of fruit with fruit stalks, regardless of kiwiberry cultivars. Among the four cultivars, Mansu was relatively resistant to black rot and postharvest fruit rot diseases. In our knowledge, this is the first report of various potential pathogens of kiwiberry in Korea.

• The Plant Pathology Journal
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• 제34권3호
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• pp.218-235
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• 2018

Plant growth promoting rhizobacteria and endophytic bacteria were isolated from different varieties of turmeric (Curcuma longa L.) from South India. Totally 50 strains representing, 30 PGPR and 20 endophytic bacteria were identified based on biochemical assays and 16S rDNA sequence analysis. The isolates were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric, by dual culture and liquid culture assays. Results revealed that only five isolates of PGPR and four endophytic bacteria showed more than 70% suppression of test pathogens in both assays. The SEM studies of interaction zone showed significant ultrastructural changes of the hyphae like shriveling, breakage and desication of the pathogens by PGPR B. cereus (RBacDOB-S24) and endophyte P. aeruginosa (BacDOB-E19). Selected isolates showed multiple Plant growth promoting traits. The rhizome bacterization followed by soil application of B. cereus (RBacDOB-S24) showed lowest Percent Disease Incidence (PDI) of rhizome rot and leaf blight, 16.4% and 15.5% respectively. Similarly, P. aeruginosa (BacDOB-E19) recorded PDI of rhizome rot (17.5%) and leaf blight (17.7%). The treatment of these promising isolates exhibited significant increase in plant height and fresh rhizome yield/plant in comparison with untreated control under greenhouse condition. Thereby, these isolates can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.

• Mycobiology
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• 제40권4호
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• pp.268-271
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• 2012

In June 2012, leaf spot and stem rot were observed on Wilford Swallowwort plants grown in Cheonan, Korea. Three fungal isolates obtained from the diseased leaves and stems were identified as Stemphylium lycopersici, based on morphological, cultural, and molecular characteristics and pathogenicity. This is the first report of leaf spot and stem rot on Wilford Swallowwort caused by S. lycopersici.

• Journal of Plant Biotechnology
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• 제5권3호
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• pp.137-142
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• 2003

The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wildtype ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2003년도 식물바이오벤처 페스티발
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• pp.49-55
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• 2003

The morphology of the leaves and the flowers of angiosperms exhibit remarkable diversity. One of the factors showing the greatest variability of leaf organs is the leaf index, namely, the ratio of leaf length to leaf width. In some cases, different varieties of a single species or closely related species can be distinguished by differences in leaf index. To some extent, the leaf index reflects the morphological adaptation of leaves to a particular environment. In addition, the growth of leaf organs is dependent on the extent of the expansion of leaf cells and on cell proliferation in the cellular level. The rates of the division and enlargement of leaf cells at each stage contribute to the final shape of the leaf, and play important roles throughout leaf development. Thus, the control of leaf shape is related to the control of the shape of cells and the size of cells within the leaf. The shape of flower also reflects the shape of leaf, since floral organs are thought to be a derivative of leaf organs. No good tools have been available for studies of the mechanisms that underlie such biodiversity. However, we have recently obtained some information about molecular mechanisms of leaf morphogenesis as a result of studies of leaves of the model plant, Arabidopsis thaliana. For example, the ANGUSTIFOLIA (AN) gene, a homolog of animal CtBP genes, controls leaf width. AN appears to regulate the polar elongation of leaf cells via control of the arrangement of cortical microtubules. By contrast, the ROTUNDIFOLIA3 (ROT3) gene controls leaf length via the biosynthesis of steroid(s). We provide here an overview of the biodiversity exhibited by the leaf index of angiosperms. Taken together, we can discuss on the possibility of the control of the shapes and size of plant organs by transgenic approaches with the results from basic researches. For example, transgenic plants that overexpressed a wild-type ROT3 gene had longer leaves than parent plants, without any changes in leaf width. Thus, The genes for leaf growth and development, such as ROT3 gene, should be useful tools for the biodesign of plant organs.