• Title/Summary/Keyword: Plant cell

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3-Methylthiopropionic Acid of Rhizoctonia solani AG-3 and Its Role in the Pathogenicity of the Fungus

  • Kankam, Frederick;Long, Hai-Tao;He, Jing;Zhang, Chun-hong;Zhang, Hui-Xiu;Pu, Lumei;Qiu, Huizhen
    • The Plant Pathology Journal
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    • v.32 no.2
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    • pp.85-94
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    • 2016
  • Studies were conducted to determine the role of 3-methylthioproprionic acid (MTPA) in the pathogenicity of potato stem canker, Rhizoctonia solani, and the concentrations required to inhibit growth of R. solani under laboratory and plant house-based conditions. The experiments were laid out in a completely randomized design with five treatments and five replications. The treatments were 0, 1, 2, 4, and 8 mM concentrations of MTPA. The purified toxin exhibited maximal activity at pH 2.5 and $30^{\circ}C$. MTPA at 1, 2, 4, and 8 mM levels reduced plant height, chlorophyll content, haulm fresh weight, number of stolons, canopy development, and tuber weight of potato plants, as compared to the control. MTPA significantly affected mycelial growth with 8 mM causing the highest infection. The potato seedlings treated with MTPA concentrations of 1.0-8.0 mM induced necrosis of up to 80% of root system area. Cankers were resulted from the injection of potato seedling stems with 8.0 mM MTPA. The results showed the disappearance of cell membrane, rough mitochondrial and cell walls, change of the shape of chloroplasts, and swollen endoplasmic reticulum. Seventy-six (76) hours after toxin treatment, cell contents were completely broken, cytoplasm dissolved, and more chromatin were seen in the nucleus. The results suggested that high levels of the toxin concentration caused cell membrane and cytoplasm fracture. The integrity of cellular structure was destroyed by the phytotoxin. The concentrations of the phytotoxin were significantly correlated with pathogenicity and caused damage to the cell membrane of potato stem base tissue.

Overexpression of ginseng patatin-related phospholipase pPLAIIIβ alters the polarity of cell growth and decreases lignin content in Arabidopsis

  • Jang, Jin Hoon;Lee, Ok Ran
    • Journal of Ginseng Research
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    • v.44 no.2
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    • pp.321-331
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    • 2020
  • Background: The patatin-related phospholipase AIII family (pPLAIIIs) genes alter cell elongation and cell wall composition in Arabidopsis and rice plant, suggesting diverse commercial purposes of the economically important medicinal ginseng plant. Herein, we show the functional characterization of a ginseng pPLAIII gene for the first time and discuss its potential applications. Methods: pPLAIIIs were identified from ginseng expressed sequence tag clones and further confirmed by search against ginseng database and polymerase chain reaction. A clone showing the highest homology with pPLAIIIβ was shown to be overexpressed in Arabidopsis using Agrobacterium. Quantitative polymerase chain reaction was performed to analyze ginseng pPLAIIIβ expression. Phenotypes were observed using a low-vacuum scanning electron microscope. Lignin was stained using phloroglucinol and quantified using acetyl bromide. Results: The PgpPLAIIIβ transcripts were observed in all organs of 2-year-old ginseng. Overexpression of ginseng pPLAIIIβ (PgpPLAIIIβ-OE) in Arabidopsis resulted in small and stunted plants. It shortened the trichomes and decreased trichome number, indicating defects in cell polarity. Furthermore, OE lines exhibited enlarged seeds with less number per silique. The YUCCA9 gene was downregulated in the OE lines, which is reported to be associated with lignification. Accordingly, lignin was stained less in the OE lines, and the expression of two transcription factors related to lignin biosynthesis was also decreased significantly. Conclusion: Overexpression of pPLAIIIβ retarded cell elongation in all the tested organs except seeds, which were longer and thicker than those of the controls. Shorter root length is related to auxinresponsive genes, and its stunted phenotype showed decreased lignin content.

Cell death phenotype of vacuole Ca2+-ATPase11 (ACA11) transgenic plant in Arabidopsis (애기장대에서 액포막 존재 Ca2+-ATPase11 (ACA11) 형질전환제의 세포사멸 표현형 분석)

  • Lee, Sang-Min;Hoang, My-HanhThi;Kim, Kyung-Eun;Chung, Woo-Sik
    • Journal of Plant Biotechnology
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    • v.36 no.1
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    • pp.59-63
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    • 2009
  • Calcium ion ($Ca^{2+}$) is thought to play the important role as a second messenger for signal transduction that results in various physiological responses to cope with developmental programs and environmental changes in plant. In plant cells, the central vacuole functions as a major calcium store, which is important for both signal transduction and preventing cytotoxicity. Although there is evidence for the biochemical characterizations of a calmodulin-regulated $Ca^{2+}$-ATPase (ACA11) localized to vacuole membrane, the biological function to ACA11 in plant has not been verified. In this study, we show that the cell death as the hypersensitive response (HR) in mature leaves is induced in transgenic plant of a vacuole ACA-type $Ca^{2+}$-ATPase, ACA11. Evidence that cell death phenotype is the result of ACA11 gene silencing is provided by Western blot assay using membrane fraction proteins extracted from transgenic plant. The 3, 3'-diaminobenzidine (DAB) staining study provides that the cell death is caused by the increase of reactive oxygen species (ROS) in mature leaves of transgenic plants.

Plant Protoplant Culture and Somatic Cell Hybridization (원형질배양과 체세포잡종)

  • 한창열
    • Journal of Plant Biology
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    • v.15 no.3
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    • pp.14-18
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    • 1972
  • This paper includes a review on recent development on protoplast culture, regeneraton of plant from protoplast, and fusion of isolated protoplasts, and also describes the possibility of obtaining interspecific hybrid plants through asexual fusion of protoplasts of cells from distantly related plants which are not crossed by the ordinary sexual method.

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