• Title/Summary/Keyword: plant physiology

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AP2/EREBP Transcription Factors in Rice

  • Kim, Yun-Ju;Jung, Eui-Whan;Hwang, Seon-Hee;Go, Seong-Joo;Hwang, Duk-Ju
    • The Plant Pathology Journal
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    • v.20 no.1
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    • pp.41-45
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    • 2004
  • Plants have the ability to defend themselves against pathogens by activating a series of defense responses. SA is known to be a signal molecule in plant defense responses. Nevertheles, SA is not the only one signal mediating defense responses. In addition to SA, ethylene and jasmonic acid have also been known to mediate plant defense responses against pathogens. The activation of a series of plant defense responses is known to be through varieties of transcription factors. Specially AP2/EREBP transcription factors are involved in ethylene mediated defense signaling. In this review, recent progress on AP2/EREBP transcription factors in arabidopsis, tomato and tobacco and a few of AP2/ EREBP transcription factors in rice related to biotic stresses will be discussed.

Mayamaea vietnamica sp. nov.: a new, terrestrial diatom (Bacillariophyceae) species from Vietnam

  • Kezlya, Elena;Glushchenko, Anton;Kociolek, John Patrick;Maltsev, Yevhen;Martynenko, Nikita;Genkal, Sergei;Kulikovskiy, Maxim
    • ALGAE
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    • v.35 no.4
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    • pp.325-335
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    • 2020
  • A new diatom species, Mayamaea vietnamica sp. nov., is described from Cát Tiên National Park in Vietnam. This species was discovered and described from soil samples. Algae from soil ecosystems in Vietnam are almost unknown. The new species is described on the basis of an integrated approach with molecular and morphological data, and comparison with similar species. In terms of molecular data, 18S rDNA (including V4 domain), and partial rbcL plastid genes show M. vietnamica sp. nov. is most closely related to M. terrestris N. Abarca and R. Jahn, and together they form a monophyletic group relative to other members of the genus. M. vietnamica sp. nov. differs from other species in the genus by the number of striae and areolae in 10 ㎛, number of areolae per stria, as well as shape and presence or absence of axial and central areas.

Cotton GhKCH2, a Plant-specific Kinesin, is Low-affinitive and Nucleotide-independent as Binding to Microtubule

  • Xu, Tao;Sun, Xuewei;Jiang, Shiling;Ren, Dongtao;Liu, Guoqin
    • BMB Reports
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    • v.40 no.5
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    • pp.723-730
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    • 2007
  • Kinesin is an ATP-driven microtubule motor protein that plays important roles in control of microtubule dynamics, intracellular transport, cell division and signal transduction. The kinesin superfamily is composed of numerous members that are classified into 14 subfamilies. Animal kinesins have been well characterized. In contrast, plant kinesins have not yet to be characterized adequately. Here, a novel plant-specific kinesin gene, GhKCH2, has been cloned from cotton (Gossypium hirsutum) fibers and biochemically identified by prokaryotic expression, affinity purification, ATPase activity assay and microtubule-binding analysis. The putative motor domain of GhKCH2, $M_{396-734}$ corresponding to amino acids Q396-N734 was fused with 6$\times$His-tag, soluble-expressed in E. coli and affinity-purified in a large amount. The biochemical analysis demonstrated that the basal ATPase activity of $M_{396-734}$ is not activated by $Ca^{2+}$, but stimulated 30-fold max by microtubules. The enzymatic activation is microtubule-concentration-dependent, and the concentration of microtubules that corresponds to half-maximum activation was about 11 ${\mu}M$, much higher than that of other kinesins reported. The cosedimentation assay indicated that $M_{396-734}$ could bind to microtubules in vitro whenever the nucleotide AMP-PNP is present or absent. As a plant-specific microtubule-dependent kinesin with a lower microtubule-affinity and a nucleotide-independent microtubule-binding ability, cotton GhKCH2 might be involved in the function of microtubules during the deposition of cellulose microfibrils in fibers or the formation of cell wall.

Virus-like Particles and Cellular Changes in Plants Infected with Sweetpotato Viruses

  • Sim, Jeong-Gu;Valverde, Rodrigo;Clark, Christopher;Chun, Se-Chul
    • The Plant Pathology Journal
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    • v.24 no.1
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    • pp.36-45
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    • 2008
  • Studies with the transmission electron microscope were used to detect and attempt to identify viruses infecting sweetpotato (Ipomoea batatas) and other Ipomoea species. Flexuous-rods, short curved-rods, and spherical virus-like particles were observed in cells of symptomatic plants. Also, various cytopathic changes such as crystals, vesicles, fibril structures, and cylindrical inclusions were observed. The present study showed that some of these cytopathic changes were associated with some viral groups, which might be helpful in diagnosis.

Roads to Construct and Re-build Plant Microbiota Community

  • Kim, Da-Ran;Kwak, Youn-Sig
    • The Plant Pathology Journal
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    • v.38 no.5
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    • pp.425-431
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    • 2022
  • Plant microbiota has influenced plant growth and physiology significantly. Plant and plant-associated microbes have flexible interactions that respond to changes in environmental conditions. These interactions can be adjusted to suit the requirements of the microbial community or the host physiology. In addition, it can be modified to suit microbiota structure or fixed by the host condition. However, no technology is realized yet to control mechanically manipulated plant microbiota structure. Here, we review step-by-step plant-associated microbial partnership from plant growth-promoting rhizobacteria to the microbiota structural modulation. Glutamic acid enriched the population of Streptomyces, a specific taxon in anthosphere microbiota community. Additionally, the population density of the microbes in the rhizosphere was also a positive response to glutamic acid treatment. Although many types of research are conducted on the structural revealing of plant microbiota, these concepts need to be further understood as to how the plant microbiota clusters are controlled or modulated at the community level. This review suggests that the intrinsic level of glutamic acid in planta is associated with the microbiota composition that the external supply of the biostimulant can modulate.

Influence of the Donor Side of Photosystem II on the Photogeneration of Superoxide Radicals and Chlorophyll a Fluorescence

  • Weng, Jun;Zhang, Suping;Pan, Jingxi;Jinxing, Chen;Xu, Chunhe
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.385-387
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    • 2002
  • Direct EPR evidence of the photo-generation of superoxide radicals ( $O_2$$^{-.}$) was obtained by using spin trapping techniques in spinach photosystem II (PSII) membranes. $O_2$$^{-.}$ was detected by following the formation of 5-diethoxyphosphoryl-5-methyl-1 -pyrroline-N-oxide (DEPMPO) superoxide adducts, DEPMPO-OOH. The significant increase of the EPR signal amplitude of DEPMPO-OOH in N$H_2O$H-, CaC $l_2$- and NaCl-treated PSII membranes showed that the oxygen-evolving system has a close relation to the $O_2$$^{-.}$ production. PSII membranes with inactivated donor side could not prevent the $O_2$$^{-.}$ production efficiently. Treatments on PSII donor side also influence the maximum level and the kinetics of Chlorophyll (Chi) a fluorescence. Results suggested that manganese cluster and extrinsic proteins might affect Chi a fluorescence in ways different from that happens at the acceptor side of PSII.SII.SII.

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