4,439 research outputs found
Studies on lateral root formation in rice: the effects of methyl jasmonate and cobalt chloride
No full text 本論文係利用水稻台中在來一號 (Oryza sativa L. cv. Taichung Native 1, TN1)探討甲基茉莉酸鹽 [methyl jasmonate (MJ)]與氯化鈷 (CoCl2)對水稻側根形成之影響，同時探討一氧化氮(NO)、heme oxygenase (HO)與Ca2+於其中所扮演的角色。
MJ處理會增加水稻側根的數目與NO之形成，同時處理MJ以及NO的清除劑carboxy-2-phenyl-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO)後，會降低水稻側根數目與NO之形成。利用nitrate reductase (NR)抑制劑tungstate (Tu)可完全抑制MJ誘導水稻側根與NO之形成，而使用nitric oxide synthase (NOS)抑制劑NG-nitro-L-arginine methyl ester hydrochloride (L-NAME)則無法完全抑制MJ誘導側根與NO形成，顯示MJ促進NO形成是與NR的活性相關。經NO螢光染色結果，可清楚的看到MJ誘導NO產生與側根根原基形成的位置一致。由此推測MJ所引起的側根發育可能是藉由NO作為傳遞訊息分子。
MJ處理會提升血紅素氧化酵素 (heme oxygenase, HO; EC1.14.99.3)的活性。從時間軸來看，HO活性的增加早於側根出現之前，暗示MJ可能是藉由影響HO活性上升，進而誘導側根形成。處理HO抑制劑zinc protoporphyrinIX (ZnPPIX)以及CO清除劑hemoglobin (Hb)會顯著降低MJ所增加HO活性及側根的數目。外加HO的另一個產物biliverdin (BV)後發現，BV不但促進水稻側根數目，亦使得HO的活性增加。此外，我們亦發現了Ca2+會影響側根之發育，處理Ca2+的螯合物、通道抑制劑及攜鈣素 (camodulin)的拮抗劑均會抑制側根之形成。
CoCl2處理亦可增加水稻側根數目，並提升HO的活性。從時間軸來看，HO活性的增加早於側根形成，暗示CoCl2可能是藉由影響HO活性上升，進而誘導側根形成。處理HO抑制劑ZnPPIX以及一氧化碳清除劑Hb會顯著降低CoCl2所增加HO活性及側根的數目。處理CoCl2不會增加H2O2含量，同時處理過氧化氫 (H2O2)清除劑ascorbic acid (AsA) 亦不影響CoCl2誘導的HO活性及側根數目，指出CoCl2所造成之影響與活化氧族 (reactive oxygen species)無關。In this thesis, the role of nitric oxide (NO), heme oxygenase (HO) and Ca2+ in regulating methyl jasmonate (MJ)-induced lateral roots (LR) formation in rice cultivar TN1 (Oryza sativa L. cv. Taichung Native 1) was examined. Also included in this thesis is the possible mechanism of CoCl2-promoted LR formation in rice.
Application of MJ to rice seedlings promoted LR formation and NO production. Treatment with MJ and NO specific scavenger carboxy-2-phenyl-4, 4, 5, 5- tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) reduced MJ-induced LR formation and NO production. NO was detected by the specific fluorescence probe, 4-amino-5- ethylamino-2’, 7’-difluoroflorescein diacetate (DAF-FM DA). NR inhibitor, sodium tungstates (Tu), completely inhibited MJ-induced LR formation and NO fluorescence. However, nitric oxide synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) slightly reduced MJ-induced LR formation and NO generation, suggesting that NR activity is involved in MJ-increased NO production in rice roots. Moreover, the fluorescence of the longitudinal section of roots showed that NO production induced by MJ was localized in the LR primodia. It suggests that NO is a signal molecule involved in the regulation of MJ-induced LR formation.
MJ was able to increased rice seedlings HO activity. The time-course analyses of HO activity and LR formation clearly indicated that MJ-induced HO activity occurred before LR formation. Treatment with zinc protoporphyrinIX (ZnPPIX), an HO inhibitor, and hemoglobin (Hb), a CO scavenger, blocked MJ-induced LR formation and HO activity. Moreover, BV, another product of HO, also triggered LR development and HO activity. Pretreatment of Ca2+ chelators, channel blockers and camodulin antagonists inhibited MJ-promoted LR formation, but had no effect on MJ-induced HO activity.
Rice seedlings treated with CoCl2 also could promoted LR formation and HO activity. The time-course analyses of HO activity and LR formation clearly indicated that CoCl2-induced HO activity occurred before LR formation. ZnPPIX and Hb were able to reduced HO activity and the number of LR. CoCl2 (20 μM) had no effect on H2O2 production. Moreover, ascorbic acid (AsA) had no effect on CoCl2-induced HO activity and the LR number. It appears that reactive oxygen species (ROS) is not involved in the CoCl2-induced LR formation
Diffuse mesothelin expression correlates with prolonged patient survival in ovarian serous carcinoma.
No full textDoxorubicin delivery by polyamidoamine dendrimer conjugation and photochemical internalization for cancer therapy.
No full textCoexistence of autonomic and somatic mechanisms in the pressor areas of medulla in cats.
No full textSelf-compression of 4.9 µm pulses to sub-40 fs with 2 mJ energy in Zinc Sulfide
No full textNonlinear self-compression of few-cycle multi-mJ pulses at 4.9 µm in ZnS is presented. 80 fs input pulses are compressed to 37 fs with 2.1 mJ energy at a 1 kHz repetition rate. © 2024 The Author(s
Correction to: Chamoun et al., Bacterial pathogenesis and interleukin-17: interconnecting mechanisms of immune regulation, host genetics, and microbial virulence that influence severity of infection
No full textChamoun MN, Blumenthal A, Sullivan MJ, Schembri MA, Ulett GC. 2018. Bacterial pathogenesis and interleukin-17: interconnecting mechanisms of immune regulation, host genetics, and microbial virulence that influence severity of infection. Critical Reviews in Microbiology. https://doi.org/10.1080/1040841X.2018.1426556.
When the above article was first published online, the below three corrections were missed.
The author ‘Antje Blumenthal’ was wrongly affiliated to the affiliation “cSchool of Chemistry and Molecular Biosciences, and Australian Infectious Disease Research Centre, The University of Queensland, Brisbane, Australia”. Now this affiliation has been removed for this author.
The affiliation ‘bTranslational Research Institute, The University of Queensland Diamantina Institute, Woolloongabba, Australia’ of the author ‘Antje Blumenthal’ should read ‘bThe University of Queensland Diamantina Institute, Translational Research Institute, Brisbane, Australia’.
In Table 3, the sentence ‘Benefit of manipulating IL-17 levels to improve immunization strategies M. tuberculosis’ should read “Benefit of manipulating IL-17 levels to improve immunization strategies against M. tuberculosis”.No Full Tex
Generation of 22-mJ, 2.0-ps Pulses from a 1-kHz Ho:YLF Regenerative Chirped Pulse Amplifier
No full textWe report a CW-pumped Ho:YLF regenerative amplifier (RA) delivering pulses with 22.5-mJ energy and 2.0-ps duration at 1 kHz. The RA emitting at 2051 nm is broadband-seeded and implemented in a chirped pulse amplification system. © 2024 The Author(s
Structural Analysis of Chi1 Chitinase from Yen-Tc: The Multisubunit Insecticidal ABC Toxin Complex of Yersinia entomophaga.
No full textYersinia entomophaga MH96 is a native New Zealand soil bacterium that secretes a large ABC-type protein toxin complex, Yen-Tc, similar to those produced by nematode-associated bacteria such as Photorhabdus luminescens. Y. entomophaga displays an exceptionally virulent pathogenic phenotype in sensitive insect species, causing death within 72 h of infection. Because of this phenotype, there is intrinsic interest in the mechanism of action of Yen-Tc, and it also has the potential to function as a novel class of biopesticide. We have identified genes that encode chitinases as part of the toxin complex loci in Y. entomophaga MH96, P. luminescens, Photorhabdus asymbiotica and Xenorhabdus nematophila. Furthermore, we have shown that the secreted toxin complex from Y. entomophaga MH96 includes two chitinases as an integral part of the complex, a feature not described previously in other ABC toxins and possibly related to the severe disease caused by this bacterium. We present here the structure of the Y. entomophaga MH96 Chi1 chitinase, determined by X-ray crystallography to 1.74 Å resolution, and show that a ring of five symmetrically arranged lobes on the surface of the Yen-Tc toxin complex structure, as determined by single-particle electron microscopy, provides a good fit to the Chi1 monomer. We also confirm that the isolated chitinases display endochitinase activity, as does the complete toxin complex
Pure-rotational 1D-CARS spatiotemporal thermometry with a single regenerative amplifier system
No full textWe report spatiotemporal pure-rotational coherent anti-Stokes Raman spectroscopy (CARS) in a one-dimensional imaging arrangement obtained with a single ultrafast regenerative amplifier system. The femtosecond pump/Stokes photon pairs, used for impulsive excitation, are delivered by an external compressor operating on a ∼35% beam split of the uncompressed amplifier output (2.5 mJ/pulse). The picosecond 1.2 mJ probe pulse is produced via the second-harmonic bandwidth compression (SHBC) of the ∼65% remainder of the amplifier output (4.5 mJ/pulse), which originates from the internal compressor. The two pump/Stokes and probe pulses are spatially, temporally, and repetition-wise correlated at the measurement, and the signal generation plane is relayed by a wide-field coherent imaging spectrometer onto the detector plane, which is refreshed at the same repetition rate as the ultrafast regenerative amplifier system. We demonstrate 1 kHz cinematographic 1D-CARS gas-phase thermometry across an unstable premixed methane/air flame-front, achieved with a single-shot precision <1% and accuracy <3%, 1.4 mm field of view, and an excellent <20 µm line-spread function.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Flight Performance and Propulsio
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