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Yamamoto S, Tomita H, Terabayashi R, Yoshida K, Nakanishi K, Furukawa T, Kamada K, Yoshikawa A. In-vivo imaging of a mouse by detecting bremsstrahlung X-rays from 14C using a La-GPS imaging system. J NUCL SCI TECHNOL 2022. [DOI: 10.1080/00223131.2022.2050319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Seiichi Yamamoto
- Department of Integrated Health Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hideki Tomita
- Department of Energy Engineering, Nagoya University, Graduate School of Engineering, Nagoya, Japan
| | - Ryohei Terabayashi
- Department of Energy Engineering, Nagoya University, Graduate School of Engineering, Nagoya, Japan
| | - Kenji Yoshida
- Drug Development Solutions Center, Sekisui Medical Co. Ltd., Tokai, Japan
| | - Kouhei Nakanishi
- Department of Integrated Health Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takako Furukawa
- Department of Integrated Health Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kei Kamada
- New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Japan
| | - Akira Yoshikawa
- New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Japan
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Welker S, Pierre M, Santiago JP, Dutt M, Vincent C, Levy A. Phloem transport limitation in Huanglongbing-affected sweet orange is dependent on phloem-limited bacteria and callose. TREE PHYSIOLOGY 2022; 42:379-390. [PMID: 34617106 DOI: 10.1093/treephys/tpab134] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 10/01/2021] [Indexed: 05/11/2023]
Abstract
Huanglongbing (HLB), caused by Candidatus `Liberibacter asiaticus' (CLas), is a phloem-limited disease that disrupts citrus production in affected areas. In HLB-affected plants, phloem sieve plate pores accumulate callose, and leaf carbohydrate export is reduced. However, whether HLB causes a reduction in carbohydrate phloem translocation speed and the quantitative relationships among callose, CLas population and phloem translocation are still unknown. In this work, a procedure was developed to concurrently measure sugar transport, callose deposition and relative pathogen population at different locations throughout the stem. Increasing quantities of CLas genetic material were positively correlated with quantity and density of callose deposits and negatively correlated with phloem translocation speed. Callose deposit quantity was position and rootstock dependent and was negatively correlated with phloem translocation speed, suggesting a localized relationship. Remarkably, callose accumulation and phloem translocation disruption in the scion were dependent on rootstock genotype. Regression results suggested that the interaction of Ct values and number of phloem callose depositions, but not their size or density, explained the effects on translocation speed. Sucrose, starch and sink 14C label allocation data support the interpretation of a transport pathway limitation by CLas infection. This work shows that the interaction of local accumulation of callose and CLas affects phloem transport. Furthermore, the extent of this accumulation is attenuated by the rootstock and provides important information about the disease mechanism of phloem-inhabiting bacteria. Together, these results constitute the first example of a demonstrated transport limitation of phloem function by a microbial infection.
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Affiliation(s)
- Stacy Welker
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Myrtho Pierre
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA
| | - James P Santiago
- Plant Resilience Institute and MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Manjul Dutt
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA
- Department of Horticulture, University of Florida, Gainesville, FL 32611, USA
| | - Christopher Vincent
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA
- Department of Horticulture, University of Florida, Gainesville, FL 32611, USA
| | - Amit Levy
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
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Li SY, Vincent C. Root:shoot balance controls flush phenology and carbohydrate translocation dynamics in citrus (Citrus x sinensis) trunk. PHYSIOLOGIA PLANTARUM 2022; 174:e13601. [PMID: 34796913 DOI: 10.1111/ppl.13601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/01/2021] [Accepted: 11/17/2021] [Indexed: 06/13/2023]
Abstract
Flush shoot growth presents a fluctuation pattern alternating with root growth. The cyclic pattern determines the balance of root:shoot and can affect the direction and speed of carbohydrate translocation during the vegetative growth period. In this study, we used water deficit to limit corresponding growth in sweet orange (Citrus x sinensis) "OLL 4" grafted on "US-942" rootstock, and then observed the changes of translocation dynamics between two flush statuses. Our first hypothesis was that water deficit would reduce root growth and extend the root growth phase during the growth cycle, delaying the following flush. We then tested the related second hypothesis that shoot flushes would switch the direction and slow the speed of carbohydrate transport due to fluctuation between single and dual sinks. After recovery from a severe deficit, the flush was synchronized and emerged within 2 weeks. Mild and moderate water-deficit plants showed a delayed new flush. Next, we used a 14 C-labeling method to test whether translocation was affected by the presence of new flush. Basipetal translocation was dominant, but the new flush increased the likelihood of acropetal translocation. Translocation speeds were not different in both directions regardless of flushing status, though speed estimates were highly variable, even though 14 C export from the source leaf increased when new flush was present. The results suggest that flush timing across an environmental gradient is governed by source-sink dynamics. The presence of new flush altered the direction of photoassimilate translocation and rate of leaf export, but stem transport speeds were not distinguishably different.
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Affiliation(s)
- Sheng-Yang Li
- Horticultural Sciences Department, Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, USA
| | - Christopher Vincent
- Horticultural Sciences Department, Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, USA
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Nakanishi K, Yamamoto S. Monte Carlo simulation of the bremsstrahlung X-rays emitted from H-3 and C-14 for the in-vivo imaging of small animals. Appl Radiat Isot 2020; 160:109136. [PMID: 32351228 DOI: 10.1016/j.apradiso.2020.109136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 01/22/2020] [Accepted: 03/17/2020] [Indexed: 01/31/2023]
Abstract
For the imaging using low energy pure beta-emitting radionuclides, autoradiography is used by slicing the subjects because the range of beta particles is short and thought to be impossible to detect beta particles from outside the subjects. Contrary to this scientific consensus, we recently found that the distributions of C-14 could be measured by detecting the bremsstrahlung X-rays emitted from the solution of C-14 and may also be applicable to lower energy pure beta-emitting radionuclide, H-3. Although the detection of bremsstrahlung X-rays emitted from H-3 and C-14 may be a possible method for in-vivo imaging of small animals, the absorption of the bremsstrahlung X-rays in the subjects are significant because the energy of bremsstrahlung X-rays is relatively low. In addition, the generations of bremsstrahlung X-rays are lower for low energy beta particles. They may make the in-vivo imaging of these beta radionuclides difficult. To clarify these points for the in-vivo imaging of bremsstrahlung X-rays emitted from H-3 and C-14, we used Monte Carlo simulation to calculate the numbers of counts and the energy spectra of the bremsstrahlung X-rays emitted from H-3 and C-14 in water. The simulation results showed that the fraction of detected bremsstrahlung X-rays by a 4 cm × 4 cm detector in all emitted beta particles was 3.5 × 10-6 at 0.1 mm from the source. Thus, with a 10 M Bq of H-3, we will detect ~35 cps at 0.1 mm from the source so in-vivo imaging at surface area will be possible. For C-14, the fraction of detected bremsstrahlung X-rays by the detector without and with collimator were 7.0 × 10-5 and 1.1 × 10-6 at 10 mm from the source, respectively. Thus, with a 10 M Bq of C-14, we will detect ~700 cps and ~11 cps at 10 mm from the source without and with collimator, respectively. The count rate without collimator is easy to form an image in a short time using a low energy X-ray detector. With collimator, in-vivo imaging of distribution of C-14 will be possible. We conclude that in-vivo imaging of small animals by detecting the bremsstrahlung X-rays emitted from H-3 and C-14 is possible and promising for a new molecular imaging technology.
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Affiliation(s)
- Kouhei Nakanishi
- Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Radiology, Akita Hospital, Chiryu, Japan.
| | - Seiichi Yamamoto
- Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan.
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Yamamoto S, Nakanishi K, Furukawa T, Tomita H. Possibility analysis of bremsstrahlung x-ray imaging of C-14 radionuclide using a LaGPS radiation imaging system. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab12bd] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Han X, Turgeon R, Schulz A, Liesche J. Environmental conditions, not sugar export efficiency, limit the length of conifer leaves. TREE PHYSIOLOGY 2019; 39:312-319. [PMID: 29850887 DOI: 10.1093/treephys/tpy056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/27/2018] [Accepted: 05/17/2018] [Indexed: 06/08/2023]
Abstract
Most conifer species have needle-shaped leaves that are only a few centimeters long. In general, variation in leaf size has been associated with environmental factors, such as cold or drought stress. However, it has recently been proposed that sugar export efficiency is the limiting factor for conifer needle length, based on the results obtained using a mathematical model of phloem transport. Here, phloem transport rates in long conifer needles were experimentally determined to test if the mathematical model accurately represents phloem transport. The validity of the model's assumptions was tested by anatomical analyses and sugar quantification. Furthermore, various environmental and physiological factors were tested for their correlation with needle length. The results indicate that needle length is not limited by sugar transport efficiency, but, instead, by winter temperatures and light availability. The identification of factors that influence needle size is instrumental for using this trait as a variable in breeding programs.
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Affiliation(s)
- Xiaoyu Han
- College of Life Science, Northwest A&F University, Nongling Road 10, Yangling, China
- Biomass Energy Center for Arid Lands, Northwest A&F University, Nongling Road 10, Yangling, China
| | - Robert Turgeon
- Plant Biology Section, School of Integrative Plant Science, Cornell University, 412 Mann Library Building, Ithaca, NY, USA
| | - Alexander Schulz
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Johannes Liesche
- College of Life Science, Northwest A&F University, Nongling Road 10, Yangling, China
- Biomass Energy Center for Arid Lands, Northwest A&F University, Nongling Road 10, Yangling, China
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Vincent C, Minchin PEH, Liesche J. Noninvasive Determination of Phloem Transport Speed with Carbon-14 ( 14C). Methods Mol Biol 2019; 2014:153-162. [PMID: 31197794 DOI: 10.1007/978-1-4939-9562-2_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Studying the phloem, through which organic substances are distributed between plant organs, is challenging because of its position deep inside the plant body and its sensitivity to manipulation. The speed of phloem transport can be studied by tracers. Here a protocol for the use of 14C-labeled photoassimilate to measure phloem transport speed is provided. A major advantage of this method is its noninvasiveness, as the isotope is supplied as 14CO2, which is converted in source leaves to 14C-sugars, whose movement is then followed by photomultiplier-based X-ray detectors positioned close to the stem. The same method can be used to determine partitioning among sinks over time and rates of export from sources. The relatively simple handling enables medium throughput experiments under controlled conditions.
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Affiliation(s)
- Christopher Vincent
- Department of Horticultural Sciences, University of Florida, Lake Alfred, FL, USA
| | - Peter E H Minchin
- New Zealand Institute for Plant and Food Research, Motueka Research Centre, Motueka, New Zealand
| | - Johannes Liesche
- College of Life Sciences, Northwest A&F University, Yangling, China.
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Sugita R, Kobayashi NI, Hirose A, Tanoi K, Nakanishi TM. Evaluation of in vivo detection properties of 22Na, 65Zn, 86Rb, 109Cd and 137Cs in plant tissues using real-time radioisotope imaging system. Phys Med Biol 2014; 59:837-51. [PMID: 24487508 DOI: 10.1088/0031-9155/59/4/837] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In plant research, radioisotope imaging provides useful information about physiological activities in various tissues and elemental transport between plant organs. To expand the usage of imaging techniques, a new system was developed to visualize beta particles, x-rays and gamma-rays emitted from plant bodies. This real-time radioisotope imaging system (RRIS) visualizes radioactivity after conversion into light with a CsI(Tl) scintillator plate. Herein, the RRIS detection properties of the gamma-ray emitters (22)Na, (65)Zn, (86)Rb, (109)Cd and (137)Cs were evaluated in comparison with those of radioluminography (RLG) using an imaging plate. The lower quantitative detection limit (Bq mm(-2)) during a 15 min period ranged from 0.1 to 4, depending on the nuclide, similar to that of RLG. When the quantitative ability to detect radiation from various Arabidopsis tissues was analyzed, the quantitative capability in silique and the thick internode tended to be low. In an EGS5 simulation, beta particles were the greatest contributors to RRIS imaging of (22)Na, (86)Rb and (137)Cs, and low-energy x-rays contributed significantly to (65)Zn and (109)Cd detection. Thus, both self-absorption and air space between the sample and scintillator surface could impair quantitative RRIS imaging. Despite these issues, RRIS is suggested for quantitative time-course measurements of radionuclide motion within plants.
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Affiliation(s)
- Ryohei Sugita
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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