scholarly journals An Argon-Ion-Induced Pale Green Mutant of Arabidopsis Exhibiting Rapid Disassembly of Mesophyll Chloroplast Grana

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 848
Author(s):  
Alvin Sanjaya ◽  
Yusuke Kazama ◽  
Kotaro Ishii ◽  
Ryohsuke Muramatsu ◽  
Kengo Kanamaru ◽  
...  

Argon-ion beam is an effective mutagen capable of inducing a variety of mutation types. In this study, an argon ion-induced pale green mutant of Arabidopsis thaliana was isolated and characterized. The mutant, designated Ar50-33-pg1, exhibited moderate defects of growth and greening and exhibited rapid chlorosis in photosynthetic tissues. Fluorescence microscopy confirmed that mesophyll chloroplasts underwent substantial shrinkage during the chlorotic process. Genetic and whole-genome resequencing analyses revealed that Ar50-33-pg1 contained a large 940 kb deletion in chromosome V that encompassed more than 100 annotated genes, including 41 protein-coding genes such as TYRAAt1/TyrA1, EGY1, and MBD12. One of the deleted genes, EGY1, for a thylakoid membrane-localized metalloprotease, was the major contributory gene responsible for the pale mutant phenotype. Both an egy1 mutant and F1 progeny of an Ar50-33-pg1 × egy1 cross-exhibited chlorotic phenotypes similar to those of Ar50-33-pg1. Furthermore, ultrastructural analysis of mesophyll cells revealed that Ar50-33-pg1 and egy1 initially developed wild type-like chloroplasts, but these were rapidly disassembled, resulting in thylakoid disorganization and fragmentation, as well as plastoglobule accumulation, as terminal phenotypes. Together, these data support the utility of heavy-ion mutagenesis for plant genetic analysis and highlight the importance of EGY1 in the structural maintenance of grana in mesophyll chloroplasts.

2021 ◽  
Vol 22 (8) ◽  
Author(s):  
Andi Muliarni Okasa ◽  
Rinaldi Sjahril ◽  
Muhammad Riadi ◽  
Meta Mahendradatta ◽  
Tadashi Sato ◽  
...  

Abstract. Okasa AM, Sjahril R, Riadi M, Mahendradatta M, Sato T, Toriyama K, Ishii K, Hayashi Y, Abe T. 2021. Evaluation of Toraja (Indonesia) local aromatic rice mutant developed using heavy-ion beam irradiation. Biodiversitas 22: 3474-3481. The aromatic local Toraja rice "Pare Bau" has a good grain quality and aroma. However, it has some disadvantages, including a late heading and low yield for a modern farming system. This study aims to evaluate and select early heading as well as high yield mutant lines induced by heavy-ion beam irradiation. Furthermore, dry seeds of Pare Bau were irradiated with Argon-ion (300 keV/?m) and Carbon-ion (30 keV/?m) at RI-beam factory, RIKEN Nishina Center, Japan. The germination percentages of the M1 seeds were 49% for Pare Bau irradiated with Argon-ion (PB-A), 53% for Pare Bau irradiated with Carbon-ion (PB-C), and 70% for the Control. The 13 PB-A and 13 PB-C M1 plants were selected, and the seeds were sampled in the paddy field of Hasanuddin University (20 m asl.), Makassar. During the following planting season, the M2 generation plant was examined in Enrekang District (650 m asl.), South Sulawesi, Indonesia. Based on the early heading and a larger number of panicles, the 18 PB-A and one PB-C M3 line were selected from a total of 404 M2 survival plants. The selected lines and control were grouped into seven clusters based on the quantitative phenotypic traits, indicating the existence of genetic variability. The plant yield was significantly correlated with plant height, the number of tillers, the number of panicles, as well as grain weight per panicle, which showed that these traits are good criteria for selection.


2016 ◽  
Vol 57 (3) ◽  
pp. 318-324 ◽  
Author(s):  
Takuya Maeyama ◽  
Nobuhisa Fukunishi ◽  
Kenichi L. Ishikawa ◽  
Kazuaki Fukasaku ◽  
Shigekazu Fukuda

Abstract The radiological properties of nanocomposite Fricke gel (NC-FG) dosimeters prepared with different concentrations of nano-clay, perchloric acid and ferrous ions in deaerated conditions were investigated under carbon and argon ion beam irradiation covering a linear-energy-transfer (LET) range of 10 to 3000 eV/nm. We found that NC-FG exhibits radiological properties distinct from those of conventional Fricke gel. The radiation sensitivity of NC-FG is independent of the LET and is nearly constant even at very high LET (3000 eV/nm) values in the Bragg peak region of the argon ion beam. In addition, whereas conventional Fricke gel dosimeters only operate under acidic conditions, NC-FG dosimeters function under both acidic and neutral conditions. The radiation sensitivity decreases with decreasing nano-clay concentration in NC-FG, which indicates that the nano-clay plays a vital role in the radiation-induced oxidation of Fe 2+ .


1991 ◽  
Vol 341 (1) ◽  
pp. 111-115 ◽  
Author(s):  
A. Ulrich ◽  
J. Wieser ◽  
R. Pfaffenberger ◽  
B. Busch ◽  
W. Kr�tz ◽  
...  

1989 ◽  
Vol 94 (A3) ◽  
pp. 2645 ◽  
Author(s):  
R. E. Erlandson ◽  
L. J. Cahill ◽  
R. L. Kaufmann ◽  
C. J. Pollock ◽  
R. L. Arnoldy
Keyword(s):  
Ion Beam ◽  

Author(s):  
M. Spector ◽  
A. C. Brown

Ion beam etching and freeze fracture techniques were utilized in conjunction with scanning electron microscopy to study the ultrastructure of normal and diseased human hair. Topographical differences in the cuticular scale of normal and diseased hair were demonstrated in previous scanning electron microscope studies. In the present study, ion beam etching and freeze fracture techniques were utilized to reveal subsurface ultrastructural features of the cuticle and cortex.Samples of normal and diseased hair including monilethrix, pili torti, pili annulati, and hidrotic ectodermal dysplasia were cut from areas near the base of the hair. In preparation for ion beam etching, untreated hairs were mounted on conducting tape on a conducting silicon substrate. The hairs were ion beam etched by an 18 ky argon ion beam (5μA ion current) from an ETEC ion beam etching device. The ion beam was oriented perpendicular to the substrate. The specimen remained stationary in the beam for exposures of 6 to 8 minutes.


Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.


Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.


2018 ◽  
Author(s):  
C.S. Bonifacio ◽  
P. Nowakowski ◽  
M.J. Campin ◽  
M.L. Ray ◽  
P.E. Fischione

Abstract Transmission electron microscopy (TEM) specimens are typically prepared using the focused ion beam (FIB) due to its site specificity, and fast and accurate thinning capabilities. However, TEM and high-resolution TEM (HRTEM) analysis may be limited due to the resulting FIB-induced artifacts. This work identifies FIB artifacts and presents the use of argon ion milling for the removal of FIB-induced damage for reproducible TEM specimen preparation of current and future fin field effect transistor (FinFET) technologies. Subsequently, high-quality and electron-transparent TEM specimens of less than 20 nm are obtained.


1995 ◽  
Author(s):  
A. Fujisawa ◽  
A. Ouroua ◽  
J.W. Heard ◽  
T.P. Crowley ◽  
P.M. Schoch ◽  
...  

1997 ◽  
Vol 4 (5) ◽  
pp. 1357-1361 ◽  
Author(s):  
A. Fujisawa ◽  
H. Iguchi ◽  
S. Lee ◽  
T. P. Crowley ◽  
Y. Hamada ◽  
...  

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