scholarly journals A novel cucumber albino mutant caused by chloroplast development deficiency

2020 ◽  
Author(s):  
Jinqiang Yan ◽  
Bin Liu ◽  
Zhenqiang Cao ◽  
Piaoyun Sun ◽  
Wenrui Liu ◽  
...  
Keyword(s):  
Chloroplast Development ◽  
Light Condition ◽  
Chlorophyll Synthesis ◽  
Higher Plant ◽  
Chlorophyll Metabolism ◽  
Real Time Quantitative Pcr ◽  
Transmission Electron ◽  
Albino Mutant ◽  
New Material ◽  
Recessive Mutant

Abstract Background Photosynthesis is a fundamental process for plant growth and development dependent on a precise network, including formation of chloroplast and chlorophyll synthesis. Chloroplast development deficiency could lead to albinism in higher plant. Results Here, we report a cucumber albino recessive mutant that processed white cotyledons under light condition and is unable to produce first true leaf. Meanwhile, albino mutant could grow out creamy green cotyledons under dark condition but died after exposing to light. Using fluorescence microscopy and transmission electron microscope (TEM), impaired chloroplasts were observed. We identified 7 and 3 differentially expressed genes (DEG) involved in Chlorophyll metabolism and Methylerythritol 4-phosphate (MEP) pathway through transcriptome analysis, respectively. We also examined the reported homologous genes for albino mutants from other plants. Two of 12 genes, TOC159 and DXS1, were up-regulated in cucumber albino mutants as well. The reliability of RNA sequencing results were further confirmed by real-time quantitative PCR (qPCR). Conclusions Taken together, we elaborate the differences between albino mutant and normal seedlings from a single cucumber progeny. This mutant is a new material to study protoplast development.

Measurement of ferrochelatase activity using a novel assay suggests that plastids are the major site of haem biosynthesis in both photosynthetic and non-photosynthetic cells of pea (Pisum sativum L.)

2002 ◽  
Vol 362 (2) ◽  
pp. 423-432 ◽  
Author(s):  
Johanna E. CORNAH ◽  
Jennifer M. ROPER ◽  
Davinder Pal SINGH ◽  
Alison G. SMITH
Keyword(s):  
Ferrous Iron ◽  
Specific Activity ◽  
Higher Plants ◽  
Protoporphyrin Ix ◽  
Chlorophyll Synthesis ◽  
Marker Enzyme ◽  
Hexane Extraction ◽  
Higher Plant ◽  
Major Site ◽  
Haem Biosynthesis

Ferrochelatase is the terminal enzyme of haem biosynthesis, catalysing the insertion of ferrous iron into the macrocycle of protoporphyrin IX, the last common intermediate of haem and chlorophyll synthesis. Its activity has been reported in both plastids and mitochondria of higher plants, but the relative amounts of the enzyme in the two organelles are unknown. Ferrochelatase is difficult to assay since ferrous iron requires strict anaerobic conditions to prevent oxidation, and in photosynthetic tissues chlorophyll interferes with the quantification of the product. Accordingly, we developed a sensitive fluorimetric assay for ferrochelatase that employs Co2+ and deuteroporphyrin in place of the natural substrates, and measures the decrease in deuteroporphyrin fluorescence. A hexane-extraction step to remove chlorophyll is included for green tissue. The assay is linear over a range of chloroplast protein concentrations, with an average specific activity of 0.68nmol·min−1·mg of protein−1, the highest yet reported. The corresponding value for mitochondria is 0.19nmol·min−1·mg of protein−1. The enzyme is inhibited by N-methylprotoporphyrin, with an estimated IC50 value of ≈ 1nM. Using this assay we have quantified ferrochelatase activity in plastids and mitochondria from green pea leaves, etiolated pea leaves and pea roots to determine the relative amounts in the two organelles. We found that, in all three tissues, greater than 90% of the activity was associated with plastids, but ferrochelatase was reproducibly detected in mitochondria, at levels greater than the contaminating plastid marker enzyme, and was latent. Our results indicate that plastids are the major site of haem biosynthesis in higher plant cells, but that mitochondria also have the capacity for haem production.

Sporophytes, megaspores, and massulae of Azolla stanleyi from the Paleocene Joffre Bridge locality, Alberta

1994 ◽  
Vol 72 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Georgia L. Hoffman ◽  
Ruth A. Stockey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Key Words ◽  
Red Deer ◽  
The Other ◽  
Evolutionary Trends ◽  
Reproductive Structures ◽  
Transmission Electron ◽  
New Material

Several hundred vegetative and fertile specimens of Azolla Lam. have been recovered from the Paleocene Paskapoo Formation at the Joffre Bridge locality (Middle Tiffanian (Ti3) age) near Red Deer, Alberta. The spore complexes closely resemble those of the Paleocene A. stanleyi Jain & Hall, and the vegetative material is referred to that species. The specimens are unusually complete in that the remains of the fragile sporophyte are preserved, commonly with reproductive structures in place. Plants reaching up to 2.25 cm in length consist of alternately branched rhizomes bearing alternate, imbricate, sessile leaves. Leaves are ovate with entire margins, papillate surfaces, and a single midvein. Reproductive structures have been examined using light, scanning, and transmission electron microscopy. This new material is compared with the other Paleocene species for which sporophytes are known and discussed in terms of evolutionary trends for the genus. The specimens suggest that most of the vegetative characteristics of modern Azolla species were established by the middle Paleocene. Key words: Azolla, Salviniaceae, megaspore, massula, ultrastructure, Paleocene.

Chloroplast Development: Fine Structure and Chlorophyll Synthesis

1972 ◽  
Vol 47 (2) ◽  
pp. 160-191 ◽  
Author(s):  
Joanne Rosinski ◽  
Walter G. Rosen
Keyword(s):  
Fine Structure ◽  
Chloroplast Development ◽  
Chlorophyll Synthesis

Advanced Computing in Electron Microscopy, Earl J. Kirkland 1998. Plenum Press, New York and London. 260 pages. ($72.50)

1999 ◽  
Vol 5 (5) ◽  
pp. 371-372
Author(s):  
John Spence
Keyword(s):  
Electron Microscopy ◽  
New York ◽  
Recent Observation ◽  
High Resolution Electron Microscopy ◽  
Atomic Level ◽  
Phase Identification ◽  
Transmission Electron ◽  
Resolution Electron ◽  
New Material ◽  
Advanced Computing

The recent observation of Bucky-tubes by S. Iijima using a transmission electron microscope (TEM) represents the first occasion in which a useful new material, subsequently available in commercial quantities, has been discovered by high-resolution electron microscopy (HREM). More commonly, the HREM method has been used for microcharacterization of materials at the atomic level, and for phase identification of submicrometer-sized microphases and polytypes.

Notizen: Changes in the Iron and Phosphorus Content of Stroma Inclusions during Etioplast-Chloroplast Development in Nicotiana

1977 ◽  
Vol 32 (1-2) ◽  
pp. 139-142
Author(s):  
B. Jülich ◽  
G. Gliem ◽  
A. G. S Jánossy
Keyword(s):  
Conformational Changes ◽  
Phosphorus Content ◽  
Chloroplast Development ◽  
Prolamellar Body ◽  
High Electron ◽  
Formation Processes ◽  
Thin Sections ◽  
X Ray ◽  
Transmission Electron ◽  
Phosphorus Containing

Conformational changes of the thylakoid arrangement during light-dependent etioplast-chloroplast development in cotyledons of Nicotiana clevelandii X N. glutinosa are correlated with a decrease of the iron and phosphorus content in electron-dense stroma inclusions. Parallel to the transformation of the prolamellar body and the stacking process of the thylakoids, both the iron and phosphorus content of the inclusions were found to be reduced. Their elemental composition was analysed by means of the energy-dispersive X-ray microanalysis. Due to their high electron-density these stroma inclusions can be observed by conventional transmission electron microscopy in unstained thin-sections from exclusively glutaraldehyde-fixed material. They seem to be involved in membrane formation processes concomitant with the dispersal of the prolamellar bodies. Thus, the iron and phosphorus containing inclusions were found either closely surrounded by membranes or in the intralamellar space of plastids from plantlets illuminated for 1 - 8 hours. In chloroplasts (illumination period 12 -24 hours) no connections between these inclusions and the thylakoids were noticed.

The ultrastructure of the cuticle and sheath of infective juveniles of entomopathogenic steinernematid nematodes

1998 ◽  
Vol 72 (3) ◽  
pp. 257-266 ◽  
Author(s):  
M.N. Patel ◽  
D.J. Wright
Keyword(s):  
Electron Microscopy ◽  
Steinernema Carpocapsae ◽  
The Other ◽  
Fluid Content ◽  
Transmission Electron ◽  
New Material ◽  
Per Se ◽  
Cuticle Thickness ◽  
Substantial Change ◽  
Median Layer

AbstractThe ultrastructure of the cuticle of infective juveniles (IJs) of Steinernema carpocapsae (newly emerged and 80-day-old) and newly emerged IJs of S. riobravis, S. feltiae and S. glaseri was examined using transmission electron microscopy. The thickness of four distinctive layers of the cuticle was measured: epicuticle, cortical and median layer, striated layer and fibrous mat. The thickness of the cuticle was correlated with the size of the IJ. In the case of newly emerged IJs, the smallest species, S. carpocapsae, had a cuticle thickness of c. 270 nm compared with c. 460 nm for S. glaseri, the largest of the four species. The overall thickness of the cuticle or the thickness of the cuticle layers was not correlated with the ability of the IJs of the four species to survive desiccation per se. The major difference between newly emerged IJs of the four species was that S. carpocapsae had a proportionately thicker striated layer compared with the other three species. The significance of this is not known but it may be an adaptation involving the nictation behaviour of this species. A substantial change was observed in the cuticle of aged (80-day-old) IJs of S. carpocapsae, whereby the thickness of the cortical and median layer increased by more than 100% and the overall thickness of the cuticle increased by about 50%. Two possible explanations for this increase are: (i) new material was synthesized; or (ii) the fluid content of this layer increased due to an increase in the permeability of the outer layers of the cuticle. The ultrastructure of the sheaths of S. feltiae and S. glaseri was also examined and, apart from S. glaseri having a thicker sheath, the structure of the sheath in both species was similar, with the epicuticle and striated layer still visible.

Laccase Biosensor Based on Ag-Doped TiO2 Nanoparticles on CuCNFs for the Determination of Hydroquinone

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650132 ◽  
Author(s):  
Jie Yang ◽  
Dawei Li ◽  
Zengyuan Pang ◽  
Qufu Wei
Keyword(s):  
Electron Microscopy ◽  
Storage Stability ◽  
Electrochemical Impedance ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
New Material ◽  
And Storage

A novel nanomaterial composed of copper and carbon nanofibers (CuCNFs) decorated with Ag-doped TiO2 (Ag–TiO[Formula: see text] nanoparticles was prepared through electrospinning, carbonization and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The obtained composites were mixed with laccase and Nafion to construct novel hydroquinone biosensor. The electrochemical behavior of the novel biosensor was studied using cyclic voltammetry (CV) and chronoamperometry. The results demonstrated that the biosensor possessed a wide detection linear range (1.20–176.50[Formula: see text][Formula: see text]M), a good selectivity, repeatability, reproducibility and storage stability. This work provides a new material to design more efficient laccase (Lac) based biosensor for hydroquinone detection.

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