Abstract
A quantitative light and electron microscope study of developing and degenerating mycorrhizal arbuscules of Glomus fasciculatum in Zea mays was carried out in order to estimate three parameters during the colonization cycle. These were: 1) Vv(f,c), the fraction of the host cell volume occupied by a volume of fungus; 2) Vv(cy,c), the fraction of the host cell volume occupied by host cytoplasm; 3) Sv(pr,c), the surface-area-to-volume ratio of the host protoplast to the whole host cell. Uninfected cortical cells had an Sv(pr,c) of 0.13 μm2/μm3. As the fungus penetrates the cell wall, the protoplast invaginates, causing a decrease in protoplast volume and an increase in protoplast Sv. The Sv(pr,c) of a cell containing a mature arbuscule is 1.275 μm2/μm3. Because of the shrinkage of the protoplast, the Sv of the protoplast to its own volume rather than the original cell volume is 2.55 μm2/μm3, or almost a 20-fold increase. Total cell size is unaffected. When the arbuscule is mature, the fungus occupies 42% of the cell, with 24% as 1-μm-diam branches, and 18% as trunk. Arbuscular branch formation progresses at a linear rate and is the most important factor in causing the increased host Sv. The correlation coefficient for Vv(br,c) the volume fraction for arbuscular branches, vs. Sv(pr,c) is r = 0.932 (P < 0.001). Degeneration of the arbuscule is marked by a rapid decrease in branches, host Sv, and host cytoplasm. The trunk develops and degenerates at a slower rate than the branches.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 14
Claim · model-written summary
Uninfected cortical cells of Zea mays had a protoplast surface-to-cell-volume ratio Sv(pr,c) of 0.13 μm2/μm3.
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“Uninfected cortical cells had an Sv(pr,c) of 0.13 μm2/μm3”
Claim · model-written summary
As the fungus penetrates the cell wall, the protoplast invaginates and protoplast volume decreases.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“As the fungus penetrates the cell wall, the protoplast invaginates, causing a decrease in protoplast volume and an increase in protoplast Sv”
Claim · model-written summary
As the fungus penetrates the cell wall, protoplast Sv increases.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“As the fungus penetrates the cell wall, the protoplast invaginates, causing a decrease in protoplast volume and an increase in protoplast Sv”
Claim · model-written summary
The Sv(pr,c) of a cell containing a mature arbuscule is 1.275 μm2/μm3.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“The Sv(pr,c) of a cell containing a mature arbuscule is 1.275 μm2/μm3”
Claim · model-written summary
The Sv of the protoplast relative to its own volume is 2.55 μm2/μm3, almost a 20-fold increase.
- Outcome
- Sv of the protoplast to its own volumee0
- Value
- 2.55 μm2/μm3e0
- Qualifier
- almost a 20-fold increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“the Sv of the protoplast to its own volume rather than the original cell volume is 2.55 μm2/μm3, or almost a 20-fold increase”
Claim · model-written summary
Total cell size is unaffected.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“Total cell size is unaffected”
Claim · model-written summary
When the arbuscule is mature, the fungus occupies 42% of the host cell.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“When the arbuscule is mature, the fungus occupies 42% of the cell”
Claim · model-written summary
In the mature arbuscule, 24% of the cell is occupied by 1-μm-diam branches.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“with 24% as 1-μm-diam branches”
Claim · model-written summary
In the mature arbuscule, 18% of the cell is occupied by trunk.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“and 18% as trunk”
Claim · model-written summary
Arbuscular branch formation progresses at a linear rate.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“Arbuscular branch formation progresses at a linear rate and is the most important factor in causing the increased host Sv”
Claim · model-written summary
Arbuscular branch formation is the most important factor causing the increased host Sv.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“Arbuscular branch formation progresses at a linear rate and is the most important factor in causing the increased host Sv”
Claim · model-written summary
The volume fraction of arbuscular branches Vv(br,c) correlated with Sv(pr,c) at r = 0.932.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“The correlation coefficient for Vv(br,c) the volume fraction for arbuscular branches, vs. Sv(pr,c) is r = 0.932 (P < 0.001)”
Claim · model-written summary
Degeneration of the arbuscule is marked by a rapid decrease in branches, host Sv and host cytoplasm.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“Degeneration of the arbuscule is marked by a rapid decrease in branches, host Sv, and host cytoplasm”
Claim · model-written summary
The trunk develops and degenerates at a slower rate than the branches.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Zea Mays”
e0“The trunk develops and degenerates at a slower rate than the branches”