Abstract
Raffinose family oligosaccharides (RFO) accumulate in many developing seeds and are degraded during seed germination. However, acidic α-galactosidase (AGAL) activity and subcellular location do not correlate with raffinose depletion; alkaline α-galactosidases (AGA) may be responsible for RFO hydrolysis in germinating seeds. Three cDNA clones for AGA / SEED IMBIBITION PROTEIN were obtained from the Pioneer Hi-Bred maize expressed sequence database. Two of the clones were expressed in Escherichia coli , and the recombinant proteins, when incubated with naturally occurring galactosides or p -nitrophenyl α-d-galactose, exhibited AGA activity with maximum catalysis at pH 7.5 (ZmAGA1) or pH 8.5 (ZmAGA3). No raffinose biosynthetic capacity was observed with either enzyme. Maximal α-galactosidase activity in mature dehydrated, germinating and germinated maize ( Zea mays ) seeds occurred at pH 7.5. ZmAGA1 was the sole family member detected in seeds and maize Hi-II, embryo-derived, callus cells. Its transcript accumulated when seed germination was interrupted by heat, cold or dehydration stress, but not in response to NaCl. Tissue prints localized transcripts to the scutellum or the embryo axis, depending on the stress applied. In maize Hi-II callus cells, transcripts accumulated when callus was subjected to heat stress (42 °C), during which ZmAGA1 transcript accumulation was further induced by sucrose. Galactosides in a variety of forms, including raffinose, partially repressed the sucrose-induced accumulation of transcript in heat-stressed callus.
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 12
Claim · model-written summary
Three AGA/seed imbibition protein cDNA clones were obtained from a maize expression database.
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Three cDNA clones for AGA / SEED IMBIBITION PROTEIN were obtained from the Pioneer Hi-Bred maize expressed sequence database.”
Claim · model-written summary
Recombinant ZmAGA1 had maximum catalysis at pH 7.5.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“exhibited AGA activity with maximum catalysis at pH 7.5 (ZmAGA1)”
t0“maize”
Claim · model-written summary
Recombinant ZmAGA3 had maximum catalysis at pH 8.5.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“exhibited AGA activity with maximum catalysis at pH 7.5 (ZmAGA1) or pH 8.5 (ZmAGA3)”
t0“maize”
Claim · model-written summary
Neither tested enzyme showed raffinose biosynthetic capacity.
- Outcome
- No raffinose biosynthetic capacitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“No raffinose biosynthetic capacity was observed with either enzyme.”
t0“maize”
Claim · model-written summary
Maize seed alpha-galactosidase activity peaked at pH 7.5.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Maximal α-galactosidase activity in mature dehydrated, germinating and germinated maize ( Zea mays ) seeds occurred at pH 7.5.”
Claim · model-written summary
ZmAGA1 was the only family member detected in seeds and embryo-derived callus.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ZmAGA1 was the sole family member detected in seeds and maize Hi-II, embryo-derived, callus cells.”
Claim · model-written summary
ZmAGA1 transcript accumulated when germination was interrupted by heat, cold or dehydration.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Its transcript accumulated when seed germination was interrupted by heat, cold or dehydration stress, but not in response to NaCl.”
t0“maize”
e1“ZmAGA1 was the sole family member detected in seeds”
Claim · model-written summary
ZmAGA1 transcript did not accumulate under NaCl stress.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Its transcript accumulated when seed germination was interrupted by heat, cold or dehydration stress, but not in response to NaCl.”
t0“maize”
e1“ZmAGA1 was the sole family member detected in seeds”
Claim · model-written summary
Transcript location depended on stress, occurring in scutellum or embryo axis.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Tissue prints localized transcripts to the scutellum or the embryo axis, depending on the stress applied.”
t0“maize”
Claim · model-written summary
Heat stress caused ZmAGA1 transcript accumulation in Hi-II callus.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In maize Hi-II callus cells, transcripts accumulated when callus was subjected to heat stress (42 °C)”
e1“ZmAGA1 was the sole family member detected in seeds”
Claim · model-written summary
Sucrose further induced transcript accumulation in heat-stressed callus.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ZmAGA1 transcript accumulation was further induced by sucrose.”
t0“maize”
Claim · model-written summary
Galactosides including raffinose partially repressed sucrose-induced transcript accumulation.
- Treatment
- Galactosides in a variety of forms, including raffinosee0
- Outcome
- accumulation of transcripte0
- Direction
- partially repressede0
- Comparator
- sucrose-inducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Galactosides in a variety of forms, including raffinose, partially repressed the sucrose-induced accumulation of transcript in heat-stressed callus.”
t0“maize”
The same questions in other papers
sucrose · molecular: expression · Zea mays (maize)Positive and negative results
5 papers in the same direction as this paper · 2 in the opposite direction
- negative
- no effect
- positive
4 papers more in this group
See all 8 papers →sodium chloride · molecular: expression · Zea mays (maize)Positive and negative results
2 papers in the same direction as this paper · 7 reporting no difference from an alternative
- positive
- positive
- positive
6 papers more in this group
See all 10 papers →heat · molecular: expression · Zea mays (maize)Positive and negative results
9 papers in the same direction as this paper · 10 in the opposite direction
- no effect
- negative
- no effect
16 papers more in this group
See all 20 papers →cold · molecular: expression · Zea mays (maize)Positive and negative results
20 papers in the same direction as this paper · 10 in the opposite direction · 1 reporting no difference from an alternative
- negative
- no effect
- no effect
28 papers more in this group
See all 32 papers →drought · molecular: expression · Zea mays (maize)Positive and negative results
42 papers in the same direction as this paper · 22 in the opposite direction
- no effect
- negative
- no effect
61 papers more in this group
See all 65 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.