Abstract
Auxin is one of the crucial regulators of plant growth and development. The discovered auxin cytosolic receptor (TIR1) is not involved in the perception of the hormone signal at the plasma membrane. Instead, another receptor, related to the ABP1, auxin binding protein1, is supposed to be responsible for the perception at the plasma membrane. One of the fast and sensitive auxin-induced reactions is an increase of Ca(2+) cytosolic concentration, which is suggested to be dependent on the activation of Ca(2+) influx through the plasma membrane. This investigation was carried out with a plasmalemma enriched vesicle fraction, obtained from etiolated maize coleoptiles. The magnitude of Ca(2+) efflux through the membrane vesicles was estimated according to the shift of potential dependent fluorescent dye diS-C₃-(5). The obtained results showed that during coleoptiles ageing (3rd, 4th and 5th days of seedling etiolated growth) the magnitude of Ca(2+) efflux from inside-out vesicles was decreased. Addition of ABP1 led to a recovery of Ca(2+) efflux to the level of the youngest and most sensitive cells. Moreover, the efflux was more sensitive, responding from 10(-8) to 10(-6) M 1-NAA, in vesicles containing ABP1, whereas native vesicles showed the highest efflux at 10(-6) M 1-NAA. We suggest that auxin increases plasma membrane permeability to Ca(2+) and that ABP1 is involved in modulation of this reaction.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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 6
Claim · model-written summary
Ca2+ efflux from vesicles decreased as coleoptiles aged over days 3 to 5 of etiolated growth.
- Treatment
- coleoptiles ageing (3rd, 4th and 5th days of seedling etiolated growth)e2
- Outcome
- magnitude of Ca(2+) effluxe2
- Direction
- decreasede2
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“obtained from etiolated maize coleoptiles”
e2“during coleoptiles ageing (3rd, 4th and 5th days of seedling etiolated growth) the magnitude of Ca(2+) efflux from inside-out vesicles was decreased”
Claim · model-written summary
Adding ABP1 restored Ca2+ efflux to the level of the youngest and most sensitive cells.
- Treatment
- Addition of ABP1e3
- Outcome
- Ca(2+) effluxe3
- Direction
- recoverye3
- Comparator
- the youngest and most sensitive cellse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“obtained from etiolated maize coleoptiles”
e3“Addition of ABP1 led to a recovery of Ca(2+) efflux to the level of the youngest and most sensitive cells”
Claim · model-written summary
ABP1-containing vesicles responded to 1-NAA from 10(-8) to 10(-6) M with a more sensitive efflux than native vesicles.
- Material
- vesicles containing ABP1e4
- Treatment
- 1-NAAe4
- Gene
- ABP1e4
- Outcome
- effluxe4
- Direction
- more sensitivee4
- Value
- 10(-8) to 10(-6) Me4
- Comparator
- native vesiclese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“obtained from etiolated maize coleoptiles”
e4“the efflux was more sensitive, responding from 10(-8) to 10(-6) M 1-NAA, in vesicles containing ABP1”
e5“whereas native vesicles showed the highest efflux at 10(-6) M 1-NAA”
Claim · model-written summary
Native vesicles showed their highest Ca2+ efflux at 10(-6) M 1-NAA.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“obtained from etiolated maize coleoptiles”
e5“whereas native vesicles showed the highest efflux at 10(-6) M 1-NAA”
Claim · model-written summary
Auxin is suggested to increase plasma membrane permeability to Ca2+.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“obtained from etiolated maize coleoptiles”
e6“We suggest that auxin increases plasma membrane permeability to Ca(2+)”
Claim · model-written summary
ABP1 is suggested to be involved in modulating the auxin-induced Ca2+ reaction.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“obtained from etiolated maize coleoptiles”
e7“ABP1 is involved in modulation of this reaction”