ArticlePlant physiology1997
Xylem Sap pH Increase: A Drought Signal Received at the Apoplastic Face of the Guard Cell That Involves the Suppression of Saturable Abscisic Acid Uptake by the Epidermal Symplast.
Article in Plant physiology, 1997. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 61 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
61 citing papers in PubMed, 373 citations in OpenAlex.
- Diurnal Changes in the Transport Rates of Ureides, Amides, Cations, Anions, and Organic Acids Estimated by Xylem Sap Exudate and the Water Flow Rate of Soybean Plants.Plants (Basel, Switzerland) · 2026Article
- Abscisic acid binds to anFrontiers in plant science · 2026Article
- Foliar Water Uptake Supports Water Potential Recovery but Does Not Affect Xylem Sap Composition in Two Salt-Secreting Mangroves.Plant, cell & environment · 2025Article
- Photosynthetic performance and sucrose metabolism in superior and inferior rice grains with overlapping growth stages under water stress.Scientific reports · 2025Article
- The fate of biodegradable polylactic acid microplastics in maize: impacts on cellular ion fluxes and plant growth.Frontiers in plant science · 2025Article
- Deposition and water repelling of temperature-responsive nanopesticides on leaves.Nature communications · 2023Article
- Seasonal variation in the xylem sap composition of six Australian trees and shrubs.AoB PLANTS · 2023Article
- A Simple Reversed Iontophoresis-Based Sensor to Enable In Vivo Multiplexed Measurement of Plant Biomarkers Using Screen-Printed Electrodes.Sensors (Basel, Switzerland) · 2023Article
- Seasonal Xylem Sap Acidification Is Governed by Tree Phenology, Temperature and Elevation of Growing Site.Plants (Basel, Switzerland) · 2022Article
- Bi-directional, long-distance hormonal signalling between roots and shoots of soil water availability.Physiologia plantarum · 2022Review
- Sustainable Biochar and/or Melatonin Improve Salinity Tolerance in Borage Plants by Modulating Osmotic Adjustment, Antioxidants, and Ion Homeostasis.Plants (Basel, Switzerland) · 2022Article
- The Tiny Companion Matters: The Important Role of Protons in Active Transports in Plants.International journal of molecular sciences · 2022Review
- Transfer of Metal(loid)s from Soil to Leaves and Trunk Xylem Sap of Medicinal Plants and Possible Health Risk Assessment.International journal of environmental research and public health · 2022Article
- Abscisic Acid: Role in Fruit Development and Ripening.Frontiers in plant science · 2022Review
- Nitrogen metabolic rate and differential ammonia volatilization regulate resistance against opportunistic fungusFrontiers in plant science · 2022Article
- ABA homeostasis and long-distance translocation are redundantly regulated by ABCG ABA importers.Science advances · 2021Article
- Plant Cell Wall Hydration and Plant Physiology: An Exploration of the Consequences of Direct Effects of Water Deficit on the Plant Cell Wall.Plants (Basel, Switzerland) · 2021Article
- Leaf apoplastic alkalization promotes transcription of the ABA-synthesizing enzyme Vp14 and stomatal closure in Zea mays.Journal of experimental botany · 2021Article
- GABA signalling modulates stomatal opening to enhance plant water use efficiency and drought resilience.Nature communications · 2021Article
- Acetic-acid-induced jasmonate signaling in root enhances drought avoidance in rice.Scientific reports · 2021Article
1 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Drought increased the pH of Commelina communis xylem sap from 6.1 to 6.7. Conductances of transpiring leaves were 50% lower in pH 7.0 than in pH 6.0 buffers, but bulk leaf abscisic acid (ABA) concentration and shoot water status were unaffected by pH. Stomatal apertures of isolated abaxial epidermis incubated on simple buffers increased with external pH, so in vivo this must be overridden by alternative pH effects. Reductions in leaf transpiration rate at pH 7.0 were dependent on the presence of 10-8 mol dm-3 ABA in the xylem stream. We inferred that at pH 7.0 leaf apoplastic ABA concentrations increased: pH did not affect distributions of ABA among leaf tissues, but isolated epidermis and mesophyll tissue took up more 3H-ABA from pH 6.0 than from pH 7.0 buffers. The apoplastic ABA increase at pH 7.0 may result from reduced symplastic sequestration. A portion of 3H-ABA uptake by the epidermis was saturable at pH 6.0 but not at pH 7.0. An ABA uptake carrier may contribute to ABA sequestration by the leaf symplast of well-watered plants, and its inactivity at pH 7.0 may favor apoplastic ABA accumulation in draughted plants. Effects of external pH on stomatal apertures in the isolated epidermis indicate that published data supporting a role for internal guard cell ABA receptors should be reassessed.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.