Cycloheximide inhibits root water flow and stomatal conductance in aspen (<i>Populus tremuloides</i>) seedlings

Voicu, Mihaela C.; Zwiazek, Janusz J.

doi:10.1111/j.1365-3040.2003.01135.x

Cited by 32 publications

(26 citation statements)

References 51 publications

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“…That changes in root L 0 are likely to be among the initial signals triggering stomatal closure and reducing transpiration rates in response to soil stress factors (Wan and Zwiazek, 1999;Voicu and Zwiazek, 2004) is consistent with our observed reductions of G s and E by salinity (Figs. 2a and 2b).…”

Section: Discussionsupporting

confidence: 80%

The effects of the combination of salinity and excess boron on the water relations of tolerant tomato (Solanum lycopersicum L.) cv. Poncho Negro, in relation to aquaporin functionality

Contreras¹,

Montoya²,

Pacheco³

et al. 2011

Span. j. agric. res.

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As elevated levels of boron (B) are accompanied by conditions of excessive salinity with drastic consequences for crops, it is crucial to find a crop that is tolerant to these conditions. In this work, the interaction between salinity and excess B with respect to aquaporin-mediated changes by blockade of mercury and water relations were studied as well as the osmotic adjustment of the plants. The treatments, for tomato 'Poncho Negro' cultivated hydroponically in a controlled environment chamber, were control (75 and 150 mM) NaCl and/or 5 mg L -1 or 20 mg L -1 B. Hydraulic conductance (L 0 ) of detached exuding root systems exhibits large variations in response to abiotic stimuli. No additive (synergic) effects of B and salinity were observed. Under salinity, the plants increased their turgor, compensating for the decrease in the leaf water potential through the reduction in the leaf osmotic potential by the accumulation of soluble sugars and proline. The involvement of Hg 2+ -insensitive aquaporins or the osmotic gradient as the main force for water flow through the apoplastic pathway must be contemplated. Finally, all the data reveal the tomato cv. Poncho Negro to be a germplasm of agronomic interest and a good alternative for cultivation areas with high content of salts and the excess B of the soil and irrigation water.Additional key words: boric acid; plant water relations; root hydraulic conductance; tomato Poncho Negro. ResumenEfectos de la combinación de salinidad y exceso de boro en las relaciones hídricas del tomate (Solanum lycopersicum L.) tolerante cv. Poncho Negro y su relación con la funcionalidad de las acuaporinas En muchas ocasiones niveles elevados de boro (B) van acompañados de condiciones de excesiva salinidad, cuyas consecuencias pueden ser drásticas para los cultivos, por lo que es fundamental encontrar variedades que puedan tolerar estas condiciones. En este trabajo, se estudió cómo la interacción entre la salinidad y el exceso de B afecta a la actividad de las acuaporinas y a las relaciones hídricas, así como al ajuste osmótico de las plantas. Se cultivó en hidroponía tomate cv Poncho Negro en una cámara de crecimiento con ambiente controlado con los tratamientos control, NaCl (75 y 150 mM) y/o B (5 ó 20 mg L -1 ). No se observó ningún efecto aditivo (sinergia) del exceso de B y la salinidad. Las plantas aumentaron su turgencia en condiciones salinas, compensando así la disminución del potencial hídrico foliar, a través de la reducción de su potencial osmótico por la acumulación de azúcares solubles y prolina. La participación de acuaporinas insensibles al Hg +2 o del gradiente osmótico, como la principal fuerza impulsora del flujo del agua, a través de la vía apoplástica, deben ser contemplados. Finalmente, todos los datos revelan que el tomate cv. Poncho Negro puede ser un germoplasma de interés agronómico y una buena alternativa para cultivar en condiciones de alto contenido de sales y exceso de B del suelo y del agua de riego.Palabras clave adicionales: acido bórico; conductanc...

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Section: Discussionsupporting

confidence: 80%

The effects of the combination of salinity and excess boron on the water relations of tolerant tomato (Solanum lycopersicum L.) cv. Poncho Negro, in relation to aquaporin functionality

Contreras¹,

Montoya²,

Pacheco³

et al. 2011

Span. j. agric. res.

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“…7B and 8A). Similar short effects of CHX on hydraulic conductivity have been reported in rain tree (Samanea saman) motor cells (Moshelion et al, 2002) and in aspen seedling roots (Voicu and Zwiazek, 2004) and are indicative of the importance of the protein-mediated water transport through these organs.…”

Section: Two Distinct Water Pathways In Walnut Leavessupporting

confidence: 75%

“…A similar finding was reported in oak (Quersus robur) leaves (Cochard et al, 2000), where a dramatic and irreversible K leaf increase was observed for temperatures above 35°C. Because CHX has already been reported to inhibit the osmotic water permeability in some plant species (Moshelion et al, 2002;Voicu and Zwiazek, 2004), we also investigated the effect of short CHX treatment (within 1 h) on the conductance of this dark water pathway. Like temperature, 0.1 mM CHX perfusion was found to have no significant effect on the dark conductance (Fig.…”

Section: Two Distinct Water Pathways In Walnut Leavesmentioning

confidence: 99%

Putative Role of Aquaporins in Variable Hydraulic Conductance of Leaves in Response to Light

et al. 2006

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Molecular and physiological studies in walnut (Juglans regia) are combined to establish the putative role of leaf plasma membrane aquaporins in the response of leaf hydraulic conductance (K leaf ) to irradiance. The effects of light and temperature on K leaf are described. Under dark conditions, K leaf was low, but increased by 400% upon exposure to light. In contrast to dark conditions, K leaf values of light-exposed leaves responded to temperature and 0.1 mM cycloheximide treatments. Furthermore, K leaf was not related to stomatal aperture. Data of real-time reverse transcription-polymerase chain reaction showed that K leaf dynamics were tightly correlated with the transcript abundance of two walnut aquaporins (JrPIP2,1 and JrPIP2,2). Low K leaf in the dark was associated with down-regulation, whereas high K leaf in the light was associated with up-regulation of JrPIP2. Light responses of K leaf and aquaporin transcripts were reversible and inhibited by cycloheximide, indicating the importance of de novo protein biosynthesis in this process. Our results indicate that walnut leaves can rapidly change their hydraulic conductance and suggest that these changes can be explained by regulation of plasma membrane aquaporins. Model simulation suggests that variable leaf hydraulic conductance in walnut might enhance leaf gas exchanges while buffering leaf water status in response to ambient light fluctuations.

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“…To determine root hydraulic conductivity (L pr , s −1 MPa −1 ), root volumes were measured for each root system using the water volume displacement method (Voicu and Zwiazek 2004). Following the volume measurements, approximately 15 root tips were excised from inoculated (MYCO) and noninoculated (CTRL) plants for microscopic examination of root colonization (Siemens and Zwiazek 2008).…”

Section: Ph Treatmentsmentioning

confidence: 99%

Hebeloma crustuliniforme modifies root hydraulic responses of trembling aspen (Populus tremuloides) seedlings to changes in external pH

Siemens

Zwiazek

2011

Plant Soil

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The main objective of the study was to compare the effects of short-duration pH treatments on root hydraulic properties in trembling aspen (Populus tremuloides) seedlings that were either inoculated with the ectomycorrhizal fungus Hebeloma crustuliniforme or remained non-inoculated (control). Inoculated and non-inoculated plants were exposed in solution culture to the root zone pH ranging from 4 to 9 and their root hydraulic conductivity was examined using the hydrostatic method and after subjecting the plants to treatments with 100 μM HgCl 2 (aquaporin blocker) and 0.02% trisodium 3-hydroxy-5,8,10-pyrenetrisulfonic acid (apoplastic transport tracer). In a separate experiment, pure cultures of H. crustuliniforme were also grown on a slid medium with the pH ranging from 4 to 9 to determine their pH growth optimum and changes in medium pH over time in the presence and absence of 8 mM NH 4 NO 3 . When grown in pure culture, H. crustuliniforme demonstrated maximum growth at pH 7-8 and was capable of modifying the pH of its growth media, especially in the presence of NH 4 NO 3 . The plants that were inoculated with H. crustuliniforme had a maximum root hydraulic conductivity at pH 7. At this pH, root hydraulic conductivity was significantly higher compared with non-inoculated plants and showed greater sensitivity of root water transport to pH changes relative to non-inoculated seedlings. Relative apoplastic flux was largely unaffected by pH in inoculated seedlings. Fungal inoculation modified the response of root hydraulic conductivity to pH. The increased root hydraulic conductivity in inoculated seedlings was likely due to an increase in aquaporinmediated cell-to-cell water transport, particularly at the higher pH. A possible role of fungal aquaporins in the root hydraulic conductivity responses of mycorrhizzal plants should be examined.

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Cycloheximide inhibits root water flow and stomatal conductance in aspen (Populus tremuloides) seedlings

Cited by 32 publications

References 51 publications

The effects of the combination of salinity and excess boron on the water relations of tolerant tomato (Solanum lycopersicum L.) cv. Poncho Negro, in relation to aquaporin functionality

The effects of the combination of salinity and excess boron on the water relations of tolerant tomato (Solanum lycopersicum L.) cv. Poncho Negro, in relation to aquaporin functionality

Putative Role of Aquaporins in Variable Hydraulic Conductance of Leaves in Response to Light

Hebeloma crustuliniforme modifies root hydraulic responses of trembling aspen (Populus tremuloides) seedlings to changes in external pH

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