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Does night-time transpiration contribute to anisohydric behaviour in a Vitis vinifera cultivar?

Rogiers SY, Greer DH, Hutton RJ, Landsberg JJ - J. Exp. Bot. (2009)

Bottom Line: Furthermore, Psi(l) fell to significantly lower values than in any of the nine other varieties examined.Night-time values of stomatal conductance (g(n)) and transpiration (E(n)) in Semillon were up to four times higher than in other varieties; plants enclosed in plastic bags overnight to reduce E(n) resulted in better plant-soil equilibration so that predawn Psi(l) in Semillon was the same as in Grenache.The high values of g(day) were associated with high rates of transpiration (E(day)) by Semillon through a day when VPD reached 4.5 kPa.

View Article: PubMed Central - PubMed

Affiliation: National Wine and Grape Industry Centre, NSW Department of Primary Industries and Charles Sturt University, Wagga Wagga, NSW 2678, Australia. suzy.rogiers@dpi.nsw.gov.au

ABSTRACT
The hypothesis that vines of the Semillon wine grape variety show anisohydric behaviour was tested, i.e. that tissue hydration is unstable under fluctuating environmental conditions. Stomatal conductance and transpiration rates from leaves were measured during the day and at night. Leaf water potential (Psi(l)) in Semillon was negatively correlated to vapour pressure deficit (VPD) both predawn and during the day. Furthermore, Psi(l) fell to significantly lower values than in any of the nine other varieties examined. Night-time values of stomatal conductance (g(n)) and transpiration (E(n)) in Semillon were up to four times higher than in other varieties; plants enclosed in plastic bags overnight to reduce E(n) resulted in better plant-soil equilibration so that predawn Psi(l) in Semillon was the same as in Grenache. These data indicate that the hypothesis is supported, and that night-time transpiration contributes significantly to the low Psi(l) values in Semillon during warm, dry nights. The other contributing factor is daytime stomatal conductance (g(day)), which in Semillon leaves was higher than in other varieties, although the decline in g(day) with increasing VPD was greater in Semillon than in Shiraz or Grenache. The high values of g(day) were associated with high rates of transpiration (E(day)) by Semillon through a day when VPD reached 4.5 kPa. When compared to other varieties, Semillon was not unusual in terms of root length density, stomatal density, xylem sap abscisic acid, or leaf electrolyte leakage. Night-time and daytime water loss and insufficient stomatal regulation therefore account for the tendency to anisohydric behaviour shown by Semillon.

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Related in: MedlinePlus

Diurnal trend in stomatal conductance (g) and transpiration (E) of Semillon and Grenache potted vines. Soil moisture was not significantly different between varieties and averaged at 40%. Initial predawn leaf water potential (Ψleaf) of Semillon was –0.75±0.02 MPa and Grenache was –0.54±0.02 MPa.
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fig6: Diurnal trend in stomatal conductance (g) and transpiration (E) of Semillon and Grenache potted vines. Soil moisture was not significantly different between varieties and averaged at 40%. Initial predawn leaf water potential (Ψleaf) of Semillon was –0.75±0.02 MPa and Grenache was –0.54±0.02 MPa.

Mentions: Comparisons of diurnal trends in conductance and E of Semillon with Grenache under moderate soil-water-deficit conditions indicated that Grenache stomata were quicker to respond to daytime increases in PAR (Fig. 6). Early morning conductance was 1.4-fold higher for Grenache, but by mid-morning, conductance had reached a plateau. Conductance of Semillon leaves, however, continued to increase until midday and remained higher for the rest of the day and night. The large midday drop of conductance in Grenache leaves (by 50%) did not occur in Semillon. Eday did not differ between Semillon and Grenache in the morning but by mid-afternoon it was 1.8-fold greater for Semillon and remained significantly higher for the rest of the day and night. Across the whole day, Grenache vines transpired a total of 22.2 mmol m−2 while Semillon leaves transpired a total of 28.2 mmol m−2, thus 27% more water loss, in total.


Does night-time transpiration contribute to anisohydric behaviour in a Vitis vinifera cultivar?

Rogiers SY, Greer DH, Hutton RJ, Landsberg JJ - J. Exp. Bot. (2009)

Diurnal trend in stomatal conductance (g) and transpiration (E) of Semillon and Grenache potted vines. Soil moisture was not significantly different between varieties and averaged at 40%. Initial predawn leaf water potential (Ψleaf) of Semillon was –0.75±0.02 MPa and Grenache was –0.54±0.02 MPa.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2736890&req=5

fig6: Diurnal trend in stomatal conductance (g) and transpiration (E) of Semillon and Grenache potted vines. Soil moisture was not significantly different between varieties and averaged at 40%. Initial predawn leaf water potential (Ψleaf) of Semillon was –0.75±0.02 MPa and Grenache was –0.54±0.02 MPa.
Mentions: Comparisons of diurnal trends in conductance and E of Semillon with Grenache under moderate soil-water-deficit conditions indicated that Grenache stomata were quicker to respond to daytime increases in PAR (Fig. 6). Early morning conductance was 1.4-fold higher for Grenache, but by mid-morning, conductance had reached a plateau. Conductance of Semillon leaves, however, continued to increase until midday and remained higher for the rest of the day and night. The large midday drop of conductance in Grenache leaves (by 50%) did not occur in Semillon. Eday did not differ between Semillon and Grenache in the morning but by mid-afternoon it was 1.8-fold greater for Semillon and remained significantly higher for the rest of the day and night. Across the whole day, Grenache vines transpired a total of 22.2 mmol m−2 while Semillon leaves transpired a total of 28.2 mmol m−2, thus 27% more water loss, in total.

Bottom Line: Furthermore, Psi(l) fell to significantly lower values than in any of the nine other varieties examined.Night-time values of stomatal conductance (g(n)) and transpiration (E(n)) in Semillon were up to four times higher than in other varieties; plants enclosed in plastic bags overnight to reduce E(n) resulted in better plant-soil equilibration so that predawn Psi(l) in Semillon was the same as in Grenache.The high values of g(day) were associated with high rates of transpiration (E(day)) by Semillon through a day when VPD reached 4.5 kPa.

View Article: PubMed Central - PubMed

Affiliation: National Wine and Grape Industry Centre, NSW Department of Primary Industries and Charles Sturt University, Wagga Wagga, NSW 2678, Australia. suzy.rogiers@dpi.nsw.gov.au

ABSTRACT
The hypothesis that vines of the Semillon wine grape variety show anisohydric behaviour was tested, i.e. that tissue hydration is unstable under fluctuating environmental conditions. Stomatal conductance and transpiration rates from leaves were measured during the day and at night. Leaf water potential (Psi(l)) in Semillon was negatively correlated to vapour pressure deficit (VPD) both predawn and during the day. Furthermore, Psi(l) fell to significantly lower values than in any of the nine other varieties examined. Night-time values of stomatal conductance (g(n)) and transpiration (E(n)) in Semillon were up to four times higher than in other varieties; plants enclosed in plastic bags overnight to reduce E(n) resulted in better plant-soil equilibration so that predawn Psi(l) in Semillon was the same as in Grenache. These data indicate that the hypothesis is supported, and that night-time transpiration contributes significantly to the low Psi(l) values in Semillon during warm, dry nights. The other contributing factor is daytime stomatal conductance (g(day)), which in Semillon leaves was higher than in other varieties, although the decline in g(day) with increasing VPD was greater in Semillon than in Shiraz or Grenache. The high values of g(day) were associated with high rates of transpiration (E(day)) by Semillon through a day when VPD reached 4.5 kPa. When compared to other varieties, Semillon was not unusual in terms of root length density, stomatal density, xylem sap abscisic acid, or leaf electrolyte leakage. Night-time and daytime water loss and insufficient stomatal regulation therefore account for the tendency to anisohydric behaviour shown by Semillon.

Show MeSH
Related in: MedlinePlus