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A rapid dehydration leaf assay reveals stomatal response differences in grapevine genotypes.

Hopper DW, Ghan R, Cramer GR - Hortic Res (2014)

Bottom Line: Shiraz, V. vinifera cv.Grenache and V. vinifera cv.Differences in stomatal response to ABA were also detected.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Nevada , Reno, NV 89557, USA.

ABSTRACT
A simple and reliable way of phenotyping plant responses to dehydration was developed. Fully-developed leaves were detached and placed in a closed plastic box containing a salt solution to control the atmospheric water potential in the container. Three hours of dehydration (weight loss of the leaf) was optimal for measuring changes in stomatal response to dehydration. Application of the plant hormone abscisic acid (ABA) prior to leaf detachment decreased the amount of water loss, indicating that the assay was able to detect differences based on a stomatal response to dehydration. Five different Vitis genotypes (V. riparia, V. champinii, V. vinifera cv. Shiraz, V. vinifera cv. Grenache and V. vinifera cv. Cabernet Sauvignon) with known differences in drought tolerance were screened for their dehydration response and the results obtained corresponded to previous reports of stomatal responses in the vineyard. Significant differences in stomatal density along with differences in the amount and rate of water lost indicate differences in dehydration sensitivity among the genotypes screened. Differences in stomatal response to ABA were also detected. Shiraz had the lowest stomatal density and the highest ABA sensitivity among the genotypes screened, yet Shiraz lost the most amount of water, indicating that it was the least sensitive to dehydration. Despite having the highest stomatal density and intermediate stomatal sensitivity to ABA, V. riparia lost the smallest amount of water, indicating that it was the most sensitive to dehydration. The assay presented here represents a simple and reliable phenotyping method for plant responses to leaf dehydration.

No MeSH data available.


Related in: MedlinePlus

Water loss of Cabernet Sauvignon leaves over an 8-h period. Intermediate leaves were selected based on their position from the shoot tip (fifth to sixth leaf). Water loss for the first hour and a half follows a linear trend followed by a decrease in the amount of water lost. Each data point is presented as the mean±s.e.m. (n=4). The dotted line was fitted to the first three time points by linear regression.
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fig1: Water loss of Cabernet Sauvignon leaves over an 8-h period. Intermediate leaves were selected based on their position from the shoot tip (fifth to sixth leaf). Water loss for the first hour and a half follows a linear trend followed by a decrease in the amount of water lost. Each data point is presented as the mean±s.e.m. (n=4). The dotted line was fitted to the first three time points by linear regression.

Mentions: A good screen for phenotyping plants should use methods that are relatively simple and fast. A leaf dehydration assay was developed with this intent. Leaves were excised and placed into a plastic box containing a salt solution. The leaves were weighed over time to measure the amount of water loss (see the section on ‘Materials and methods’). In an initial test of the system, Cabernet Sauvignon leaves were treated for 8 h of dehydration (Figure 1). The response was multiphasic with a near linear relationship in the beginning of water loss with time. A linear regression was plotted for the first hour and a half and had an r2 of 0.91 and a slope of 0.0012 (dotted line in Figure 1). Subsequently, water loss diminished with a decay-like function over the course of 3 h, eventually reaching another linear phase for the rest of the 8 h. It was determined that the first 3-h time window was optimal for detecting changes in water loss from the leaf and this time window was used for all further experiments. A major assumption is that water loss is occurring primarily through the stomata and that they are responding by closing during the dehydration event. Other sources of water loss through the cuticle or cut end of the petiole were considered to be negligible.


A rapid dehydration leaf assay reveals stomatal response differences in grapevine genotypes.

Hopper DW, Ghan R, Cramer GR - Hortic Res (2014)

Water loss of Cabernet Sauvignon leaves over an 8-h period. Intermediate leaves were selected based on their position from the shoot tip (fifth to sixth leaf). Water loss for the first hour and a half follows a linear trend followed by a decrease in the amount of water lost. Each data point is presented as the mean±s.e.m. (n=4). The dotted line was fitted to the first three time points by linear regression.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591676&req=5

fig1: Water loss of Cabernet Sauvignon leaves over an 8-h period. Intermediate leaves were selected based on their position from the shoot tip (fifth to sixth leaf). Water loss for the first hour and a half follows a linear trend followed by a decrease in the amount of water lost. Each data point is presented as the mean±s.e.m. (n=4). The dotted line was fitted to the first three time points by linear regression.
Mentions: A good screen for phenotyping plants should use methods that are relatively simple and fast. A leaf dehydration assay was developed with this intent. Leaves were excised and placed into a plastic box containing a salt solution. The leaves were weighed over time to measure the amount of water loss (see the section on ‘Materials and methods’). In an initial test of the system, Cabernet Sauvignon leaves were treated for 8 h of dehydration (Figure 1). The response was multiphasic with a near linear relationship in the beginning of water loss with time. A linear regression was plotted for the first hour and a half and had an r2 of 0.91 and a slope of 0.0012 (dotted line in Figure 1). Subsequently, water loss diminished with a decay-like function over the course of 3 h, eventually reaching another linear phase for the rest of the 8 h. It was determined that the first 3-h time window was optimal for detecting changes in water loss from the leaf and this time window was used for all further experiments. A major assumption is that water loss is occurring primarily through the stomata and that they are responding by closing during the dehydration event. Other sources of water loss through the cuticle or cut end of the petiole were considered to be negligible.

Bottom Line: Shiraz, V. vinifera cv.Grenache and V. vinifera cv.Differences in stomatal response to ABA were also detected.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, University of Nevada , Reno, NV 89557, USA.

ABSTRACT
A simple and reliable way of phenotyping plant responses to dehydration was developed. Fully-developed leaves were detached and placed in a closed plastic box containing a salt solution to control the atmospheric water potential in the container. Three hours of dehydration (weight loss of the leaf) was optimal for measuring changes in stomatal response to dehydration. Application of the plant hormone abscisic acid (ABA) prior to leaf detachment decreased the amount of water loss, indicating that the assay was able to detect differences based on a stomatal response to dehydration. Five different Vitis genotypes (V. riparia, V. champinii, V. vinifera cv. Shiraz, V. vinifera cv. Grenache and V. vinifera cv. Cabernet Sauvignon) with known differences in drought tolerance were screened for their dehydration response and the results obtained corresponded to previous reports of stomatal responses in the vineyard. Significant differences in stomatal density along with differences in the amount and rate of water lost indicate differences in dehydration sensitivity among the genotypes screened. Differences in stomatal response to ABA were also detected. Shiraz had the lowest stomatal density and the highest ABA sensitivity among the genotypes screened, yet Shiraz lost the most amount of water, indicating that it was the least sensitive to dehydration. Despite having the highest stomatal density and intermediate stomatal sensitivity to ABA, V. riparia lost the smallest amount of water, indicating that it was the most sensitive to dehydration. The assay presented here represents a simple and reliable phenotyping method for plant responses to leaf dehydration.

No MeSH data available.


Related in: MedlinePlus