TY - JOUR
T1 - Root-to-shoot ABA signaling does not contribute to genotypic variation in stomatal functioning induced by high relative air humidity
AU - Carvalho, Dália R. A.
AU - Fanourakis, Dimitrios
AU - Correia, Maria J.
AU - Monteiro, José A.
AU - Araújo-Alves, José Pedro L.
AU - Vasconcelos, Marta W.
AU - Almeida, Domingos P. F.
AU - Heuvelink, Ep
AU - Carvalho, Susana M. P.
N1 - Funding Information:
The authors thank the Foundation for Science and Technology (Portugal) for financial support by the PhD grant SFRH/BD/72924/2010 to Dália R.A. Carvalho and by the project GreenRose — PTDC/AGR-AAM/67082/2006 . Thanks also to Hugo Botelho and Ana Monteiro for their help in conducting part of the measurements.
Publisher Copyright:
© 2015 Elsevier B.V.
Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - High relative air humidity (RH ≥85%) during leaf expansion hampers stomatal responsiveness to closing stimuli, a genotype-dependent effect. Genotypes with reduced stomatal closure in response to closing stimuli (i.e., sensitive genotypes) show low bulk leaf abscisic acid concentration ([ABA]). We hypothesized that the amount of ABA produced in the roots and delivered with the transpiration stream to the leaves is a critical step for a proper stomatal functioning in high RH-grown plants. Ten genotypes from a cut rose tetraploid population were grown at moderate (62%) or high (89%) RH. Stomatal anatomy and responsiveness to desiccation or ABA feeding were evaluated. Root and leaf petiole xylem sap [ABA] were quantified, and ABA delivery rate from root-to-shoot was estimated. High RH reduced stomatal responsiveness to both closing stimuli in the sensitive genotypes, whereas it had a non-significant effect in the tolerant ones. Estimates of [ABA] in root xylem sap at transpirational flow rate were not related to the genotypic differences in the sensitivity to high RH. However, high RH increased this concentration irrespective of the genotype, probably due to a reduced dilution of the [ABA] in the xylem sap as a result of a lower transpiration rate compared to moderate RH-grown plants. Leaf petiole xylem sap [ABA] was neither related to the genotypic differences in the sensitivity to high RH nor it was affected by RH. We concluded that genotypic differences in the stomatal sensitivity to high RH cannot be explained by changes in the [ABA] delivered with the transpiration stream from the roots to the leaves.
AB - High relative air humidity (RH ≥85%) during leaf expansion hampers stomatal responsiveness to closing stimuli, a genotype-dependent effect. Genotypes with reduced stomatal closure in response to closing stimuli (i.e., sensitive genotypes) show low bulk leaf abscisic acid concentration ([ABA]). We hypothesized that the amount of ABA produced in the roots and delivered with the transpiration stream to the leaves is a critical step for a proper stomatal functioning in high RH-grown plants. Ten genotypes from a cut rose tetraploid population were grown at moderate (62%) or high (89%) RH. Stomatal anatomy and responsiveness to desiccation or ABA feeding were evaluated. Root and leaf petiole xylem sap [ABA] were quantified, and ABA delivery rate from root-to-shoot was estimated. High RH reduced stomatal responsiveness to both closing stimuli in the sensitive genotypes, whereas it had a non-significant effect in the tolerant ones. Estimates of [ABA] in root xylem sap at transpirational flow rate were not related to the genotypic differences in the sensitivity to high RH. However, high RH increased this concentration irrespective of the genotype, probably due to a reduced dilution of the [ABA] in the xylem sap as a result of a lower transpiration rate compared to moderate RH-grown plants. Leaf petiole xylem sap [ABA] was neither related to the genotypic differences in the sensitivity to high RH nor it was affected by RH. We concluded that genotypic differences in the stomatal sensitivity to high RH cannot be explained by changes in the [ABA] delivered with the transpiration stream from the roots to the leaves.
KW - Abscisic acid
KW - Relative water content
KW - Rosa×hybrida
KW - Stomatal anatomy
KW - Vapor pressure deficit
KW - Water loss
UR - http://www.scopus.com/inward/record.url?scp=84946926381&partnerID=8YFLogxK
U2 - 10.1016/j.envexpbot.2015.11.001
DO - 10.1016/j.envexpbot.2015.11.001
M3 - Article
AN - SCOPUS:84946926381
SN - 0098-8472
VL - 123
SP - 13
EP - 21
JO - Environmental and Experimental Botany
JF - Environmental and Experimental Botany
ER -