Partitioning stomatal responses to drought.

 

Most stomatal closure in woody species under moderate drought can be explained by stomatal responses to leaf turgor: Partitioning stomatal responses to drought.

by Rodriguez-Dominguez C. M.,

Buckley T. N.,

 Egea G.,

 Diaz-Espejo A.

(2016)

in Plant Cell and Environment · June 2016 – DOI: 10.1111/pce.12774

https://www.researchgate.net/publication/303782229_Most_stomatal_closure_in_woody_species_under_moderate_drought_can_be_explained_by_stomatal_responses_to_leaf_turgor_Partitioning_stomatal_responses_to_drought

Abstract

Reduced stomatal conductance (gs) during soil drought in angiosperms may result from effects of leaf turgor on stomata, and/or factors that do not directly depend on leaf turgor, including root-derived abscisic acid (ABA) signals.

To quantify the roles of leaf-turgor-mediated and leaf-turgor-independent mechanisms in gs decline during drought, we measured drought responses of gs and water relations in three woody species (almond, grapevine and olive) under a range of conditions designed to generate independent variation in leaf and root turgor, including diurnal variation in evaporative demand and changes in plant hydraulic conductance and leaf osmotic pressure.

We then applied these data to a process-based gs model and used a novel method to partition observed declines in gs during drought into contributions from each parameter in the model. Soil drought reduced gs by 63-84% across species, and the model reproduced these changes well (r2 = 0.91, p < 0.0001, n = 44) despite having only a single fitted parameter.

Our analysis concluded that responses mediated by leaf turgor could explain over 87% of the observed decline in gs across species, adding to a growing body of evidence that challenges the root-ABA-centric model of stomatal responses to drought.

Stomatal responses to leaf turgor

 

 

Most stomatal closure in woody species under moderate drought can be explained by stomatal responses to leaf turgor

by Rodriguez-Dominguez C. M.,

Buckley T. N.,

 Egea G.,

 de Cires A.,

 Hernandez-Santana V.,

 Martorell S.,

 Diaz-Espejo A.

(2016) –

in Wiley Online LIbrary: Browse Accepted Articles
Accepted, unedited articles published online and citable. The final edited and typeset version of record will appear in future.

DOI: 10.1111/pce.12774

Abstract

Reduced stomatal conductance (g_s) during soil drought in angiosperms may result from effects of leaf turgor on stomata, and/or factors that do not directly depend on leaf turgor, including root-derived abscisic acid (ABA) signals.

To quantify the roles of leaf-turgor-mediated and leaf-turgor-independent mechanisms in g_s decline during drought, we measured drought responses of g_s and water relations in three woody species (almond, grapevine and olive) under a range of conditions designed to generate independent variation in leaf and root turgor, including diurnal variation in evaporative demand and changes in plant hydraulic conductance and leaf osmotic pressure.

We then applied these data to a process-based g_s model and used a novel method to partition observed declines in g_s during drought into contributions from each parameter in the model.

Soil drought reduced g_s by 63-84% across species, and the model reproduced these changes well (r² = 0.91, p < 0.0001, n = 44) despite having only a single fitted parameter.

Our analysis concluded that responses mediated by leaf turgor could explain over 87% of the observed decline in g_s across species, adding to a growing body of evidence that challenges the root-ABA-centric model of stomatal responses to drought.