Dissecting the rootstock control of scion transpiration using model-assisted analyses in grapevine.

How rootstocks contribute to the control of scion transpiration under drought is poorly understood. We investigated the role of root characteristics, hydraulic conductance and chemical signals (abscisic acid, ABA) in the response of stomatal conductance (gs) and transpiration (E) to drought in Cabernet Sauvignon (Vitis vinifera) grafted onto drought-sensitive (Vitis riparia) and drought-tolerant (Vitis berlandieri × Vitis rupestris 110R) rootstocks. All combinations showed a concomitant reduction in gs and E, and an increase in xylem sap ABA concentration during the drought cycle.

Expression of ABA synthesis and metabolism genes under different irrigation strategies and atmospheric VPDs is associated with stomatal conductance in grapevine (Vitis vinifera L. cv Cabernet Sauvignon).

The influence of different levels of irrigation and of variation in atmospheric vapour pressure deficit (VPD) on the synthesis, metabolism, and transport of abscisic acid (ABA) and the effects on stomatal conductance were examined in field-grown Cabernet Sauvignon grapevines. Xylem sap, leaf tissue, and root tissue were collected at regular intervals during two seasons in conjunction with measurements of leaf water potential (Ψleaf) and stomatal conductance (gs). The different irrigation levels significantly altered the Ψleaf and gs of the vines across both seasons.

Thermal infrared imaging of crop canopies for the remote diagnosis and quantification of plant responses to water stress in the field.

Thermal imaging using infrared (IR) is now an established technology for the study of stomatal responses and for phenotyping plants for differences in stomatal behaviour. This paper outlines the potential applications of IR sensing in drought phenotyping, with particular emphasis on a description of the problems with extrapolation of the technique from the study of single leaves in controlled environments to the study of plant canopies is field plots, with examples taken from studies on grapevine (Vitis vinifera L.) and rice (Oryza sativa L.

Influence of plant water status on the production of C13-norisoprenoid precursors in Vitis vinifera L. Cv. cabernet sauvignon grape berries.

The influence of irrigation strategy on grape berry carotenoids and C13-norisoprenoid precursors was investigated for Vitis vinifera L. cv. Cabernet Sauvignon.

Gradients in stomatal conductance, xylem sap ABA and bulk leaf ABA along canes of Vitis vinifera cv. Shiraz: molecular and physiological studies investigating their source.

Gradients were observed in xylem sap ABA and in stomatal conductance along canes of Vitis vinifera L. cv. Shiraz.

Stomatal control by chemical signalling and the exploitation of this mechanism to increase water use efficiency in agriculture.

Stomatal behaviour of plants in drying soil can be regulated by (long distance) chemical signals that provide the shoot with some measure of water availability. Although much emphasis has been placed on the plant hormone abscisic acid (ABA) as a central component of the signalling process, soil drying will modify the delivery to the shoot of a range of potential chemical signals. Here we consider the role that changes in the xylem sap pH might play in determining the access that ABA has to sites of action on the guard cells.