2024-03-28T16:11:46Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/2111642021-12-27T15:36:56Zcom_10261_15com_10261_6col_10261_268
Rosales Villegas, Miguel Á.
Maurel, Christophe
Nacry, Philippe
2020-05-12T09:59:53Z
2020-05-12T09:59:53Z
2019
Plant Physiology 180: 2198- 2211 (2019)
http://hdl.handle.net/10261/211164
10.1104/pp.18.01546
31164395
Root water uptake is influenced by root system architecture, which is determined by root growth and branching and the hydraulics of root cells and tissues. The phytohormone abscisic acid (ABA) plays a major role in the adaptation of plants to water deficit (WD). Here we addressed at the whole-root level in Arabidopsis (Arabidopsis thaliana) the regulatory role of ABA in mechanisms that determine root hydraulic architecture. Root system architecture and root hydraulic conductivity (Lpr) were analyzed in hydroponically grown plants subjected to varying degrees of WD induced by various polyethylene glycol (PEG) concentrations. The majority of root traits investigated, including first- and second-order lateral root production and elongation and whole-root hydraulics, had a bell-shaped dependency on WD, displaying stimulation under mild WD conditions (25 g PEG L-1) and repression under more severe conditions. These traits also showed a bell-shaped dependency on exogenous ABA, and their regulation by WD was attenuated in genotypes altered in ABA biosynthesis and response. Thus, we propose that ABA acts as a coordinator and an integrator of most root responses to mild and moderate WD, whereas responses to strong WD (150 g PEG L-1) are largely ABA independent. We also found that roots exhibit different growth responses to both WD and ABA depending on their rank and age. Taken together, our results give further insights into the coordinated water acquisition strategies of roots deployed in relation to WD intensity.
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Abscisic Acid Coordinates Dose-Dependent Developmental and Hydraulic Responses of Roots to Water Deficit
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