Recovery estimates and prognostic factors for oculomotor nerve palsy.

The root system is the principal interface between plants and the soil environment, securing anchorage and acquiring water and mineral nutrients []. Within the soil–plant–atmosphere continuum (SPAC), water movement is driven by a water potential gradient across successive hydraulic resistances, flowing from the bulk soil to the stomatal cavity [,]. Although traditionally viewed as a passive segment of this continuum, an expanding body of evidence has repositioned the root system as the primary integrator of plant water status regulation and the dominant control point for stomatal closure under progressive soil drying []. Whereas the classical leaf-centric paradigm attributed stomatal closure to declines in leaf water potential and xylem hydraulic conductance [,], subsequent studies have demonstrated that closure frequently precedes xylem failure thresholds, implicating the soil–root interface as the earliest bottleneck constraining transpiration [,,]. Reference [] formalized this by proposing that conductance loss at the soil–root interface, rather than xylem vulnerability, is the primary trigger of stomatal regulation under drought conditions. This framework has gained empirical traction across functionally diverse species, including olive [], tomato [], wheat [], and grapevine [], and has been consolidated as a unifying principle of crop hydraulic behavior in water-limited environments [], repositioning the root as the primary regulator of stomatal aperture during soil drying rather than a passive conduit. The mechanism by which roots exert hydraulic control under drought conditions relies on complementary processes operating in parallel. On the one hand, root hydraulic conductivity is dynamically tuned through aquaporin gating and abundance at the plasma membrane [,]. In contrast, the radial pathway of water transport is concurrently reshaped by plastic remodeling of the endodermis, particularly through the deposition of apoplastic barriers, such as suberin lamellae and Casparian strips, which constrain apoplastic flow []. Collectively, these adjustments modulate water uptake but impose a substantial biosynthetic and energetic cost [] that can only be met by a concomitant reconfiguration of the primary root metabolism []. Among these metabolic responses, the accumulation of compatible osmolytes (including soluble carbohydrate pools and low-molecular-weight nitrogenous solutes) is widely recognized as the primary driver of osmotic adjustment, lowering the tissue osmotic potential to sustain water uptake and turgor as the soil water potential declines [,]. Among these, soluble sugars, such as glucose, fructose, and sucrose, are dynamically modulated under water deficit, acting in a dual capacity: as compatible solutes that lower the cellular osmotic potential and sustain turgor-driven water uptake, and as respiratory substrates that provide the energy required to maintain active membrane transport under carbon-limiting conditions [,,]. Beyond these osmotic and bioenergetic roles, a fraction of these sugars is redirected to play an additional protective role against oxidative damage during drought [,,]. Similar to soluble sugars, nitrogen-rich solutes (such as GABA and amino acids) and tricarboxylic acid (TCA) cycle intermediates function beyond basic osmotic adjustment; under stress, they act in a comparable manner to regulate cytosolic pH, maintain redox homeostasis, and sustain cellular energy status [,]. Taken together, these metabolic adjustments provide the osmotic, protective, and energetic currency that underpins the hydraulic and anatomical remodeling of the root outlined above [], thereby positioning root primary metabolism as a central determinant of water-uptake capacity during both drought and recovery. Despite these advances, the temporal coordination of these three components (hydraulic, structural, and metabolic) within the root system and whether such coordination is preserved after post-drought recovery remains largely unresolved. Among the halophytic crops of high agronomic value, quinoa ( Willd.) has emerged as a valuable model for stress resilience owing to its exceptional combination of drought and salinity tolerance, agronomic plasticity, and nutritional value [,,,]. Quinoa is a facultative halophyte of the Amaranthaceae whose prolonged domestication across the Andes, from the altiplano to sea level, has generated five recognized ecotypes (highland, inter-Andean valley, salares, Yungas, and coastal lowlands) and a correspondingly broad intraspecific variability []. Chilean germplasm is genetically and ecophysiologically among the most diverse within this range [,], and tolerance to drought and salinity is strongly genotype-dependent, generally tracking the aridity of the habitat of origin [,,]. However, drought research on quinoa has focused primarily on shoot-level descriptors (such as leaf gas exchange, photosynthetic performance, and leaf water relations), leaving root systems sign