TY  - EJOU
AU  - Dávila, José G. Joya 
AU  - Miceli, Federico A. Gutiérrez 
AU  - Gómez, Leslie A. Serrano 
AU  - Camacho, Olivia Tzintzun 
AU  - Hernández, Dagoberto Durán 
AU  - Navarro, Alexis Salazar 
AU  - Cervantes-García, David 
AU  - Cortes, Ulin Antobelli Basilio 
AU  - Gutiérrez, Anayancy Lam 
AU  - Mendoza, Daniel González 

TI  - Progressive Water Deficit Modulates Growth, Photosynthetic Pigments, and Proline Accumulation in <i>Theobroma cacao</i> L. Seedlings
T2  - Phyton-International Journal of Experimental Botany

PY  - 
VL  - 
IS  - 
SN  - 1851-5657

AB  - Water deficit is one of the major constraints to the establishment and early growth of cacao (<i>Theobroma cacao</i> L.), particularly under increasingly frequent and intense drought conditions. The objective of this study was to evaluate the morphological and physiological responses of cacao seedlings subjected to progressive water deficit under nursery conditions. Plants were evaluated over a 45-day period without irrigation and compared with well-watered plants maintained at 60% of substrate field capacity. Growth variables, photosynthetic pigment concentrations, and proline accumulation in leaves, stems, and roots were evaluated. Stem length showed no significant differences between treatments, whereas root length and fresh biomass decreased as the water deficit was prolonged. Dry biomass remained unchanged under moderate stress but was significantly reduced when the irrigation-free period was extended, indicating that stress duration was the primary factor influencing plant growth. Water-stressed seedlings maintained higher chlorophyll concentrations throughout the experimental period, whereas proline accumulation increased, reaching a maximum after 30 days of water deficit, with increases of approximately 119%, 71%, and 147% in leaves, stems, and roots, respectively, before declining under prolonged stress. Stress duration was identified as the main factor determining the magnitude of the physiological responses, revealing a distinct temporal- and organ-dependent pattern of proline accumulation. Overall, these findings demonstrate that the morphological and biochemical responses of cacao seedlings to water deficit occur in a coordinated manner and are primarily determined by stress duration, providing new insights into the temporal dynamics of proline accumulation and associated physiological responses during the early developmental stages of cacao.
KW  - Osmotic adjustment; abiotic stress; drought; tropical perennial species

DO  - 10.32604/phyton.2026.087160