Effects of water deficit stress on the developmental growth of excised tomato roots cultured in vitro

• Published in: In vitro cellular & developmental biology. Plant 1997-07, Vol.33 (3), p.245-251
• Main Authors: Hooker, T.S. (University of Calgary, Calgary, Canada.), Thorpe, T.A
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; BIOLOGICAL DEVELOPMENT; CULTIVO DE TEJIDOS; CULTURE DE TISSU; CULTURE MEDIA; Dehydration; DESARROLLO BIOLOGICO; Developmental biology; DEVELOPPEMENT BIOLOGIQUE; Drought; DROUGHT STRESS; Ecological deficits; ESTRES DE SEQUIA; Fundamental and applied biological sciences. Psychology; LATERAL ROOTS; LYCOPERSICON ESCULENTUM; MANITOL; MANNITOL; MEDIO DE CULTIVO; MILIEU DE CULTURE; OSMOREGULACION; OSMOREGULATION; OSMOTIC PRESSURE; OSMOTIC STRESS; Physical agents; Physiology; Plant physiology and development; Plant roots; Plants; POTENTIEL HYDRIQUE; PRESION OSMOTICA; PRESSION OSMOTIQUE; RACINE; RAICES; Root growth; ROOT PRIMORDIA; Root tips; ROOTS; SACCHAROSE; Soil water; Soil water deficit; STRESS DU A LA SECHERESSE; SUCROSA; SUCROSE; TENSION DE ABSORCION; TISSUE CULTURE; TURGENCIA; TURGESCENCE; TURGOR; Vegetative apparatus, growth and morphogenesis. Senescence; WATER POTENTIAL; WATER STRESS
• ISSN: 1054-5476; 1475-2689
• DOI: 10.1007/s11627-997-0031-9

Excised tomato roots (Lycopersicon esculentum Mill, cv Bonny Best) were cultured in the presence of mannitol to determine the effects of varying degrees of mild water deficit on their developmental growth. It was found that over the 7-d culture period, the cultured roots could regulate their own developmental responses to the water deficit such that elongation of the primary root axis was favored over that of the lateral roots. Higher degrees of water deficit proportionately decreased lateral root number and density, but lateral root primordia (visualized by clearing roots in chromium trioxide) continued to be formed in water-stressed roots. Measurements of water and osmotic (solute) potentials of the root tips showed that the cultured roots osmoregulated and did not suffer a loss in turgor pressure as a result of the mannitol treatments. However, reciprocal transfer experiments showed that root cultures were unable to resume growth after removal from water deficit conditions, thus indicating a probable requirement for the shoot for complete recovery.