Physiological and biochemical responses resulting from nitrite accumulation in tomato (Lycopersicon esculentum Mill. cv. Ibiza F1).
The sensitivity of hydroponically cultivated tomato (Lycopersicon esculentum Mill. cv. Ibiza F1) submitted to nitrite treatments (0.25-10mM KNO(2)) for 7d was studied. Increasing nitrite levels in the culture medium led to several disruptions of tomato plants, reflected by reductions of both dry matter per plant, chlorophyll concentrations and the appearance of chlorosis symptoms at the leaf surface. This behaviour was accompanied by stimulation of nitrite, nitrate and ammonia ion accumulation, mainly in roots and old leaves. Higher proteolytic and gaiacol peroxidase (GPX, EC. 1.11.1.7) activities and malonyldialdehyde content were also noted. Protein content of the different plant organs was decreased by nitrite treatment. These physiological and biochemical parameters were chosen as they are stress indicators. Taken together, our data partly explain the harmful effects of nitrite ions, when excessive in the culture medium.
Ezzine
Monia
M
Unité de Recherche Nutrition et Métabolisme Azotés et Protéines de Stress UR 99/ C09-20, Département des Sciences Biologiques, Faculté des Sciences de Tunis, Campus Universitaire, 1060 Tunis El Manar, Tunisia. moniaz_tn@yahoo.fr <moniaz_tn@yahoo.fr>
Ghorbel
Mohamed Habib
MH
D018527:Hydroponics; D015227:Lipid Peroxidation; D018551:Solanum lycopersicum / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D008315:Malondialdehyde / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism* / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000254:growth & development; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development
D009573:Nitrites; D008315:Malondialdehyde