Physiological and biochemical responses of tomato microshoots to induced salinity stress with associated ethylene accumulation

Abstract

Physiological and biochemical responses of open-pollinated 'Roma' and dwarf F1 hybrid 'Patio' tomato (Lycopersicon esculentum Mill.) cultivars to in vitro induced salinity were examined in light of the possible contribution of ethylene to these symptoms. Salinity was induced by incorporating 0 (control), 50, 100, 150, or 200 mM NaCl into shoot culture media. Elevated salinity treatments significantly enhanced ethylene accumulation in the headspace and were accompanied by increased leaf epinasty in both cultivars. Growth, leaf cell sap osmolarity, leaf tissue viability and shoot soluble protein content were generally depressed with elevated salinity treatments, whereas electrolyte leakage, membrane injury, raffinose, and total sugars were concomitantly increased. Macronutrients N, P, K, Ca, Mg, and S decreased with elevated salinity in both cultivars and were accompanied by a significant increase in Na content and a sharp decrease in K/Na ratio. Tissue micronutrients, Fe, B, Zn, Mn, and Cu were generally decreased with elevated salinity especially at 100 mM or more. Incorporating ethylene inhibitors CoCl 2 or NiCl 2 at 5.0 or 10.0 mg/l into media supplemented with 100 mM NaCl significantly reduced ethylene accumulation in the headspace and prevented epinasty, but did not eliminate the negative impacts on growth and other physiological parameters caused by salinity treatment in either cultivar. Our results indicate that the increase in ethylene under salinity stress is not the primary factor contributing to salinity's deleterious effect on tomato plant growth and physiology.

Effects of NaCl on growth, ion accumulation, protein, proline contents and antioxidant enzymes activity in callus cultures of Jatropha curcas

“…The decrease in Ca accumulation observed in our study may be due to displacement of Ca from cell membrane by Na (Cramer et al 1985;Shibli et al 2007). Decreased Mg accumulation under saline condition is in agreement with earlier results (Shibli et al 2007). The decrease in protein content observed at the higher NaCl concentration (100 mM) in nutrient medium may be due to decrease in the synthesis of protein (Hall & Flowers 1973) or stimulation of protein hydrolysis (Uprety & Sarin 1976) whereas, the increase in protein content at 20, 40, 60 and 80 mM may be attributed to stress induced synthesis of proteins (Cherian & Reddy 2003).…”

“…Potassium takes part in many enzymatic activities in plant cell and maintaining cystosolic Na/K ratio is a key requirement for growth under high saline conditions (Apse et al 1999). The decrease in Ca accumulation observed in our study may be due to displacement of Ca from cell membrane by Na (Cramer et al 1985;Shibli et al 2007). Decreased Mg accumulation under saline condition is in agreement with earlier results (Shibli et al 2007).…”

“…In the present study it was observed that NaCl provoked an inhibition of cell growth, which may be due to nutritional imbalance, osmotic and metabolic disturbances. Elkahoui et al (2005) in Catharanthus roseus, Cherian & Reddy (2003) in Suaeda nudiflora, Niknam et al (2006) in Trigonella species, and Shibli et al (2007) in Lycopersicon species observed similar results. Na accumulation in tissues under salinity stress is generally considered as a major factor behind the adverse effect of salinity on nutrient uptake and growth (Shibli et al 2001).…”

Effect of various soil salinity level on the antioxidant and physiological properties of corn plant (Zea mays)

“…Salinity stress is one of the most important environmental factors which is responsible for the reducing plant productions (Nakano & Asada, 1980). This may be due to the effect of this high salinity on the physiology, growth and development of plants (Orcutt &Nilsen , 2000;Bandeoğlu et al, 2004;ElTayeb,2005;Shibli et al, 2007). Dry weight of plants by increasing the salinity degree of soil shows a descending trend and this is due to the impaired absorption of nutrients required for plant growth.…”

Antioxidative defense mechanism of the ruderal Verbascum olympicum Boiss. against copper (Cu)-induced stress

“…Seeds were collected from 1850-1900 m elevation of Uludağ Mountain, Turkey and were stored in paper The cell membrane permeability (%): (EC 1 /EC 2 )*100 Also, cell membrane injury was expressed according to the formula above expressed as a percentage, [18]:…”