Growth responses of NaCl stressed rice (Oryza sativa L.) plants germinated from seed in aseptic nutrient cultures supplemented with proline

Negative impact of salinity on plant germination is significant because of abundance of Na+ in culture medium, which causes growth inhibition. Effect of salinity (NaCl) in the presence of proline was assessed in rice (Oryza sativa L.) variety Khushbo-95 at seedling stage. Seeds were cultured on MS0 (MS basal medium), MS1 (MS0 + 100 mM NaCl) and MS2 (MS1 + 5 mM proline) for 20 days. Seedlings and its biomass decreased in saline culture. Similarly, total protein and sugar contents also decreased, while reducing sugars and proline contents increased. These parameters were observed to be slightly adverse in cultures supplemented with proline (MS2) and NaCl (MS2). Among cultures, leaf demography (cell size) was affected significantly; this may be the reflection of accumulation of proline, Na+ and Cl- and exclusion of K+ in developed rice seedlings.Key words: Oryza sativa L., seedling biomass, epidermal cells, proline content

Characteristics of micro-propagated banana (Musa spp.) cultures stressed with NaCl and polyethylene glycol

The effect of NaCl and PEG was assessed on plant micro-propagation rate in banana (Musa spp.) cv., Basrai. Well micro-propagated plantlets were cultured on four different stresses of NaCl and PEG-4000 including control level: MS2b (MS0 + 3.0 mg l-1 BAP), MS2c (MS0 + 100 mol m-3 NaCl), MS2d (MS0 + 5% PEG) and MS2e (MS0 + 100 mol m-3 NaCl + 5 % PEG) for 6-weeks. Efficiency of plant micro-propagation was reduced significantly among the stressed cultures. Similarly, photosynthetic pigments like chl a was decreased non-significantly but chl b, chl ab were decreased significantly. Total carotenoids were increased in the saline as well as PEG stressed cultures. Cell size of epidermis and aerenchyma was increased (p < 0.05), while parenchyma decreased. Proline and glycinebetain contents were increased (p < 0.05) in each stressed culture but were high in MS2 than in MS3 and MS4 cultures. Meanwhile, proteins, sugars, phenolics and nitrates were observed to be in the reversed (p < 0.05) phenomena. In conclusion, NaCl treatment was observed to be most toxic than the PEG or PEG with NaCl on the banana micro-propagation.Key words: Musa spp., micro-propagation, NaCl (sodium chloride), PEG (polyethylene glycol), chlorophyll contents, proline, reducing sugars

Programming of obesity and cardiovascular disease.

BACKGROUND: There is evidence that malnutrition in early life induces a growth retardation leading, in adult life, to manifest components of the metabolic syndrome. However, the impact on obesity seems less clearly established. OBJECTIVE: To review the effects of foetal and postnatal malnutrition on the programming of obesity in the context of the metabolic syndrome, as well as the link between central obesity and cardiovascular diseases. METHODS: Included in the review were recent papers exploring the mechanisms linking maternal nutrition with impaired foetal growth and later obesity, cardiovascular disease, hypertension and diabetes in humans and animals. RESULTS: The programming of obesity during foetal and early postnatal life depends of the timing of maternal malnutrition as well as the postnatal environment. Obesity arises principally in offspring submitted to malnutrition during early stages of gestation and which presented early catch-up growth. The programming may involve the dysregulation of appetite control or the hormonal environment leading to a context favourable to obesity development (hypersecretion of corticosteroids, hyperinsulinaemia and hyperleptinaemia and anomalies in the IGF axis). Adipose tissue secretes actively several factors implicated in inflammation, blood pressure, coagulation and fibrinolysis. The programmed development of intra-abdominal obesity after early growth restriction may thus favour higher prevalence of hypertension and cardiovascular diseases. CONCLUSIONS: Abdominal obesity appears in malnourished offspring and is aggravated by early catch-up growth. Higher rates of intra-abdominal obesity observed after growth restriction may participate to hypertension and create atherothrombotic conditions leading to the development of cardiovascular diseases