The effect of drought and salt stresses on the water soluble carbohydrate content in wheat (Triticum aestivum L.) seedlings was examined to characterize the involvement of major sugar components in the adaptive processes. Hydroponically grown seedlings of four wheat varieties differing in drought and salt tolerance were exposed to consecutive water (polyethylene glycol, PEG) and salinity (NaCl) stresses. Total water‐soluble carbohydrate (WSC), glucose, fructose, sucrose, and fructan content of stems (non‐photosynthetic tissue) were determined. Tolerant genotypes accumulated more soluble carbohydrate than did sensitive ones. Both ionic and non‐ionic stresses increased the concentration of reducing sugars, sucrose, and fructans. Drought tolerant varieties accumulated sucrose to a significantly greater level than did sensitive ones under non‐ionic stress condition. Changes in fructan content of plants after transfer from PEG to NaCl containing solutions were genotype dependent, increasing in salt tolerant and decreasing in salt sensitive cultivars. These results indicate that WSC might be a useful marker for selecting genotypes that are more drought or salt tolerant. The type of sugar comprising the increase in WSC appears to be a less reliable marker since the initial response was an increase in monosaccharides and the delayed response was an increase in fructan.

No abstract

No abstract

Several studies have described high correlation of salivary and blood lactate level during exercise. Measuring the effectiveness and intensity of training, lactate concentration in blood, and lately in saliva are used.The aim of our study was to evaluate the correlation between the concentration and timing of salivary and blood lactate level in endurance athletes and non-athletes after a maximal treadmill test, and to identify physiological and biochemical factors affecting these lactate levels.Sixteen volunteers (8 athletes and 8 non-athletes) performed maximal intensity (Astrand) treadmill test. Anthropometric characteristics, body composition and physiological parameters (heart rate, RR-variability) were measured in both studied groups. Blood and whole saliva samples were collected before and 1, 4, 8, 12, 15, 20 min after the exercise test. Lactate level changes were monitored in the two groups and two lactate peaks were registered at different timeperiods in athletes. We found significant correlation between several measured parameters (salivary lactate - total body water, salivary lactate - RR-variability, maximal salivary lactate - maximal heart rate during exercise, salivary- and blood lactate -1 min after exercise test). Stronger correlation was noted between salivary lactate and blood lactate in athletes, than in controls.

No abstract