Pre-soaking wheat (Sakha 92) seeds in GA3 increased the germination potential especially at moderate salinization levels. On the other hand, ABA did not increase the germination potential of the tested seeds at all salinization levels. Fresh and dry matter yields of wheat seedlings decreased at high salinization levels and 90 mM NaCl represented the threshold of salinity. Pre-soaking wheat seeds in GA3 caused marked increases in fresh and dry matter yields of the salinized seedlings. While ABA treatment resulted in non-significant changes in dry matter production of stressed seedlings, the fresh matter production at most salinization levels tended to increase. GA3 or ABA treatment generally increased the soluble carbohydrates and total protein contents of salt stressed seedlings. The stimulatory effect of NaCl salinity on protein synthesis was additionally enhanced as a result of GA3 at all salinization levels or due to ABA treatment especially at high salt levels. The stimulatory effects of salt stress on the accumulation of free amino acids other than proline in the seedlings increased, with the application of GA3, while the activated synthesis of proline was partially attenuated. Application of GA3 was sufficient to attenuate partially the stimulatory effect of NaCl supply on proline biosynthesis, while ABA treatment failed to play this role.

Pre-soaking wheat (Sakha 92) seeds in GA3 increased the germination potential especially at moderate salinization levels. On the other hand, ABA did not increase the germination potential of the tested seeds at all salinization levels. Fresh and dry matter yields of wheat seedlings decreased at high salinization levels and 90 mM NaCl represented the threshold of salinity. Pre-soaking wheat seeds in GA3 caused marked increases in fresh and dry matter yields of the salinized seedlings. While ABA treatment resulted in non-significant changes in dry matter production of stressed seedlings, the fresh matter production at most salinization levels tended to increase. GA3 or ABA treatment generally increased the soluble carbohydrates and total protein contents of salt stressed seedlings. The stimulatory effect of NaCl salinity on protein synthesis was additionally enhanced as a result of GA3 at all salinization levels or due to ABA treatment especially at high salt levels. The stimulatory effects of salt stress on the accumulation of free amino acids other than proline in the seedlings increased, with the application of GA3, while the activated synthesis of proline was partially attenuated. Application of GA3 was sufficient to attenuate partially the stimulatory effect of NaCl supply on proline biosynthesis, while ABA treatment failed to play this role.

Pre-soaking wheat (Sakha 92) seeds in GA3 increased the germination potential especially at moderate salinization levels. On the other hand, ABA did not increase the germination potential of the tested seeds at all salinization levels. Fresh and dry matter yields of wheat seedlings decreased at high salinization levels and 90 mM NaCl represented the threshold of salinity. Pre-soaking wheat seeds in GA3 caused marked increases in fresh and dry matter yields of the salinized seedlings. While ABA treatment resulted in non-significant changes in dry matter production of stressed seedlings, the fresh matter production at most salinization levels tended to increase. GA3 or ABA treatment generally increased the soluble carbohydrates and total protein contents of salt stressed seedlings. The stimulatory effect of NaCl salinity on protein synthesis was additionally enhanced as a result of GA3 at all salinization levels or due to ABA treatment especially at high salt levels. The stimulatory effects of salt stress on the accumulation of free amino acids other than proline in the seedlings increased, with the application of GA3, while the activated synthesis of proline was partially attenuated. Application of GA3 was sufficient to attenuate partially the stimulatory effect of NaCl supply on proline biosynthesis, while ABA treatment failed to play this role.

Nostoc rivulare was grown in batch cultures under controlled CO2 and NO3 – concentrations to modulate the photosynthetic source:sink relationship. Increasing CO2 supply accelerated the accumulation of chlorophyll (Chl) a, i.e., supplemental CO2 combined with double concentrations of NO3 – more than doubled the amounts of Chl a relative to those of the original medium. Photosynthetic oxygen evolution and respiratory oxygen uptake were both enhanced by elevated CO2 and NO3 –. Contents of soluble sugars and starch (total non-structural saccharides) as well as insoluble saccharides (structural fraction) were affected by altering CO2-NO3 – combinations. Uptake as well as reduction of either NO3 – or NO2 – was inhibited by CO2 deprivation. Expanding the sink size via increasing NO3 – supply enhanced photosynthesis and thus the sink (NO3 –) acted as a feed forward stimulator of the source (photosynthesis). The regulatory role of nitrate on photosynthesis was most influential in CO2-deprived cultures since it could enhance photosynthesis to higher levels than CO2-supplemented, nitrate-free cultures.

Nostoc rivulare was grown in batch cultures under controlled CO2 and NO3 – concentrations to modulate the photosynthetic source:sink relationship. Increasing CO2 supply accelerated the accumulation of chlorophyll (Chl) a, i.e., supplemental CO2 combined with double concentrations of NO3 – more than doubled the amounts of Chl a relative to those of the original medium. Photosynthetic oxygen evolution and respiratory oxygen uptake were both enhanced by elevated CO2 and NO3 –. Contents of soluble sugars and starch (total non-structural saccharides) as well as insoluble saccharides (structural fraction) were affected by altering CO2-NO3 – combinations. Uptake as well as reduction of either NO3 – or NO2 – was inhibited by CO2 deprivation. Expanding the sink size via increasing NO3 – supply enhanced photosynthesis and thus the sink (NO3 –) acted as a feed forward stimulator of the source (photosynthesis). The regulatory role of nitrate on photosynthesis was most influential in CO2-deprived cultures since it could enhance photosynthesis to higher levels than CO2-supplemented, nitrate-free cultures.

Nostoc rivulare was grown in batch cultures under controlled CO2 and NO3 – concentrations to modulate the photosynthetic source:sink relationship. Increasing CO2 supply accelerated the accumulation of chlorophyll (Chl) a, i.e., supplemental CO2 combined with double concentrations of NO3 – more than doubled the amounts of Chl a relative to those of the original medium. Photosynthetic oxygen evolution and respiratory oxygen uptake were both enhanced by elevated CO2 and NO3 –. Contents of soluble sugars and starch (total non-structural saccharides) as well as insoluble saccharides (structural fraction) were affected by altering CO2-NO3 – combinations. Uptake as well as reduction of either NO3 – or NO2 – was inhibited by CO2 deprivation. Expanding the sink size via increasing NO3 – supply enhanced photosynthesis and thus the sink (NO3 –) acted as a feed forward stimulator of the source (photosynthesis). The regulatory role of nitrate on photosynthesis was most influential in CO2-deprived cultures since it could enhance photosynthesis to higher levels than CO2-supplemented, nitrate-free cultures.

Efficient de novo shoot organogenesis from hypocotyl and cotyledons was studied under NaCl-salinity conditions and in a salinity-calcium combination. Sodium chloride inhibited shoot regeneration markedly at 100 and 150 mM NaCl. Both the fresh and dry weight were also reduced. The mineral contents (Na, K and Ca) of hypocotyl and cotyledonary cultures were disturbed at high levels of NaCl salinity. The osmotic potential (Ř s) was raised in hypocotyl and cotyledonary cultures in MS medium as the NaCl salinity level increased. Calcium enhanced shoot regeneration in hypocotyls and cotyledonary cultures, especially at the highest salinity level (150 mM NaCl). This calcium-induced counteraction of the harmful effect of NaCl may be due to the reduced uptake of Na and to the elevated water content of hypocotyls and cotyledonary cultures under Na-Ca combination. wall rigidity.

Efficient de novo shoot organogenesis from hypocotyl and cotyledons was studied under NaCl-salinity conditions and in a salinity-calcium combination. Sodium chloride inhibited shoot regeneration markedly at 100 and 150 mM NaCl. Both the fresh and dry weight were also reduced. The mineral contents (Na, K and Ca) of hypocotyl and cotyledonary cultures were disturbed at high levels of NaCl salinity. The osmotic potential (Ř s) was raised in hypocotyl and cotyledonary cultures in MS medium as the NaCl salinity level increased. Calcium enhanced shoot regeneration in hypocotyls and cotyledonary cultures, especially at the highest salinity level (150 mM NaCl). This calcium-induced counteraction of the harmful effect of NaCl may be due to the reduced uptake of Na and to the elevated water content of hypocotyls and cotyledonary cultures under Na-Ca combination. wall rigidity.

Efficient de novo shoot organogenesis from hypocotyl and cotyledons was studied under NaCl-salinity conditions and in a salinity-calcium combination. Sodium chloride inhibited shoot regeneration markedly at 100 and 150 mM NaCl. Both the fresh and dry weight were also reduced. The mineral contents (Na, K and Ca) of hypocotyl and cotyledonary cultures were disturbed at high levels of NaCl salinity. The osmotic potential (Ř s) was raised in hypocotyl and cotyledonary cultures in MS medium as the NaCl salinity level increased. Calcium enhanced shoot regeneration in hypocotyls and cotyledonary cultures, especially at the highest salinity level (150 mM NaCl). This calcium-induced counteraction of the harmful effect of NaCl may be due to the reduced uptake of Na and to the elevated water content of hypocotyls and cotyledonary cultures under Na-Ca combination. wall rigidity.

The effect of salicylic acid (SA: 0.5 mM) on the plant growth, copper accumulation, Cu-bound proteins and protein pattern in roots and shoots of Helianthus annuus plants under Cu stress (5 mg L-1) was studied. Cu stress reduced the fresh and dry weights of sunflower plants. Cu markedly accumulated in Cu-stressed plants. However, this accumulation of Cu was higher in roots than in shoots. Chromatography of cell free extract of Cu-binding proteins of cu-stressed plants revealed three main protein peaks in roots and four peaks in leaves. The main peak for copper is coincident with protein of molecular weight of 75 kDa and contains about 89.40 and 80.84% of the total copper in the soluble fraction in roots and leaves, respectively. Proteins pattern shows that, Cu-stress induced the synthesis of new polypeptides of 178 and 97 kDa in plant roots and 105, 81 kDa in case of plant leaves. SA increased the fresh and dry weights of Cu-stressed plants. SA lowered the Cu content both in the roots and shoots of Cu-stressed plants. This was associated an increase in the endogenous SA content in the two organs. Cu plus SA treatment revealed 4 protein peaks with molecular weights about 175, 130, 75 and 35 kDa in roots and 175, 130, 100 and 45 kDa in case of leaves. The main peak for copper is coincident with protein of molecular weight 75 kDa in roots and 100 kDa in leaves, retaining about 82.90 and 74.72% of the total copper in the soluble fraction. Under Cu stress, SA induced the synthesis of 5 new polypeptides with molecular weight ranged from 204 to 26 kDa in roots and 4 new polypeptides ranged from 189 to 6 kDa in case of leaves. The results indicate that salicylic acid can alleviate the adverse effects of copper on the growth of sunflower plants by interfering of SA in translocation of Cu and/or increasing Cu-binding proteins in sunflower