Effect of Seed Treatment with Salicylic Acid on the Carbonic Anhydrase Activity, Photosynthesis Rate, Stomatal Conductance, and Pigments Content in Wheat Leaves at Zinc Excess.

The effect of seed treatment with salicylic acid (SA) on the carbonic anhydrase (CA) activity, photosynthesis rate, stomatal conductance, and pigment content in wheat leaves was studied at an optimal zinc content (2 µM) and zinc excess (1500 µM). It was shown for the first time that the CA activity and stomatal conductance increased upon seed treatment with SA at the optimal zinc content as compared with untreated plants, while the photosynthesis rate was not affected. When zinc was in excess in the root zone, seed treatment with SA decreased the CA activity to a greater extent, but the photosynthesis rate was higher than in untreated plants, apparently due to an increase in the contents of chlorophylls and carotenoids and stomatal conductivity. It was concluded that SA is involved in the protective and adaptive responses of wheat plants to excess environmental zinc along with other nonhormonal factors and hormones.

[Similarities and Differences in Wheat Plant Responses to Low Temperature and Cadmium].

A comparative study was performed on the accumulation of biomass, dynamics of indicators of the activity of photosynthetic apparatus, and cold tolerance in the seedlings of frost-tolerance wheat varieties under the effect of a low hardening temperature and cadmium. It was found that the plant responses to the effects of the stressors studied are similar: an increase in cold tolerance of leaves, slowing rates of plant growth and photosynthesis, and increased non-photochemical fluorescence quenching were observed in both cases. At the same time, it was noted that the plant responses to the actions of low temperature and Cd have certain differences associated with the negative effect of Cd on growth and photosynthetic activity.