文摘
The content of transcripts of HvHMA2 and HvHMA3 genes in roots and leaves of 3-day-old (the stage of seed germination) and 7-day-old (the seedling stage) barley (Hordeum vulgare L., cv. Zazerskii 85) seedlings in the presence of cadmium ions (100 μM) was studied. Some organ-specific and age-related differences in the level of mRNAs of studied genes were identified. So, after a 4-day exposure of plants to a solution containing cadmium ions, the level of transcripts of HvHMA3 gene increased in the roots of 3-day-old seedlings, contributing to the sequestration of toxic ions in the vacuole. The level of HvHMA2 transcripts increased stronger in 7-day-old seedlings, especially in the leaves, which apparently may lead to an increased inflow of the metal ions in the phloem and to an activation of its translocation from the leaves to the roots. The observed decrease in this gene transcripts in the roots contributed in its turn to a limitation of cadmium transport to the shoots. A conclusion about the possible involvement of HvHMA2 gene in an increase of resistance of 7-day-old barley plants to cadmium was drawn based on the comparison of gene transcripts and the resistance of seedlings of different ages to this metal.