Changes in expansin gene expression, IAA content, and extension growth of leaf cells in maize plants subjected to salinity

Effects of salinity of nutrient solution on expression of ZmEXPA1 expansin gene and leaf growth were studied on maize plants (Zea mays L.). Rapid activation of the gene transcription was shown to precede the resumption of extension growth in leaf cells under water deficit induced by NaCl salinity. Auxins were found to accumulate in leaves during salinity treatment, the accumulation being faster than activation of ZmEXPA1 transcription. In addition, exogenous IAA was shown to enhance the gene expression. Our results indicate that the hormone is involved in regulation of cell extension growth at high salinity through the expression of expansin gene.