Determination of Effects of Some Plant Growth Regulators (PGRs) on Changes of Some Isoenzymes in Bean (Phaseolus vulgaris L. cv Terzibaba) at Chilling Temperatures: in gel enzyme assays

This study was conducted to investigate effects of some plant growth regulators (PGRs) such as abscisic acid (ABA) and benzyladenine (BA), on changes of expression of some isoenzymes [superoxide dismutase (SOD), malat dehydrogenase (MDH), glutamate dehydrogenase (GDH), glucose-6-phosphate dehydrogenase (G-6-PDH)] in three vegetative organs (the root, stem, leaf) of bean (Phaseolus vulgaris L) under chilling stress. In order to look into the changes of isoforms of these enzymes under chilling stress and the PGRs, the extracts from vegetative organs were analyzed using native polyacrilamide gel electrophoresis (PAGE). Leaves of bean had four isoforms of SOD and GDH, two isoforms of MDH, five isoforms of G-6-PDH, stems of bean had three isoforms of SOD and MDH, two isoforms of GDH, eight isoforms of G-6-PDH, roots of bean had seven isoforms of SOD, two isoforms of MDH and five isoforms of G-6-PDH in the non chilling stressed-plants. GDH isoform could not be observed in the root of this plant. Expression of some isoforms (GDH-4 in the leaf G-6-PDH-1 in the root, G-6-PDH-6 in the stem, G-6-PDH-12 in the leaf) was stopped by chilling stress. While expression of some isoforms was preferentially enhanced or decreased, some isoforms were not changed by chilling stress and PGRs. In addition, expression of new isoforms (G-6-PDH-10, 12, GDH-2) was occurred by chilling stress and PGRs. These results collectively suggest that changes in isoforms of enzymes may be effective on chilling resistance (CR) and PGRs may have a pivotal role for chilling injury in plants.