Modulation of delta-Aminolevulinic Acid Dehydratase Activity by the Sorbitol-Induced Osmotic Stress in Maize Leaf Segments

作者：Jain M^*; Tiwary S; Gadre R

来源：Biochemistry-Moscow, 2018, 83(1): 32-36.

DOI：10.1134/S0006297918010042

• aminolevulinic acid dehydratase activity
• osmotic stress
• sorbitol
• maize

Osmotic stress induced with 1 M sorbitol inhibited delta-aminolevulinic acid dehydratase (ALAD) and aminolevulinic acid (ALA) synthesizing activities in etiolated maize leaf segments during greening; the ALAD activity was inhibited to a greater extent than the ALA synthesis. When the leaves were exposed to light, the ALAD activity increased for the first 8 h, followed by a decrease observed at 16 and 24 h in both sorbitol-treated and untreated leaf tissues. The maximum inhibition of the enzyme activity was observed in the leaf segments incubated with sorbitol for 4 to 8 h. Glutamate increased the ALAD activity in the in vitro enzymatic preparations obtained from the sorbitol-treated leaf segments; sorbitol inhibited the ALAD activity in the preparations from both sorbitol-treated and untreated leaves. It was suggested that sorbitol-induced osmotic stress inhibits the enzyme activity by affecting the ALAD induction during greening and regulating the ALAD steady-state level of ALAD in leaf cells. The protective effect of glutamate on ALAD in the preparations from the sorbitol-treated leaves might be due to its stimulatory effect on the enzyme.

• 出版日期2018-1