Dinakar N, Nagajyothi P C, Suresh S, Damodharam T, Suresh C
Department of Environmental Sciences, College of Mathematical and Physical Sciences, Sri Venkateswara University, Tirupati, India.
J Environ Biol. 2009 Mar;30(2):289-94.
The groundnut, Arachis hypogaea seedlings, when grown in pot cultures for 10-25 days at 25, 50, 100 microM CdCl2, showed a marked decline in growth compared to control. Similar trend was observed for nitrate reductase (NR) and nitrite reductase (NiR) activities whereas proline, peroxidase (POD) and catalase (CAT) showed increasing trend when observed on the 10th day of the experiment. Changes have occurred in the physiological and biochemical activities which are observed even at low Cd levels (25 microM). At 100 microM concentration, with increase in experimental days, Cd has imposed drastic decrease in leaf and stem respectively where nitrate reductase has varied from 20.87-79.41 and 29.11-72.91% and nitrite reductase 21.66-79.41 and 43.58-75.92% respectively. Contrastingly Cd treated plant tissues showed an increase in proline 111.2-159.87% (percentage changes) and 131.23-212.16% for leaves and stems respectively. In addition cadmium caused significant changes in the activity of antioxidative enzymes, peroxidase 48.12-72.19% in leaf and 37.71-75.25% in stem and catalase 64.86-143.92% in leaf and 129.13-214.74% in stem as compared to control. The study concludes that the activities of NR, NiR, proline, POD, CAT are inhibited suggesting that Arachis hypogaea seedlings are under Cd stress affecting their growth.
花生（Arachis hypogaea）幼苗在盆栽条件下，于25、50、100微摩尔/升的CdCl₂浓度下培养10 - 25天，与对照相比，生长显著下降。硝酸还原酶（NR）和亚硝酸还原酶（NiR）的活性呈现类似趋势，而在实验第10天观察到脯氨酸、过氧化物酶（POD）和过氧化氢酶（CAT）呈上升趋势。即使在低镉水平（25微摩尔/升）下，生理和生化活性也发生了变化。在100微摩尔/升浓度下，随着实验天数增加，镉分别使叶片和茎干大幅减少，其中硝酸还原酶的变化分别为20.87 - 79.41%和29.11 - 72.91%，亚硝酸还原酶分别为21.66 - 79.41%和43.58 - 75.92%。相反，镉处理的植物组织中脯氨酸含量增加，叶片中增加了111.2 - 159.87%（百分比变化），茎干中增加了131.23 - 212.16%。此外，与对照相比，镉导致抗氧化酶活性发生显著变化，叶片中过氧化物酶活性变化为48.12 - 72.19%，茎干中为37.71 - 75.25%；叶片中过氧化氢酶活性变化为64.86 - 143.92%，茎干中为129.13 - 214.74%。该研究得出结论，NR、NiR、脯氨酸、POD、CAT的活性受到抑制，表明花生幼苗处于镉胁迫下，影响其生长。
