Department of Botany, Aligarh Muslim University, India.
Arch Environ Contam Toxicol. 2011 Jan;60(1):68-76. doi: 10.1007/s00244-010-9535-0. Epub 2010 May 13.
Seeds of five wheat (Triticum aestivum) cultivars (PBW-373, UP-2338, DL-LOK-01, DL-373, and HD-2338) were sown in earthen pots and 10-day-old seedlings were exposed to 0, 50, and 100 μM of nickel (Ni) in the form of nickel chloride. At the 20-day stage, seedlings were sprayed with 0.01 μM of 28-homobrassinolide (HBL). The results of the experiment at the 30-day stage revealed a decline in the dry mass per plant, leaf area, leaf water potential, and net photosynthetic rate with concomitant decline in the activities of various enzymes (viz. carbonic anhydrase and nitrate reductase) with an increasing concentration of Ni. However, an increase in proline content and the activities of catalase, peroxidase, and superoxide dismutase was observed as a result of an increase in Ni concentration. Moreover, the treatment of these stressed plants with HBL enhanced the activities of carbonic anhydrase and nitrate reductase, catalase, peroxidase, and superoxide dismutase. The proline content in the leaves also increased, which is known to act as an osmolyte and reactive oxygen species scavenger. The toxic effects generated by Ni were ameliorated by HBL through an improved antioxidant system and osmolyte. Moreover, improvement of photosynthetic parameters and growth characteristics further strengthen our belief that HBL acted as a potent stress alleviator.
五种小麦（Triticum aestivum）品种（PBW-373、UP-2338、DL-LOK-01、DL-373 和 HD-2338）的种子播种在土盆中，10 天大的幼苗在氯化镍的形式下暴露于 0、50 和 100μM 的镍（Ni）。在 20 天阶段，用 0.01μM 的 28-高油菜素内酯（HBL）喷洒幼苗。在 30 天阶段的实验结果表明，随着 Ni 浓度的增加，植物每株的干质量、叶面积、叶片水势和净光合速率下降，同时各种酶（即碳酸酐酶和硝酸还原酶）的活性下降。然而，由于 Ni 浓度的增加，脯氨酸含量和过氧化氢酶、过氧化物酶和超氧化物歧化酶的活性增加。此外，用 HBL 处理这些受胁迫的植物，提高了碳酸酐酶和硝酸还原酶、过氧化氢酶、过氧化物酶和超氧化物歧化酶的活性。叶片中的脯氨酸含量也增加了，已知脯氨酸作为渗透调节剂和活性氧清除剂。HBL 通过改善抗氧化系统和渗透调节剂减轻了 Ni 产生的毒性作用。此外，光合参数和生长特性的改善进一步加强了我们的信念，即 HBL 作为一种有效的胁迫缓解剂。
