硝普钠对铝胁迫下黑麦和小麦根尖线粒体功能的影响

Effects of Sodium Nitroprusside on Mitochondrial Function of Rye and Wheat Root Tip under Aluminum Stress

硝普钠(SNP)能够缓解铝对黑麦和小麦根伸长生长的抑制效应。铝降低黑麦和小麦的呼吸速率和P/O、OPR、R3、R4、RCR值以及线粒体膜H+-ATP酶、H+-PP酶、Na+-K+-ATP酶、Ca2+-ATP酶、Mg2+-ATP酶活性,而SNP则能提高铝胁迫下呼吸速率、P/O、OPR、R3、R4、RCR值和这些酶活性。说明铝胁迫导致黑麦和小麦根尖细胞线粒体呼吸功能受损,氧化磷酸化解耦联。黑麦受损程度较小麦低,具有较强耐铝能力。SNP作为一氧化氮(NO)的供体,推测NO可以有效减轻铝胁迫导致的小麦根尖线粒体呼吸功能障碍,从而能够缓解铝毒害。

Sodium nitroprusside （SNP） could ameliorate the inhibition effect of Al on root growth of rye （Secale cereale L. cv. King） and wheat （Triticum aestivum L. cv. Jinmai47） （Table 1）. Respiratory rate （Fig.10）, P/O （Fig.9）, OPR （oxygenated phosphate rate） （Fig. 11）, R3 （oxygen consumption rate with ADP and substrate present） （Fig.6）, R4 （oxygen consumption rate with substrate） （Fig.7） and RCR （respiratory control ratio, R3/R4） （Fig.8） of root tips from rye and wheat decreased, as well as the activities of H^＋-ATPase （Fig. 1）, H^＋-PPase （Fig.2）, Na^＋-K^＋-ATPase （Fig.3）, Ca^2＋-ATPase （Fig.4） and Mg^2＋-ATPase （Fig.5）, but they increased with SNP treatment. It showed that mitochondrial respiratory functions of root tips from rye and wheat were damaged, phosphorylation was un-coupled by Al, but that of rye was less than that of wheat. Rye has high Al-resistance ability than wheat. SNP is one of donor of NO, it is suggested that NO can ameliorate remarkably respiratory dysfunction resulted from Al stress, so that NO can ameliorate the inhibition effect of Al on plant growth.