土壤紧实胁迫对黄瓜根系呼吸代谢的影响

Effects of soil compaction stress on respiratory metabolism of cucumber root

用容重分别为1.20和1.55g·cm-3的土壤进行盆栽试验,研究了土壤紧实胁迫对‘津春4号’黄瓜根系呼吸代谢的影响.结果表明:土壤紧实胁迫条件下,黄瓜根系中丙酮酸脱羧酶、乙醇脱氢酶和乳酸脱氢酶活性显著提高;无氧呼吸主要产物(乙醇、乙醛和乳酸)含量显著升高;参与有氧呼吸的苹果酸脱氢酶、琥珀酸脱氢酶和异柠檬酸脱氢酶活性显著下降,丙酮酸和琥珀酸含量显著提高,苹果酸含量显著下降.说明在土壤紧实胁迫条件下,黄瓜根系的有氧呼吸受到显著抑制,无氧呼吸过程加强.

A pot experiment with cucumber cultivar ＂Jingchun 4＂ was conducted to study the effects of soil compaction stress on the respiratory metabolism of cucumber root. Two treatments were installed, i. e. , soil bulk densities 1.20 and 1.55 g .cm-3 Under soil compaction stress, the activities of root pyruvate decarboxylase, alcohol dehydrogenase, and lactate dehydrogenase and the contents of root anaerobic respiration products alcohol, acetaldehyde, and lactate increased signifi- cantly, while the activities of the key enzymes involved in root aerobic respiration, including malate dehydrogenase, succinate dehydrogenase, and isocitrate dehydrogenase, decreased significantly, root pyruvate and succinate contents had significant increase, whereas root malate content decreased significantly. All the results illustrated that under soil compaction stress, the aerobic respiration of cucumber root was inhibited, while its anaerobic respiration was promoted.