| 18533529 |
Kang YY, Guo SR, Duan JJ: [Effects of root zone hypoxia on respiratory metabolism of cucumber seedlings roots]. Ying Yong Sheng Tai Xue Bao. 2008 Mar;19(3):583-7.
With the seedlings of Lubachun No. 4, a hypoxia-resistant cultivar, and Zhongnong No. 8, a hypoxia-sensitive cultivar, as test materials, and by the method of solution culture, this paper studied the effects of root zone hypoxia on their roots' respiratory metabolism. The results showed that root zone hypoxia inhibited the tricarboxylic acid (TCA) cycle significantly, But accelerated the anaerobic respiration of cucumber roots. Under root zone hypoxia stress, the decrement of succinic dehydrogenase (SDH) and isocitric dehydrogenase (IDH) activities and the increment of lactate dehydrogenase (LDH) activity and lactate and pyruvate contents were lesser in Lubachun No. 4 than in Zhongnong No. 8 seedlings roots, but conversely, the increment of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) activities and alcohol and alanine contents in Lubachun No. 4 seedlings roots were higher than those in Zhongnong No. 8 seedlings roots. On the 8th day of hypoxia stress, the ADH activity and alcohol and alanine contents increased by 409.30%, 112.13% and 30.64% in Lubachun No. 4 roots and by 110.42%, 31.84% and 4.78% in Zhongnong No. 8 roots, respectively, compared with the control. No significant differences in the alanine aminotransferase (AlaAT) activity and acetaldehyde content were observed between the two cultivars. It was concluded that the acceleration of alcohol fermentation and the accumulation of alanine were in favor of the enhancement of root zone hypoxia tolerance of cucumber roots. |
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