Effect of root-applied spermidine on growth and respiratory metabolism in roots of cucumber (Cucumis sativus) seedlings under hypoxia
Effect of root-applied spermidine on growth and respiratory metabolism in roots of cucumber (Cucumis sativus) seedlings under hypoxia
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根部施用亚精胺对缺氧条件下黄瓜幼苗生长及呼吸代谢的影响
DOI：
10.1134/s1021443710050079
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发表时间：
2010-09
影响因子：
1.4
通讯作者：
中科院分区：
文献类型：
--
作者：
研究了外源亚精胺（Spd）在低氧营养液中对黄瓜（Cucumis sativus L.）幼苗进行了调查。水培黄瓜幼苗在对照和低氧营养液中添加和不添加浓度为0.05 mM的亚精胺（Spd），根区低氧（DO为1 mg/l）显著抑制了三羧酸循环（TCAC）中的关键酶琥珀酸脱氢酶（SDH）和异柠檬酸脱氢酶（IDH）的活性。与此相反，参与发酵过程的酶，如丙酮酸脱羧酶（PDC），乙醇脱氢酶（ADH），乳酸脱氢酶（LDH）和丙氨酸氨基转移酶（AlaAT）的活性显着增加。因此，低氧胁迫下，黄瓜幼苗根系的有氧呼吸受到抑制，根系的发酵作用增强，ATP含量降低，从而抑制了幼苗的干重。此外，低氧胁迫下黄瓜幼苗根系中游离态、可溶性结合态和不溶性结合态腐胺（Put）、Spd和精胺（Spm）含量显著增加。有趣的是，应用亚精胺缺氧根明显抑制积累的自由把，相反，促进增加游离亚精胺和精胺，以及可溶性共轭和不溶性结合把，亚精胺，和精胺含量。从这些数据中，我们推断，外源Spd促进转化游离Put的游离Spd和Spm，可溶性共轭和不溶性结合PAs缺氧胁迫。外源亚精胺处理低氧根后，LDH、PDC和ADH活性受到抑制，而SDH和IDH活性则得到增强。结果表明，低氧胁迫增强了黄瓜幼苗根系的有氧呼吸，抑制了根系的发酵代谢，从而增加了ATP含量，缓解了低氧胁迫对幼苗干重的抑制作用。结果表明，在低氧营养液中施用Spd可促进游离Put向Spd和Spm以及可溶性结合态和不溶性结合态多胺的转化，进一步提高IDH和SDH活性，抑制乙醇发酵和乳酸发酵，从而提高ATP含量，增强黄瓜对根区低氧的耐受性。
The effects of exogenous spermidine (Spd) application to hypoxic nutrient solution on the contents of endogenous polyamines (PAs) and respiratory metabolism in the roots of cucumber (Cucumis sativus L.) seedlings were investigated. Cucumber seedlings were grown hydroponically in control and hypoxic nutrient solutions with and without addition of Spd at a concentration of 0.05 mM. The activities of key enzymes involved in the tricarboxylic acid cycle (TCAC), such as succinate dehydrogenase (SDH) and isocitrate dehydrogenase (IDH), were significantly inhibited under root-zone hypoxia with dissolved oxygen (DO) at 1 mg/l. In contrast, the activities of enzymes involved in the process of fermentation, such as pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH), lactate dehydrogenase (LDH), and alanine aminotransferase (AlaAT), were significantly increased. Thus, aerobic respiration was inhibited and fermentation was enhanced in the roots of cucumber seedlings as a result of decreasing ATP content to inhibit the dry weight of seedlings under hypoxic stress. Moreover, the contents of free, soluble conjugated, and insoluble bound putrescine (Put), Spd, and spermine (Spm) in the roots of cucumber seedlings were significantly increased under hypoxia stress. Interestingly, application of Spd to hypoxic roots markedly suppressed the accumulation of free Put and, in contrast, promoted an increase in free Spd and Spm, as well as soluble conjugated and insoluble bound Put, Spd, and Spm contents. From these data, we deduced that exogenous Spd promotes the conversion of free Put into free Spd and Spm, and soluble conjugated and insoluble bound PAs under hypoxia stress. Furthermore, the activities of LDH, PDC, and ADH were suppressed and, in contrast, the activities of SDH and IDH were enhanced by application of exogenous Spd to hypoxic roots. As a result, aerobic respiration was enhanced but fermentation metabolism was inhibited in the roots of cucumber seedlings, leading to an increase in ATP content to alleviate the inhibited dry weight of seedlings due to hypoxia stress. These results suggest that application of Spd to hypoxic nutrient solution promoted conversion of free Put into free Spd and Spm as well as soluble conjugated and insoluble bound PAs, further enhanced IDH and SDH activities, and inhibited ethanol fermentation and lactate fermentation, resulting in increased ATP content and eventually enhanced tolerance of cucumber plants to root-zone hypoxia.
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DOI：
10.2503/jjshs.73.337
发表时间：
2004-07
影响因子：
--
作者：
K. Nada;Etsuko Iwatani;T. Doi;S. Tachibana
通讯作者：
K. Nada;Etsuko Iwatani;T. Doi;S. Tachibana
影响因子：
6.4
作者：
Kato-Noguchi, H
通讯作者：
Kato-Noguchi, H
影响因子：
5.2
作者：
B. Waie;M. Rajam
通讯作者：
B. Waie;M. Rajam
DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
Sun Jin
通讯作者：
Sun Jin
影响因子：
7.4
作者：
R. Krishnamurthy;K. A. Bhagwat
通讯作者：
R. Krishnamurthy;K. A. Bhagwat