Effect of heat stress on polyamine metabolism in proline-over-producing tobacco plants
Effect of heat stress on polyamine metabolism in proline-over-producing tobacco plants
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DOI：
10.1016/j.plantsci.2011.01.016
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发表时间：
2012-01-01
期刊：
影响因子：
5.2
通讯作者：
Vankova, Radomira
中科院分区：
文献类型：
--
作者：
Cvikrova, Milena;Gemperlova, Lenka;Vankova, Radomira
研究了高温胁迫对烟草脯氨酸积累和多胺含量的影响。在组成型过表达脯氨酸生物合成酶Δ 1-吡咯啉-5-羧酸合成酶（P5 CSF 129 A）的修饰基因的烟草植物的上部和下部叶和根中以及在相应的野生型中比较对热胁迫的响应。在热应激的初始阶段（在40 ° C下2小时后），野生型中脯氨酸的积累增加，但转化体中脯氨酸的积累略有下降。脯氨酸过量产生的烟草植株对热胁迫的反应包括游离腐胺和结合腐胺（Put）水平以及游离亚精胺（Spd）、去甲亚精胺（N-Spd）和精胺（Spm）水平在2小时滞后期后的瞬时增加，这与相应生物合成酶活性的刺激相关。二胺氧化酶（DAO）的活性增加，在两种植物基因型，最显着的野生型植物的叶片。多胺氧化酶（PAD）活性在WT植物的根中增加，而在转化体的叶和根中降低。热胁迫6小时后，在转化体中观察到脯氨酸积累，尤其是在下部叶中;在WT植物中观察到更适度的增加。游离和共轭把水平的下降正好与下调的鸟氨酸脱羧酶的活性和显着的刺激DAO活性的转化体的叶和根。PAO活性在根中增加，而在叶中降低。相反，在WT烟草进行6小时的热应激，轻微增加游离和共轭PA水平观察和DAO的活性只增加在根中，PAO活性没有改变，从观察到的值在初始阶段的热应激。6小时的热胁迫对两个基因型上部叶片的丙二醛（MDA;脂质过氧化产物）水平没有影响。经过一段恢复期（25 ℃下2小时），大多数研究的参数显示出与未处理植物中观察到的值相当的值。脯氨酸和多胺的生物合成途径在热胁迫条件下的协调进行了讨论。(C)2011爱思唯尔爱尔兰有限公司保留所有权利。
The effect of heat stress on the accumulation of proline and on the level of polyamines (PAs) in tobacco plants was investigated. Responses to heat stress were compared in the upper and lower leaves and roots of tobacco plants that constitutively over-express a modified gene for the proline biosynthetic enzyme Delta 1-pyrroline-5-carboxylate synthetase (P5CSF129A) and in the corresponding wild-type. In the initial phases of heat stress (after 2 h at 40 degrees C), the accumulation of proline increased in the wild type but slightly decreased in the transformants. The response to heat stress in proline-over-producing tobacco plants involved a transient increase in the levels of free and conjugated putrescine (Put) and in the levels of free spermidine (Spd), norspermidine (N-Spd) and spermine (Spm) after a 2-h lag phase, which correlated with stimulation of the activity of the corresponding biosynthetic enzymes. Diamine oxidase (DAO) activity increased in both plant genotypes, most significantly in the leaves of WT plants. Polyamine oxidase (PAD) activity increased in the roots of WT plants and decreased in the leaves and roots of the transformants. After 6 h of heat stress, proline accumulation was observed in the transformants, especially in the lower leaves; much more modest increase was observed in the WT plants. A decrease in the levels of free and conjugated Put coincided with down-regulation of the activity of ornithine decarboxylase and marked stimulation of DAO activity in the leaves and roots of the transformants. PAO activity increased in the roots of the transformants but decreased in the leaves. Conversely, in WT tobacco subjected to 6 h of heat stress, slight increases in free and conjugated PA levels were observed and the activity of DAO only increased in the roots; PAO activity did not change from the value observed during the initial phase of heat stress. 6 Hours' heat stress had no effect on the level of malondialdehyde (MDA; a product of lipid peroxidation), in the upper leaves of either genotype. After a recovery period (2 h at 25 degrees C), most of the studied parameters exhibited values comparable to those observed in untreated plants. The coordination of the proline and polyamine biosynthetic pathways during heat stress conditions is discussed. (C) 2011 Elsevier Ireland Ltd. All rights reserved.