Effect of waterlogging on carbohydrate metabolism in pigeon pea (Cajanus cajan L.): Upregulation of sucrose synthase and alcohol dehydrogenase
Effect of waterlogging on carbohydrate metabolism in pigeon pea (Cajanus cajan L.): Upregulation of sucrose synthase and alcohol dehydrogenase
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DOI：
10.1016/j.plantsci.2008.07.013
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发表时间：
2008-11-01
期刊：
影响因子：
5.2
通讯作者：
Meena, R. C.
中科院分区：
文献类型：
--
作者：
Kumutha, D.;Sairam, R. K.;Meena, R. C.
本研究的目的是研究根系碳水化合物水平和代谢的作用，在耐涝性的对比木豆基因型。以4种木豆（Cajanus cajan）基因型为材料，对2种耐涝基因型（ICPL 84023和ICP 301）和2种感涝基因型（ICP 7035和Pusa 207）进行了耐涝胁迫试验。通过将具有25天龄植物的盆放置在充满水的塑料槽中来进行涝渍处理。涝渍导致叶面积、干物质、叶片相对含水量、叶绿素含量以及根和叶组织膜稳定性指数下降。ICP 7035和Pusa 207的下降幅度大于ICPL 84023和ICP 301，它们在6天淹水植物恢复期间也遭受了几乎100%的死亡率。耐受基因型ICPL 84023和ICP 301显示出比ICP 7035和Pusa 207更高的总糖、还原糖和非还原糖含量。涝渍导致所有基因型的总糖和非还原糖以及ICP 7035和Pusa 207的还原糖含量下降，而ICPL 84023和ICP 301的还原糖含量增加。还原糖含量的变异与蔗糖合成酶活性的变化趋势一致。与ICP 7035和Pusa 207相比，ICPL 84023和ICP 301的总糖和非还原糖下降较少，还原糖和蔗糖合成酶（SuSy）活性增加较多。淹水导致乙醇脱氢酶（ADH）活性升高，且ICPL 84023和ICP 301的升高幅度高于ICP 7035和Pusa 207。在24 h淹水条件下通过RT-PCR进行的基因表达研究表明，ICPL 84023根中ADH和SuSy的表达增强，而在ICP 7035中，对照或处理植物的表达水平没有变化。感涝基因型ICP 7035在ADH启动子CAAT盒区域发生突变，可能是导致ADH基因表达、活性和对涝渍敏感性降低的原因。结果表明，木豆基因型ICPL 84023和ICP 301的耐涝性取决于根系中是否有足够的糖储备，蔗糖合成酶的活性为糖酵解活性提供还原糖，ADH为糖酵解的继续循环提供还原糖，糖酵解是低氧下的主要能量来源。这反映在ICPL 84023和ICP 301中叶片中更好的RWC和Chl含量以及叶片和根组织的膜稳定性。(C)2008爱思唯尔爱尔兰有限公司保留所有权利。
The objective of this study was to examine the role of root carbohydrate levels and metabolism in the waterlogging tolerance of contrasting pigeon pea genotypes. An experiment was conducted with 4 pigeon pea (Cajanus cajan) genotypes, 2 tolerant (ICPL 84023 and ICP 301) and 2 susceptible (ICP 7035 and Pusa 207) to waterlogging stress. Waterlogging treatment was given by placing pots with 25 days old plants in plastic troughs filled with water. Waterlogging resulted in decrease in leaf area, dry matter, relative water content and chlorophyll content in leaves, and membrane stability index in root and leaf tissues. The decline was greater in ICP 7035 and Pusa 207, which also suffered almost 100% mortality during recovery of 6 days waterlogged plants, than ICPL 84023 and ICP 301. Tolerant genotypes ICPL 84023 and ICP 301 showed higher total, reducing and non-reducing sugars content than ICP 7035 and Pusa 207. Waterlogging resulted in decline in total and non-reducing sugars in all the genotypes and reducing sugars in ICP 7035 and Pusa 207, while the content of reducing sugars increased in ICPL 84023 and ICP 301. The pattern of variation in reducing sugar content in the 4 genotypes was parallel to sucrose synthase activity. ICPL 84023 and ICP 301 also showed fewer declines in total and non-reducing sugars and greater increase in reducing sugar and sucrose synthase (SuSy) activity than ICP 7035 and Pusa 207. Waterlogging resulted in increase in alcohol dehydrogenase (ADH) activity, and increase was higher in ICPL 84023 and ICP 301 than ICP 7035 and Pusa 207. Gene expression studies done by RT-PCR under 24 h waterlogging showed enhanced expression of ADH and SuSy in the roots of ICPL 84023, while in ICP 7035 there was no change in expression level in control or treated plants. The susceptible genotype ICP 7035 showed mutation in the CAAT box region of the ADH promoter, which could be the possible reason of lower ADH gene expression, activity and sensitivity to waterlogging. The results suggest that waterlogging tolerance of pigeon pea genotypes ICPL 84023 and ICP 301 depends on the availability of sufficient sugar reserve in the roots, activity of sucrose synthase to provide reducing sugars for glycolytic activity and ADH for the recycling of NADH for the continuation of glycolysis, the major source of energy under hypoxia. This was reflected in better RWC and Chl content in leaves, and membrane stability of leaf and root tissue in ICPL 84023 and ICP 301. (C) 2008 Elsevier Ireland Ltd. All rights reserved.