Cold- or heat-tolerance of leaves and roots in perennial ryegrass determined by 1H-NMR
Cold- or heat-tolerance of leaves and roots in perennial ryegrass determined by 1H-NMR
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DOI：
10.1626/pps.7.118
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发表时间：
2004-06-01
影响因子：
2.5
通讯作者：
Fukuyama, M
中科院分区：
文献类型：
--
作者：
Iwaya-Inoue, M;Matsui, R;Fukuyama, M
采用H-1-NMR研究了多年生黑麦草（Lolium perenne L.）叶片和根系在冷热胁迫下水分的动态变化。温度低于0℃时，叶片的核磁共振自旋晶格弛豫时间（T-2）呈线性下降，但随着温度的降低而增加。随着温度从20℃降至-20℃，叶片的自旋-自旋弛豫时间（72）增加。在-25℃时，叶片中长部（与液泡相关）的T-2值降至600mus左右，而短部的T-2值降至10mus左右，长部的信号强度相对值降至0.2左右。在-10℃时，根中两组分的T值降至1ms左右。从T-2和电解质泄漏判断，叶和根的液泡区和细胞质区在这些温度下都冻结了。在20 ~ 40℃温度范围内，随着温度的升高，叶片的T-1略有下降，但随着温度的升高，T-1急剧下降。另一方面，随着温度从20℃升高到50℃，根系的T-1呈线性下降。暴露于上述高温胁迫下的叶片电解质泄漏水平较低，表明膜未受到严重损伤。综上所述，T-1和T-2阿伦尼乌斯图分析是评价多年生黑麦草器官对温度胁迫初步反应的一种灵敏、无创的方法。
Dynamic states of water in the leaves and roots of perennial ryegrass (Lolium perenne L.) exposed to cold and heat stresses were studied by using H-1-NMR. NMR spin-lattice relaxation times (T-2) of leaves in Arrhenius plots linearly decreased but increased as temperature decreased below 0degreesC. However, spin-spin relaxation times (72) of the leaves increased as temperature decreased from 20 to -20degreesC. The T-2 value of the long fraction (associated with vacuole) in leaves decreased to about 600mus at -25degreesC, but that of the short fraction was about 10mus, and the relative value of signal intensity of the long fraction decreased to about 0.2 at -25degreesC. The T, values of the two fractions in roots decreased to about 1ms at -10degreesC. judging from T-2 and electrolyte leakage, both vacuolar and cytoplasmic compartments of leaves and roots froze at these temperatures. T-1 of the leaves decreased slightly as temperature increased from 20 to 40degreesC but greatly decreased as temperature increased further. On the other hand, T-1 of the roots decreased linearly as temperature increased from 20 to 50degreesC. The levels of electrolyte leakage from leaves exposed to the above beat stress was low suggesting that membrane was not severely injured. In conclusion, analysis of Arrhenius plots of T-1 and T-2 is a sensitive and non-invasive method to evaluate primary responses of perennial ryegrass organs to the temperature stresses.