Changes in the power spectrum of electrical signals in maize leaf induced by osmotic stress  

作　　者：ZHANG XiaoHui YU NingMei XI Gang MENG XiaoLi 

机构地区：[1]Faculty of Automation and Information Engineering,Xi'an University of Technology,Xi'an 710048,China [2]Department of Applied Physics,Xi'an University of Technology,Xi'an 710048,China

出　　处：《Chinese Science Bulletin》2012年第4期413-420,共8页

基　　金：supported by the National Natural Science Foundation of China(50977079);the Scientific Research Plan Project of Shaanxi Education Department(09JK667)

摘　　要：To quantify the characteristics of the power spectrum of plant electrical signals, we defined the following concepts:spectral edge frequency (SEF), spectral center frequency (SCF), power index (PI) and power spectral entropy (PSE). These parameters were used to examine and quantify changes in the power spectrum of electrical signals in maize leaves under osmotic stress. In the absence of osmotic stress, the SEF of the electrical signal in maize leaves was approx. 0.2 Hz and the SCF was approx. 0.1 Hz. The electrical signal in maize leaves was mainly a slow wave signal with a frequency of 0-0.1 Hz. After 2 h osmotic stress, the SEF and SCF of the electrical signal increased to higher frequencies. The proportion of the fast wave frequency also increased to 0.1-0.2 Hz, resulting in a dramatic increase in PSE. We also found that the changes in PSE and SCF were significantly correlated during osmotic stress. We propose that the changes in the PSE and SCF in maize leaves can be used as a sensitive signal indicating water deficit in leaf cells under osmotic stress. Thus, measurement of SCF or PSE of electrical signals in maize leaves could be used to develop early warning and rapid diagnosis techniques for the water demands of plants.To quantify the characteristics of the power spectrum of plant electrical signals, we defined the following concepts： spectral edge frequency （SEF）, spectral center frequency （SCF）, power index （PI） and power spectral entropy （PSE）. These parameters were used to examine and quantify changes in the power spectrum of electrical signals in maize leaves under osmotic stress. In the absence of osmotic stress, the SEF of the electrical signal in maize leaves was approx. 0.2 Hz and the SCF was approx. 0.1 Hz. The electrical signal in maize leaves was mainly a slow wave signal with a frequency of 0-0.1 Hz. After 2 h osmotic stress, the SEF and SCF of the electrical signal increased to higher frequencies. The proportion of the fast wave frequency also increased to 0.1-0.2 Hz, resulting in a dramatic increase in PSE. We also found that the changes in PSE and SCF were significantly correlated during osmotic stress. We propose that the changes in the PSE and SCF in maize leaves can be used as a sensitive signal indicat- ing water deficit in leaf cells under osmotic stress. Thus, measurement of SCF or PSE of electrical signals in maize leaves could be used to develop early warning and rapid diagnosis techniques for the water demands of plants.

关 键 词：植物电信号 玉米叶片 渗透胁迫 功率谱 中心频率 诱导 SCF PSE 

分 类 号：TN911.6[电子电信—通信与信息系统] S625.1[电子电信—信息与通信工程]