A possible origin of the middle phase of polyphasic chlorophyll fluorescence transient.
A possible origin of the middle phase of polyphasic chlorophyll fluorescence transient.
复制标题
多相叶绿素荧光瞬变的中间相的可能起源。
DOI：
10.1071/fp03012
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
K. Leu
中科院分区：
文献类型：
--
作者：
B. Hsu;K. Leu
高强度光化光诱导的全叶叶绿素荧光的上升包括三个不同的阶段，并被称为O-J-I-P多相上升。初始上升（O-J相）被认为是最敏感的光强度，是缓慢和较小的减少照射。还发现叶片在相当大的程度上对于叶绿素荧光是透明的，使得仍然可以检测到源自样品内部深处的荧光。相反，光化光诱导的荧光被叶绿素强烈吸收，导致光路上沿着产生一个陡峭的光梯度，叶片的荧光瞬变总是来自样品表面和样品内部的荧光的混合物，其O-J相的速度较慢，因为它是由较弱的光化光诱导的。我们提供的证据表明，在一个完整的叶片，测量的多相荧光瞬变（J-I相）的中间阶段可能实际上反映了最初的上升来自叶的远轴层的瞬态。此外，如果多相荧光瞬态被用作分析工具，用于访问叶片的光合活性的信息，样品的浓度和厚度的因素必须考虑。为了获得样品的“真实”荧光瞬变，样品的叶绿素浓度和厚度都必须保持尽可能低。
The rise of the chlorophyll fluorescence of a whole leaf as induced by high-intensity actinic light comprises three distinct phases, and is termed the O-J-I-P polyphasic rise. The initial rise (the O-J phase) was found to be the most sensitive to light intensity, being slower and smaller with decreasing irradiation. The leaf was also found to be transparent for chlorophyll fluorescence to a considerable extent, so that the fluorescence originating from deep inside the sample could still be detected. In contrast, the actinic light used to induce fluorescence was strongly absorbed by chlorophylls, so that a steep light gradient was created along the light path. The fluorescence transient of a leaf, thus, was always a mixture of the fluorescence from the surface of the sample as well as that from the inside of the sample, whose O-J phase is slower as it is induced by a weaker actinic light. We have provided evidence suggesting that, in an intact leaf, the middle phase of the measured polyphasic fluorescence transient (the J-I phase) might actually reflect the initial rise of the transient coming from the abaxial layer of the leaf. Moreover, if the polyphasic fluorescence transient is used as an analytical tool for accessing information on the photosynthetic activities of leaves, the factors of concentration and thickness of the sample must be taken into account. To obtain the 'true' fluorescence transient of a sample, both the chlorophyll concentration and thickness of the sample must be kept as low as possible.