Zeliou K, Kyzeridou A, Petropoulou Y
Laboratory of Plant Physiology, Department of Biology, University of Patras, Patras GR-26504, Greece.
Photosynthetica. 2022 Jan 13;60(1):70-78. doi: 10.32615/ps.2021.062. eCollection 2022.
Foliar anthocyanins shape a peculiar shade in a red leaf's interior leading to uneven energy distribution between the two photosystems. Accordingly, a readjustment of PSII/PSI stoichiometry could restore excitation balance. To test this hypothesis, 77 K fluorescence emission spectra of thylakoids from green and red leaves of seven species with different pigment profiles were compared. The ratio of F/F served as an indication of the PSII/PSI functional ratio. To avoid possible species-dependent differences in the measured parameters, plants showing intra-individual, intra-species, or intra-leaf variation in the expression of the anthocyanic character were used. Red leaves or red leaf areas displayed higher PSII/PSI ratio, irrespectively of species and anthocyanin accumulation pattern. PSII/PSI ratio declined in parallel with anthocyanin decrease. In five species, red leaves displayed also a lower Chl / ratio. We conclude that red leaves growing in full sunlight develop adaptive adjustments in their chlorophyll and photosystem ratios, compatible with the shade-acclimation syndrome.
叶片花青素在红叶内部形成一种特殊的色调，导致两个光系统之间的能量分布不均。因此，调整PSII/PSI化学计量比可以恢复激发平衡。为了验证这一假设，比较了具有不同色素谱的七个物种的绿叶和红叶类囊体的77K荧光发射光谱。F/F比值作为PSII/PSI功能比的指标。为了避免测量参数中可能存在的物种依赖性差异，使用了在花青素特征表达上表现出个体内、物种内或叶内变异的植物。红叶或红叶区域显示出较高的PSII/PSI比值，与物种和花青素积累模式无关。PSII/PSI比值随着花青素的减少而平行下降。在五个物种中，红叶的Chl/比值也较低。我们得出结论，在充足阳光下生长的红叶在叶绿素和光系统比例上会进行适应性调整，这与阴生适应综合征相符。
