Quantification of light screening by anthocyanins in leaves of Berberis thunbergii
Quantification of light screening by anthocyanins in leaves of Berberis thunbergii
复制标题
DOI：
10.1007/s00425-017-2752-2
复制
发表时间：
2017-08
期刊：
影响因子：
4.3
通讯作者：
Lars Nichelmann;W. Bilger
中科院分区：
文献类型：
--
作者：
Lars Nichelmann;W. Bilger
主要结论在体内，花色苷屏蔽了高达40%的入射光，导致光合作用降低40%。关于花色苷在叶片中的生物学功能，人们一直在讨论，但大多数作者支持这种屏蔽功能的假说。对于作为光保护色素的功能的评估，它们对叶肉的筛选的量化是重要的。本文利用红、绿两个品种的小檗叶绿素荧光激发，在545 nm处和整个光合作用有效波长范围内估计花色苷对其的遮挡程度。在强光(430mmol.m−2s−1)下生长可在545nm处产生90%的屏蔽，对应于整个波长范围内40%-50%的屏蔽，具体取决于光源。伴随而来的光合作用量子效率的减少与到达叶绿体的光的计算减少的大小相同。红色品种花青素的诱导也增强了紫黄质循环在生长条件下的环氧化状态，表明红叶受到过强光照的影响较小。紫黄质循环类胡萝卜素的池大小表明红叶中捕光复合体的遮荫适应。观察到的花青素叶片内部光的减少必然具有光保护作用。
Main conclusionUp to 40% of incident light was screened in redBerberisleaves in vivo by anthocyanins, resulting also in up to 40% reduction of light-limited photosynthesis.The biological function of anthocyanins in leaves has been strongly discussed, but the hypothesis of a screening function is favored by most authors. For an evaluation of the function as photoprotective pigments, a quantification of their screening of the mesophyll is important. Here, chlorophyll fluorescence excitation of leaves of a red and a green variety ofBerberis thunbergiiwas used to estimate the extent of screening by anthocyanins at 545 nm and over the whole photosynthetically active wavelength range. Growth at high light (430 µmol m−2s−1) resulted in 90% screening at 545 nm corresponding to 40–50% screening over the whole wavelength range, depending on the light source. The concomitant reduction of photosynthetic quantum yield was of the same size as the calculated reduction of light reaching the chloroplasts. The induction of anthocyanins in the red variety also enhanced the epoxidation state of the violaxanthin cycle under growth conditions, indicating that red leaves were suffering less from excessive irradiance. Pool sizes of violaxanthin cycle carotenoids indicated a shade acclimation of the light harvesting complexes in red leaves. The observed reduction of internal light in anthocyanic leaves has by necessity a photoprotective effect.