Kov Daniel, Navr Til Martin, Malenovsk Zbyn K, Troch Michal, Punda Vladim R, Urban Otmar
Global Change Research Centre AS CR, v.v.i., Bělidla 4a, CZ-60300 Brno, Czech Republic.
Department of Physics, Faculty of Science, University of Ostrava, Chittussiho 10, CZ-71000 Slezská Ostrava, Czech Republic.
Funct Plant Biol. 2012 Dec;39(12):987-998. doi: 10.1071/FP12107.
This laboratory experiment tested the ability of the spectral index called 'area under curve normalised to maximal band depth' (ANMB) to track dynamic changes in the xanthophyll cycle of Norway spruce (Picea abies (L.) Karsten) needles. Four-year-old spruce seedlings were gradually acclimated to different photosynthetic photon flux densities (PPFDs) and air temperature regimes. The measurements were conducted at the end of each acclimation period lasting for 11 days. A significant decline in the chlorophylls to carotenoids ratio and the increase of the amount of xanthophyll cycle pigments indicated a higher need for carotenoid-mediated photoprotection in spruce leaves acclimated to high PPFD conditions. Similarly, the photochemical reflectance index (PRI) changed from positive to negative values after changing light conditions from low to high intensity as a consequence of the increase in carotenoid content. Systematic responses of PRI to the de-epoxidation state of xanthophyll cycle pigments (DEPS) were, however, observed only during high temperature treatments and after the exposition of needles to high irradiance. The ANMB index computed from needle reflectance between 507 and 556nm was able to track dynamic changes in DEPS without any influence induced by changing the content of leaf photosynthetic pigments (chlorophylls, carotenoids).
本实验室实验测试了名为“归一化到最大波段深度的曲线下面积”（ANMB）的光谱指数跟踪挪威云杉（Picea abies (L.) Karsten）针叶叶黄素循环动态变化的能力。对四年生云杉幼苗逐步进行驯化，使其适应不同的光合光子通量密度（PPFD）和气温条件。在每个持续11天的驯化期结束时进行测量。叶绿素与类胡萝卜素比值显著下降以及叶黄素循环色素含量增加，表明适应高PPFD条件的云杉叶片对类胡萝卜素介导的光保护有更高需求。同样，由于类胡萝卜素含量增加，在光照条件从低强度变为高强度后，光化学反射指数（PRI）从正值变为负值。然而，仅在高温处理期间以及针叶暴露于高辐照后，观察到PRI对叶黄素循环色素脱环氧化状态（DEPS）的系统性响应。根据507至556nm之间的针叶反射率计算出的ANMB指数能够跟踪DEPS的动态变化，而不受叶片光合色素（叶绿素、类胡萝卜素）含量变化的任何影响。
