Wyka Tomasz, Robakowski Piotr, Zytkowiak Roma
Adam Mickiewicz University, Biology Department, Laboratory of General Botany, ul. Umultowska 89, 61-614 Poznañ, Poland.
Tree Physiol. 2007 Sep;27(9):1293-306. doi: 10.1093/treephys/27.9.1293.
Leaves developing in different irradiances undergo structural and functional acclimation, although the extent of trait plasticity is species specific. We tested the hypothesis that irradiance-induced plasticity of photosynthetic and anatomical traits is lower in highly shade-tolerant species than in moderately shade-tolerant species. Seedlings of two evergreen conifers, shade-tolerant Abies alba Mill. and moderately shade-tolerant Picea abies Karst., and two deciduous angiosperm species, highly shade-tolerant Fagus sylvatica L. and moderately shade-tolerant Acer pseudoplatanus L., were grown in deep shade (LL, 5% of full irradiance) or in full solar irradiance (HL) during 2003 and 2004. Steady state responses of quantum yield of PSII (Phi(PSII)), apparent electron transport rate (ETR), nonphotochemical quenching (NPQ) and photochemical quenching (qP) were generally modified by the light environment, with slower declines in Phi(PSII) and qP and greater maximal ETR and NPQ values in HL plants in at least one season; however, no link between quantitative measures of plasticity of these traits and shade tolerance was found. Plasticity of nine anatomical traits (including palisade cell length, which was reduced in LL) showed no relationship with shade tolerance, but was less in conifers than in deciduous trees, suggesting that leaf life span may be a significant correlate of plasticity. When LL-acclimated plants were exposed to HL conditions, the degree and duration of photoinhibition (measured as a decline in maximum quantum yield) was greatest in F. sylvatica, much lower in P. abies and A. alba, and lowest in A. pseudoplatanus. Thus, as with the other traits studied, vulnerability to photoinhibition showed no relationship with shade tolerance.
在不同光照强度下发育的叶片会经历结构和功能上的适应性变化，尽管性状可塑性的程度因物种而异。我们检验了这样一个假设：在高耐荫性物种中，光照诱导的光合和解剖性状可塑性低于中度耐荫性物种。2003年和2004年期间，将两种常绿针叶树（耐荫的欧洲冷杉和中度耐荫的欧洲云杉）以及两种落叶被子植物（高耐荫的欧洲山毛榉和中度耐荫的挪威槭）的幼苗种植在深度遮荫（LL，全光照的5%）或全光照（HL）条件下。PSII量子产率（Phi(PSII)）、表观电子传递速率（ETR）、非光化学猝灭（NPQ）和光化学猝灭（qP）的稳态响应通常会受到光照环境的影响，至少在一个季节中，HL植株的Phi(PSII)和qP下降较慢，最大ETR和NPQ值更大；然而，未发现这些性状可塑性的定量指标与耐荫性之间存在关联。九种解剖性状（包括栅栏细胞长度，在LL条件下缩短）的可塑性与耐荫性无关，但针叶树的可塑性低于落叶树，这表明叶片寿命可能是可塑性的一个重要相关因素。当LL适应的植株暴露于HL条件下时，光抑制的程度和持续时间（以最大量子产率的下降来衡量）在欧洲山毛榉中最大，在欧洲云杉和欧洲冷杉中低得多，在挪威槭中最低。因此，与其他研究的性状一样，对光抑制的敏感性与耐荫性无关。
