Data from: Tissue culture as a source of replicates in non-model plants: variation in cold response in Arabidopsis lyrata ssp. petraea

Whilst genotype-environment interaction is increasingly receiving
attention by ecologists and evolutionary biologists, such studies need
genetically homogeneous replicates-a challenging hurdle in outcrossing
plants. This could potentially be overcome by using tissue culture
techniques. However, plants regenerated from tissue culture may show
aberrant phenotypes and "somaclonal" variation. Here we examined
the somaclonal variation due to tissue culturing using the response to
cold treatment of the photosynthetic efficiency (chlorophyll fluorescence
measurements for Fv/Fm, Fv'/Fm' and ΦPSII, representing maximum
efficiency of photosynthesis for dark- and light-adapted leaves, and the
actual electron transport operating efficiency, respectively, which are
reliable indicators of photoinhibition and damage to the photosynthetic
electron transport system). We compared this to variation among
half-sibling seedlings from three different families of Arabidopsis lyrata
ssp. petraea. Somaclonal variation was limited and we could successfully
detect within-family variation in change in chlorophyll fluorescence due
to cold shock with the help of tissue-culture derived replicates.
Icelandic and Norwegian families exhibited higher chlorophyll
fluorescence, suggesting higher performance after cold shock, than a
Swedish family. Although the main effect of tissue culture on Fv/Fm,
Fv'/Fm' and ΦPSII, was small, there were significant
interactions between tissue culture and family, suggesting that the effect
of tissue culture is genotype-specific. Tissue-cultured plantlets were
less affected by cold treatment than seedlings, but to a different extent
in each family. These interactive effects, however, were comparable to, or
much smaller than the single effect of family. These results suggest that
tissue culture is a useful method for obtaining genetically homogenous
replicates for studying genotype-environment interaction related to
adaptively-relevant phenotypes, such as cold response, in non-model
outcrossing plants.

尽管基因型-环境互作（genotype-environment interaction）正日益受到生态学家与进化生物学家的关注，但此类研究需要遗传均一的重复样本——这在异交植物中是一项极具挑战性的障碍。这一难题可通过组织培养技术得到潜在解决。不过，经由组织培养再生的植株可能会出现异常表型与‘体细胞无性系变异（somaclonal variation）’。本研究以光合效率对低温处理的响应为指标，考察了组织培养引发的体细胞无性系变异：光合效率通过叶绿素荧光测定参数Fv/Fm、Fv'/Fm'与ΦPSII体现，三者分别代表暗适应与光适应叶片的光合最大效率，以及实际电子传递运行效率，是光抑制与光合电子传递系统受损的可靠指示指标。我们将该变异与拟南芥 lyrata 亚种 petraea（Arabidopsis lyrata ssp. petraea）三个不同家系的半同胞子代幼苗间的变异进行了对比。研究发现体细胞无性系变异程度有限，且我们借助组织培养获得的重复样本，成功检测到了冷激引发的叶绿素荧光变化的家系内变异。相较于瑞典家系，冰岛与挪威家系的叶绿素荧光水平更高，表明其冷激后的光合表现更优。尽管组织培养对Fv/Fm、Fv'/Fm'与ΦPSII的主效应较小，但组织培养与家系间存在显著交互作用，表明组织培养的效应具有基因型特异性。组织培养的小苗相较于幼苗，受低温处理的影响更小，但该影响程度在不同家系间存在差异。不过，这些交互效应与家系的单一效应相比，量级相当甚至更小。本研究结果表明，对于非模式异交植物而言，组织培养是一种获取遗传均一重复样本的有效方法，可用于研究与适应性相关表型（如低温响应）相关的基因型-环境互作。