Arena C, De Micco V, De Maio A
Department of Biology, University of Naples Federico II, Naples, Italy.
Plant Biol (Stuttg). 2014 Jan;16 Suppl 1:194-202. doi: 10.1111/plb.12076. Epub 2013 Aug 14.
Ionising radiation may have different effects on plant metabolism, growth and reproduction, depending on radiation dose, plant species, developmental stage and physiological traits. In this study, exposure of dwarf bean plants to different doses of X-rays (0.3, 10, 50, 100 Gy) was investigated with a multidisciplinary approach consisting of morphological, ecophysiological and biochemical analysis. Both mature and young leaves still growing during the X-rays exposure were compared with non-irradiated control leaves. In particular, leaf expansion, leaf anatomy and functional traits, as well as photosynthetic pigment content and Rubisco expression were analysed. Moreover, the activity of poly(ADP-ribose) polymerase (PARP) was also measured as an indicator of radiation-induced DNA damage. Our data showed that leaf growth is affected by high levels of radiation and demonstrate that mature leaves are more radio-resistant than young leaves, which experience severe dose-dependent changes in leaf functional traits. In particular, young leaves exhibited a reduction of area and an increase in specific mass and dry matter content, as well as a decline in Rubisco activity. Moreover, they showed elevated PARP activity and an increase in phenolic compounds in wall cells if compared with mature leaves. Both of these strategies have been interpreted as a way to help developing leaves withstand irradiation.
电离辐射可能对植物的新陈代谢、生长和繁殖产生不同影响，这取决于辐射剂量、植物种类、发育阶段和生理特性。在本研究中，采用形态学、生态生理学和生化分析的多学科方法，研究了矮生菜豆植株暴露于不同剂量X射线（0.3、10、50、100戈瑞）下的情况。将X射线照射期间仍在生长的成熟叶和幼叶与未照射的对照叶进行比较。特别分析了叶片扩展、叶片解剖结构和功能性状，以及光合色素含量和核酮糖-1,5-二磷酸羧化酶（Rubisco）的表达。此外，还测量了聚（ADP-核糖）聚合酶（PARP）的活性，作为辐射诱导DNA损伤的指标。我们的数据表明，高水平辐射会影响叶片生长，并证明成熟叶比幼叶更耐辐射，幼叶的叶片功能性状会经历严重的剂量依赖性变化。特别是，幼叶面积减小，比质量和干物质含量增加，Rubisco活性下降。此外，与成熟叶相比，它们的PARP活性升高，壁细胞中的酚类化合物增加。这两种策略都被解释为帮助发育中的叶片抵御辐射的一种方式。
