Recent climatic changes have resulted in an increased frequency and prolonged periods of drought and strained water resources affecting plant production. We explored the possibility of reducing irrigation in a container nursery and studied the growth responses of seedlings of four economically important forest trees: broadleaf deciduous angiosperms Fagus sylvatica, Quercus petraea, and evergreen conifers Abies alba and Pinus sylvestris. We also studied markers of water stress including modifications of biomass allocation, leaf anatomy, proline accumulation, and expression of selected genes. Growth of the broadleaved deciduous species was more sensitive to the reduced water supply than that of conifers. Remarkably, growth of the shade tolerant Abies was not affected. Adjustment of biomass allocations was strongest in P. sylvestris, with a remarkable increase in allocation to roots. In response to water deficit both deciduous species accumulated proline in leaves and produced leaves with shorter palisade cells, reduced vascular tissues, and smaller conduit diameters. These responses did not occur in conifers. Relative transcript abundance of a gene encoding the Zn-finger protein in Q. petraea and a gene encoding the pore calcium channel protein 1 in A. alba increased as water deficit increased. Our study shows major differences between functional groups in response to irrigation, with seedlings of evergreen conifers having higher tolerance than the deciduous species. This suggests that major water savings could be achieved by adjusting irrigation regime to functional group or species requirements.

中文翻译：

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集装箱苗圃常绿针叶树和阔叶落叶林树种不同表型和分子响应对缺水调节的实际意义

最近的气候变化导致干旱和水资源紧张的频率增加并延长了时间，影响了植物的生产。我们探索了减少集装箱苗圃灌溉的可能性，并研究了四种经济上重要的林木的幼苗的生长响应：阔叶落叶被子植物Fagus sylvatica，Quercus petraea和常绿针叶树Abies alba和Pinus sylvestris。我们还研究了水分胁迫的标志物，包括生物量分配，叶片解剖，脯氨酸积累和所选基因表达的修饰。与针叶树相比，阔叶落叶树种的生长对水供应的减少更为敏感。显着地，耐荫冷杉的生长没有受到影响。樟子松对生物量分配的调节最强，对根的分配显着增加。响应缺水，两种落叶物种都在叶片中积累脯氨酸，并产生具有较短栅栏细胞，减少的维管组织和较小导管直径的叶片。这些反应在针叶树中没有发生。Q中编码锌指蛋白的基因的相对转录丰度。佩特拉行省和在编码所述孔的钙通道蛋白1的基因甲。随着水分亏缺的增加，白菜也增加。我们的研究表明，不同类别之间在灌溉方面的差异很大，常绿针叶树的幼苗比落叶树的耐受性更高。这表明可以通过根据功能组或物种要求调整灌溉制度来实现节水。