Department of Ecophysiology, Institute of Cellular and Molecular Botany, University of Bonn, Bonn, 53115, Germany.
Plant Breeding, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Munich, 85354, Germany.
Plant Cell Environ. 2020 Feb;43(2):344-357. doi: 10.1111/pce.13675. Epub 2019 Nov 24.
Wild barley, Hordeum vulgare spp. spontaneum, has a wider genetic diversity than its cultivated progeny, Hordeum vulgare spp. vulgare. Osmotic stress leads to a series of different responses in wild barley seminal roots, ranging from no changes in suberization to enhanced endodermal suberization of certain zones and the formation of a suberized exodermis, which was not observed in the modern cultivars studied so far. Further, as a response to osmotic stress, the hydraulic conductivity of roots was not affected in wild barley, but it was 2.5-fold reduced in cultivated barley. In both subspecies, osmotic adjustment by increasing proline concentration and decreasing osmotic potential in roots was observed. RNA-sequencing indicated that the regulation of suberin biosynthesis and water transport via aquaporins were different between wild and cultivated barley. These results indicate that wild barley uses different strategies to cope with osmotic stress compared with cultivated barley. Thus, it seems that wild barley is better adapted to cope with osmotic stress by maintaining a significantly higher hydraulic conductivity of roots during water deficit.
野生大麦（Hordeum vulgare spp. spontaneum）具有比其栽培后代（Hordeum vulgare spp. vulgare）更广泛的遗传多样性。渗透胁迫会导致野生大麦种胚根产生一系列不同的反应，从没有木质化的变化到特定区域的内皮层木质化增强和形成木质化的外表皮，而在迄今为止研究的现代品种中则没有观察到这种现象。此外，作为对渗透胁迫的响应，野生大麦的根的水力传导率不受影响，但在栽培大麦中则降低了 2.5 倍。在这两个亚种中，均观察到通过增加脯氨酸浓度和降低根中渗透压来进行渗透调节。RNA 测序表明，野生和栽培大麦之间存在通过水通道蛋白调节角质层生物合成和水分运输的不同机制。这些结果表明，与栽培大麦相比，野生大麦在应对渗透胁迫时采用了不同的策略。因此，野生大麦似乎通过在水分亏缺期间保持根的水力传导率显著提高来更好地适应渗透胁迫。
