Assaha Dekoum Vincent Marius, Liu Liyun, Ueda Akihiro, Nagaoka Toshinori, Saneoka Hirofumi
J Environ Biol. 2016 Jan;37(1):107-14.
The present study sought to investigate the factors implicated in growth impairment of huckleberry (a leafy vegetable) under water stress conditions. To achieve this, seedlings of plant were subjected to control, mild stress and severe stress conditions for 30 days. Plant growth, plant water relation, gas exchange, oxidative stress damage, electrolyte leakage rate, mineral content and osmolyte accumulation were measured. Water deficit markedly decreased leaf, stem and root growth. Leaf photosynthetic rate was tremendously reduced by decrease in stomatal conductance under stress conditions. Malondialdehyde (MDA) content markedly increased under mild (82%) and severe (131%) stress conditions, while electrolyte leakage rate (ELR) increased by 59% under mild stress and 3-fold under severe stress. Mineral content in leafwas high in stressed plants, while proline content markedly increased under mild stress (12-fold) and severe stress (15-fold), with corresponding decrease in osmotic potential at full turgor and an increase in osmotic adjustment. These results suggest that maintenance of high mineral content and osmotic adjustment constitute important adaptations in huckleberry under water deficit conditions and that growth depression under drought stress would be mainly caused by increased electrolyte leakage resulting from membrane damage induced by oxidative stress.
本研究旨在探究水分胁迫条件下越橘（一种叶菜类蔬菜）生长受抑制的相关因素。为此，将植物幼苗置于对照、轻度胁迫和重度胁迫条件下处理30天。测定了植物生长、植物水分关系、气体交换、氧化应激损伤、电解质渗漏率、矿物质含量和渗透调节物质积累。水分亏缺显著降低了叶片、茎和根的生长。胁迫条件下气孔导度降低，导致叶片光合速率大幅下降。轻度（82%）和重度（131%）胁迫条件下丙二醛（MDA）含量显著增加，轻度胁迫下电解质渗漏率（ELR）增加59%，重度胁迫下增加3倍。胁迫植株叶片中的矿物质含量较高，而脯氨酸含量在轻度胁迫（增加12倍）和重度胁迫（增加15倍）下显著增加，同时在完全膨压下渗透势相应降低，渗透调节增加。这些结果表明，在水分亏缺条件下，维持高矿物质含量和渗透调节是越橘的重要适应性机制，干旱胁迫下生长受抑制主要是由于氧化应激诱导膜损伤导致电解质渗漏增加所致。
