Comparative effects of neutral salt and alkaline salt stress on seed germination, early seedling growth and physiological response of a halophyte species Chenopodium glaucum.
Comparative effects of neutral salt and alkaline salt stress on seed germination, early seedling growth and physiological response of a halophyte species Chenopodium glaucum.
复制标题
DOI：
10.5897/ajb12.320
复制
发表时间：
2012-01-01
影响因子：
--
通讯作者：
Lan, H. Y.
中科院分区：
文献类型：
--
作者：
Chen ShaSha, Chen ShaSha;Xing JiaJia, Xing JiaJia;Lan, H. Y.
研究了中性盐（NaCl）和碱性盐（NaHCO 3）胁迫对灰绿藜（Chenopodium glaucum）种子萌发、幼苗早期生长及15 d幼苗生理响应的影响。结果表明，较高浓度（≥ 300 mM）的NaCl胁迫严重抑制和延缓了苦豆子种子的萌发;而NaHCO_3胁迫对胚根和下胚轴伸长的抑制作用在较低浓度下也大于NaCl胁迫。相对含水量（RWC）。即使在最高的盐或碱胁迫下，glaucum仍然保持高水平。在低浓度NaCl和NaHCO 3胁迫下，渗透调节物质（脯氨酸、可溶性糖、甜菜碱）含量没有明显增加。Na+含量和Na+/K+比值在两种胁迫下均呈上升趋势，而K+含量呈下降趋势，NaHCO 3胁迫下的变化幅度大于NaCl胁迫。此外，低浓度NaHCO 3处理的幼苗产生了较高水平的活性氧（ROS、O2-、H2 O2），同时抗氧化酶[超氧化物歧化酶（SOD）、过氧化物酶（POX）]活性和非酶抗氧化剂[类胡萝卜素（Car）、抗坏血酸（阿萨）]含量显著增加。结果表明，碱盐胁迫对苦豆子幼苗生长、离子平衡和抗氧化系统的破坏作用。中性盐胁迫下，灰绿病比中性盐胁迫下严重。不同的pH环境可能是造成二者差异的关键原因。
Effects of neutral salt (NaCl) and alkaline salt (NaHCO3) stress on seed germination, early seedling growth and physiological response of 15-day-old seedling of Chenopodium glaucum, a halophyte widely distributed in temperate saline areas of China, were determined. Results show that NaCl stress of higher concentration (≥300 mM) more seriously retarded and postponed seed germination of C. glaucum, however, the inhibitory effect of NaHCO3 stress on radicle and hypocotyl elongation was greater than NaCl stress even at lower concentration. Relative water content (RWC) of C. glaucum remained high even under the highest salt or alkali stress. No obvious increase of osmolytes (proline, soluble sugar, betaine) was detected under lower concentration of NaCl and NaHCO3 stress. The Na+ content and Na+/K+ ratio increased while the K+ content decreased under both stresses, the changing extents under NaHCO3 were greater than those under NaCl stress. Moreover, seedlings exposed to lower concentration of NaHCO3 generated higher levels of reactive oxygen species (ROS, O2-, H2O2), meanwhile significant increase of antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POX)] activity and non-enzymatic antioxidants [Carotenoids (Car), ascorbic acid (AsA)] content were detected in seedlings treated with lower concentration of NaHCO3. Results suggest that the destructive effects of alkaline salt stress on the growth, ion balance and anti-oxidant system of seedling of C. glaucum were more severe than those under neutral salt stress. Different pH circumstance might be the key reason for the distinctive difference between them.