Agronomy College, Chengdu Campus, Sichuan Agricultural University , Wenjiang 611130, China.
J Agric Food Chem. 2013 Jun 19;61(24):5720-6. doi: 10.1021/jf401237x. Epub 2013 Jun 5.
This study examined the effects of three different NaCl concentrations (60, 90, and 120 mM) on the growth, physiological responses, and steviol glycoside composition of Stevia rebaudiana Bertoni for 4 weeks. The results showed that the total dry weight decreased by 40% at 120 mM NaCl but remained the same at 60 and 90 mM NaCl. As salt concentration increased, chlorophyll contents decreased markedly by 10-70%, whereas the increments of the antioxidant enzyme activities were 1.0-1.6, 1.2-1.3, and 2.0-4.0 times, respectively, for superoxide dismutase, peroxidase, and catalase. The proline contents in salt-treated plants were 17-42 times higher than that in control. Moreover, leaf possessed significantly higher K⁺ content and K⁺/Na⁺ ratio than stem and root for all salt treatments. In addition, 90-120 mM NaCl treatment notably decreased the content of rebaudioside A (RA) and stevioside (ST) by 16.2-38.2%, whereas the increment of the ratio of RA/ST of salt-treated plants was 1.1-1.4 times. These results indicate that S. rebaudiana is moderately tolerant to salt stress. Hypohaline soil can be utilized in the plantation of S. rebaudiana and may be profitable for optimizing the steviol glycoside composition.
本研究考察了 3 种不同 NaCl 浓度（60、90 和 120mM）对甜菊叶 4 周生长、生理响应和甜菊糖苷组成的影响。结果表明，120mM NaCl 下总干重下降了 40%，而 60 和 90mM NaCl 下总干重保持不变。随着盐浓度的增加，叶绿素含量显著下降了 10-70%，而抗氧化酶活性分别增加了 1.0-1.6、1.2-1.3 和 2.0-4.0 倍，超氧化物歧化酶、过氧化物酶和过氧化氢酶。盐处理植物中的脯氨酸含量比对照高 17-42 倍。此外，叶片中 K⁺含量和 K⁺/Na⁺比值均显著高于茎和根，所有盐处理均如此。此外，90-120mM NaCl 处理显著降低了瑞鲍迪苷 A（RA）和甜菊苷（ST）的含量，分别下降了 16.2-38.2%，而盐处理植物中 RA/ST 的比值增加了 1.1-1.4 倍。这些结果表明，甜菊对盐胁迫具有中度耐受性。低盐土壤可用于甜菊的种植，可能有利于优化甜菊糖苷的组成。
