Nigmatullina L R, Rumiantseva N I, Kostiukova Iu A
Ontogenez. 2014 Jan-Feb;45(1):50-62.
We studied the intracellular content of reduced (GSH) and oxidized (GSSG) glutathione, glutathione reductase activity, glutathione-S-transferase, and ascorbate peroxidase in morphogenic and nonmorphogenic Tatar buckwheat calli during the culture cycle as well as under the treatment with D,L-buthionine-S,R-sulfoximine (BSO), an inhibitor of γ-glutamylcysteine synthase, the first enzyme of glutathione biosynthesis. We found that, during passaging, cultures only slightly differed in total glutathione content; however, the content of GSH was higher in the morphogenic culture, whereas the content of GSSG was higher in the nonmorphogenic culture. In the morphogenic callus, the glutathione-S-transferase activity was 10-20 times higher and the glutathione reductase activity, was 2-2.5 times lower than in the nonmorphogenic callus. Under the treatment with BSO, the decrease in the GSH content in the morphogenic callus was temporary (on day 6-8 of passage), whereas that in the nonmorphogenic callus decreased within a day and remained lower than in the control throughout the entire passage. In the morphogenic callus, BSO did not affect the content of GSSG, whereas it caused GSSG accumulation in the nonmorphogenic callus. These differences are probably due to the fact that, in the BSO-containing medium, glutathione reductase is activated in the morphogenic callus and, conversely, inhibited in the nonmorphogenic callus. Although BSO caused a decrease in the total glutathione content only in the nonmorphogenic culture, the cytostatic effect of BSO was more pronounced in the morphogenic callus. In addition, BSO also had a negative effect on the differentiation ofproembryonic cell complexes in the morphogenic callus. The role of the glutathione redox status in maintaining the embryogenic activity of cultured plant cells is discussed.
我们研究了在培养周期中以及用γ-谷氨酰半胱氨酸合成酶（谷胱甘肽生物合成的第一种酶）的抑制剂D，L-丁硫氨酸-S，R-亚砜亚胺（BSO）处理后，形态发生型和非形态发生型苦荞麦愈伤组织中还原型（GSH）和氧化型（GSSG）谷胱甘肽的细胞内含量、谷胱甘肽还原酶活性、谷胱甘肽-S-转移酶和抗坏血酸过氧化物酶。我们发现，在继代培养过程中，不同培养物的总谷胱甘肽含量仅略有差异；然而，形态发生型培养物中GSH的含量较高，而非形态发生型培养物中GSSG的含量较高。在形态发生型愈伤组织中，谷胱甘肽-S-转移酶活性比非形态发生型愈伤组织高10 - 20倍，而谷胱甘肽还原酶活性则低2 - 2.5倍。在用BSO处理后，形态发生型愈伤组织中GSH含量的下降是暂时的（在继代培养的第6 - 8天），而非形态发生型愈伤组织中的GSH含量在一天内就下降了，并且在整个继代培养过程中一直低于对照。在形态发生型愈伤组织中，BSO不影响GSSG的含量，而在非形态发生型愈伤组织中却导致GSSG积累。这些差异可能是由于在含有BSO的培养基中，谷胱甘肽还原酶在形态发生型愈伤组织中被激活，而在非形态发生型愈伤组织中则被抑制。虽然BSO仅在非形态发生型培养物中导致总谷胱甘肽含量下降，但BSO的细胞抑制作用在形态发生型愈伤组织中更为明显。此外，BSO对形态发生型愈伤组织中前胚细胞复合体的分化也有负面影响。本文还讨论了谷胱甘肽氧化还原状态在维持培养植物细胞胚胎发生活性中的作用。
