Inafuku Masashi, Basyuni Mohammad, Oku Hirosuke
Department of Applied Biological Information, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan.
Department of Forestry, Faculty of Forestry, University of Sumatera Utara, Medan, Indonesia.
Saudi J Biol Sci. 2018 Jan;25(1):1-9. doi: 10.1016/j.sjbs.2016.10.009. Epub 2016 Oct 20.
This study examined the effect of triterpenoid on the salt tolerance of lanosterol synthase deficient yeast mutant GIL77. The expression of the triterpenoid synthase gene under promoter in GIL77 increased the triterpenoid concentration of both whole cell and plasma membrane fractions. Without the induction of the genes, the growth curve of or transformant depicted patterns similar to control cells in both the presence and absence of salt with growth inhibition at 500 mM NaCl. The induction of and gene expression slightly repressed growth compared with control cells in the absence of NaCl. The growth of GIL77 was significantly suppressed by the expression of or under salinity conditions. Of the triterpenoid synthase genes, rather than was found to strongly inhibit the growth of GIL77 cells under salt stressed conditions. The expression of the triterpenoid synthase gene in GIL77 also influenced their tolerance to other abiotic stresses. In contrast to the endogenous synthesis, the exogenous supply of triterpenoid in the culture medium appeared to occur in the plasma membrane fraction and enhanced the salt tolerance of GIL77. This study thus discussed the physiological significance of triterpenoid in relation to its possible role in modulating salt tolerance.
本研究考察了三萜类化合物对羊毛甾醇合酶缺陷型酵母突变体GIL77耐盐性的影响。在启动子作用下，GIL77中三萜类合酶基因的表达增加了全细胞和质膜组分中的三萜类化合物浓度。在未诱导这些基因的情况下，无论是在有盐还是无盐条件下，或转化体的生长曲线与对照细胞相似，在500 mM NaCl时生长受到抑制。在无NaCl的情况下，与对照细胞相比，和基因表达的诱导略微抑制了生长。在盐度条件下，或的表达显著抑制了GIL77的生长。在三萜类合酶基因中，发现而非在盐胁迫条件下强烈抑制GIL77细胞的生长。GIL77中三萜类合酶基因的表达也影响了它们对其他非生物胁迫的耐受性。与内源性合成相反，培养基中外源供应的三萜类化合物似乎存在于质膜组分中，并增强了GIL77的耐盐性。因此，本研究讨论了三萜类化合物在调节耐盐性方面可能作用的生理意义。
