Fujiki Yuki, Yoshikawa Yoko, Sato Tokuyuki, Inada Noriko, Ito Masaki, Nishida Ikuo, Watanabe Akira
Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Physiol Plant. 2001 Mar;111(3):345-352. doi: 10.1034/j.1399-3054.2001.1110312.x.
We have isolated 5 cDNA clones (din2, din6, din9, din10 and din11) corresponding to genes, the transcripts of which accumulated in leaves of Arabidopsis thaliana kept in the dark. These cDNA clones encode proteins similar to beta-glucosidase (EC 3.2.1.21, din2), asparagine synthetase (EC 6.3.5.4, din6), phosphomannose isomerase (EC 5.3.1.8, din9), seed imbibition protein (din10) and 2-oxoacid-dependent dioxygenases (din11). Accumulation of the transcripts from din6 and din10 occurred within 3 h after plants were transferred to darkness. The transcripts from din2, din9 and din11 were only detected after 24 h of dark treatment. We also observed the accumulation of the din transcripts in senescing leaves. Application of a photosynthesis inhibitor, 3-(3,4-dichlorophenyl)-1-1-dimethyl-urea, induced the expression of the din genes under illumination. Application of sucrose to detached leaves suppressed the accumulation of the din transcripts in the dark. These results indicate that expression of these genes partly depends on cellular sugar level. The sugar-modulated expression of the din genes suggests that dark-induced expression of these genes might be related to sugar starvation occurring in leaf cells in the dark, when the photosynthesis is hindered.
我们分离出了5个与基因对应的cDNA克隆（din2、din6、din9、din10和din11），这些基因的转录本在黑暗中保存的拟南芥叶片中积累。这些cDNA克隆编码的蛋白质分别类似于β-葡萄糖苷酶（EC 3.2.1.21，din2）、天冬酰胺合成酶（EC 6.3.5.4，din6）、磷酸甘露糖异构酶（EC 5.3.1.8，din9）、种子吸涨蛋白（din10）和2-氧代酸依赖性双加氧酶（din11）。植物转移到黑暗中3小时内，din6和din10的转录本开始积累。黑暗处理24小时后才检测到din2、din9和din11的转录本。我们还观察到din转录本在衰老叶片中积累。施用光合作用抑制剂3-(3,4-二氯苯基)-1,1-二甲基脲可在光照条件下诱导din基因的表达。向离体叶片施用蔗糖可抑制黑暗中din转录本的积累。这些结果表明这些基因的表达部分取决于细胞内的糖水平。din基因的糖调节表达表明，这些基因在黑暗中的诱导表达可能与黑暗中光合作用受阻时叶细胞中发生的糖饥饿有关。
