A rice semi-dwarf gene, Tan-Ginbozu (D35), encodes the gibberellin biosynthesis enzyme, ent-kaurene oxidase
A rice semi-dwarf gene, Tan-Ginbozu (D35), encodes the gibberellin biosynthesis enzyme, ent-kaurene oxidase
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DOI：
10.1023/b:plan.0000038261.21060.47
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发表时间：
2004-03-01
影响因子：
5.1
通讯作者：
Matsuoka, M
中科院分区：
文献类型：
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作者：
Itoh, H;Tatsumi, T;Matsuoka, M
稻（Oryza sativa L.）半矮秆品种Tan-Ginbozu （d35(Tan-Ginbozu)）在20世纪50年代对日本作物生产力的提高做出了贡献。先前的研究认为，d35（Tan-Ginbozu）的半矮化身材是由赤霉素生物合成的早期阶段缺陷引起的，该阶段是由entkaurene氧化酶（KO）催化的。为了研究d35（tanginbozu）的分子特征，我们从水稻基因组中分离出5个KO-like （KOL）基因，这些基因编码的蛋白质与拟南芥和南瓜的KOs高度同源。基因（OsKOL1 ~ 5）在120 kb的序列中沿同一方向串联重复序列排列。表达分析显示，OsKOL2和OsKOL4在各器官中均有活性转录，而OsKOL1和OsKOL5仅低水平表达；OsKOL3可能是一个假基因。序列分析和互补实验表明OsKOL2与D35对应。与D35零等位基因的纯合子表现为严重的矮化表型；因此，d35（Tan-Ginbozu）是d35的弱等位基因。将OsKOL4导入d35（Tan-Ginbozu）后，其矮化表型并未恢复，表明OsKOL4不参与GA的生物合成。OsKOL4和OsKOL5可能参与植物抗菌素的生物合成，因为它们的表达在紫外线照射和/或激发剂处理下被促进。通过对d35（TanGinbozu）与其他高产品种的比较，探讨了通过降低GA水平来构建适合作物高产的茎秆结构的策略。
A rice (Oryza sativa L.) semi-dwarf cultivar, Tan-Ginbozu (d35(Tan-Ginbozu)), contributed to the increase in crop productivity in Japan in the 1950s. Previous studies suggested that the semi-dwarf stature of d35(Tan-Ginbozu) is caused by a defective early step of gibberellin biosynthesis, which is catalyzed by entkaurene oxidase (KO). To study the molecular characteristics of d35(Tan-Ginbozu), we isolated 5 KO-like (KOL) genes from the rice genome, which encoded proteins highly homologous to Arabidopsis and pumpkin KOs. The genes (OsKOL1 to 5) were arranged as tandem repeats in the same direction within a 120 kb sequence. Expression analysis revealed that OsKOL2 and OsKOL4 were actively transcribed in various organs, while OsKOL1 and OsKOL5 were expressed only at low levels; OsKOL3 may be a pseudogene. Sequence analysis and complementation experiments demonstrated that OsKOL2 corresponds to D35. Homozygote with null alleles of D35 showed a severe dwarf phenotype; therefore, d35(Tan-Ginbozu) is a weak allele of D35. Introduction of OsKOL4 into d35(Tan-Ginbozu) did not rescue its dwarf phenotype, indicating that OsKOL4 is not involved in GA biosynthesis. OsKOL4 and OsKOL5 are likely to take part in phytoalexin biosynthesis, because their expression was promoted by UV irradiation and/or elicitor treatment. Comparing d35(TanGinbozu) with other high yielding cultivars, we discuss strategies to produce culm architectures suitable for high crop yield by decreasing GA levels.