During the Green Revolution in the 1960s, breeding dwarf cultivars turned out to be a landmark, leading to a significant increase in the global production of wheat and rice. The most direct and effective strategy for breeding dwarf crops, among others, would be to control endogenous gibberellin (GA) levels of the crops. GA 2-oxidases are a group of 2-oxoglutarate-dependent dioxygenases that catalyze the deactivation of bioactive GAs. The ArabidopsisAtGA2ox1 gene was transformed into maize with the aim of obtaining a height-reduced GM maize. The characterization of the GM maize revealed that the highest plant height reduction was accomplished by a 74% decline in GA1 level, and by approximately twofold increases in both chlorophyll content and root/shoot ratio over the wild-type (WT). Interestingly, the stem cells of the GM maize were condensed, and the typical vascular bundle structure was found to be deformed. Based on a 2-season field trial, the GM maize exhibited a higher harvest index (9-17%) and grain yield (10-14%) than the WT. The current results suggest that a modulation of the endogenous GA level would be a sensible approach for improving the crop architecture and grain yield in maize.

中文翻译：

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通过钝化具有生物活性的赤霉素，开发出矮生鱼和高产高效的转基因玉米。

在1960年代的“绿色革命”期间，矮化育种品种成为一个里程碑，导致全球小麦和大米产量大幅增加。矮人作物育种的最直接，最有效的策略是控制作物的内源赤霉素（GA）水平。GA 2-氧化酶是一组2-氧戊二酸依赖性双加氧酶，可催化生物活性GA的失活。为了获得高度降低的转基因玉米，将拟南芥AtGA2ox1基因转化为玉米。转基因玉米的特性表明，最高的株高降低是通过GA1含量下降74％，叶绿素含量和根/茎比均比野生型（WT）增长约两倍来实现的。有趣的是，转基因玉米的干细胞被浓缩，并且发现典型的血管束结构变形。根据为期2季的田间试验，转基因玉米的收割指数（9-17％）和谷物产量（10-14％）比野生玉米高。目前的结果表明，调节内源GA水平将是改善玉米的作物结构和谷物产量的明智方法。