National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Plant Biotechnol J. 2013 Dec;11(9):1080-91. doi: 10.1111/pbi.12102. Epub 2013 Aug 9.
Grain size, number and starch content are important determinants of grain yield and quality. One of the most important biological processes that determine these components is the carbon partitioning during the early grain filling, which requires the function of cell wall invertase. Here, we showed the constitutive expression of cell wall invertase-encoding gene from Arabidopsis, rice (Oryza sativa) or maize (Zea mays), driven by the cauliflower mosaic virus (CaMV) 35S promoter, all increased cell wall invertase activities in different tissues and organs, including leaves and developing seeds, and substantially improved grain yield up to 145.3% in transgenic maize plants as compared to the wild-type plants, an effect that was reproduced in our 2-year field trials at different locations. The dramatically increased grain yield is due to the enlarged ears with both enhanced grain size and grain number. Constitutive expression of the invertase-encoding gene also increased total starch content up to 20% in the transgenic kernels. Our results suggest that cell wall invertase gene can be genetically engineered to improve both grain yield and grain quality in crop plants.
粒大小、数量和淀粉含量是决定谷物产量和品质的重要因素。决定这些成分的最重要的生物学过程之一是早期灌浆过程中的碳分配，这需要细胞壁转化酶的功能。在这里，我们展示了由 CaMV 35S 启动子驱动的来自拟南芥、水稻或玉米的细胞壁转化酶编码基因的组成型表达，都增加了不同组织和器官（包括叶片和发育中的种子）中的细胞壁转化酶活性，并在转基因玉米植株中显著提高了 145.3%的产量，与野生型植株相比，这一效果在我们在不同地点的 2 年田间试验中得到了重现。产量的显著提高是由于穗部变大，粒大小和粒数都增加了。转化酶编码基因的组成型表达也使转基因核仁中的总淀粉含量增加了 20%。我们的结果表明，可通过遗传工程改造细胞壁转化酶基因来提高作物的产量和品质。
