将水稻自身焦磷酸化酶基因OsIP1置于叶肉细胞特异表达启动子下，利用农杆菌介导法将嵌合基因cyFBPase:OsIP1分别导入“源限制型” 水稻品种中超123和“库限制型” 品种农垦57。 根据荧光定量PCR结果和农艺性状，筛选高表达且农艺性状没有明显改变的T2转基因纯合株系，用以检测和分析在水稻叶肉细胞中特异性过表达水稻焦磷酸化酶基因的效应。初步的研究结果显示：1）在营养生长期，转基因株系的最高茎蘖数和穗数比各受体亲本均有不同程度的提高，尤其是在分蘖性较强的品种上；2）在籽粒灌浆结实期，叶片、叶鞘中可溶性总糖、蔗糖和淀粉含量在整个灌浆期的变化趋势与对照相似，且多数转基因植株叶片和叶鞘中的蔗糖含量（除了灌浆高峰期时的叶鞘）均显著高于对照；3）转基因株系单株干物质量较野生型对照有显著提高。单株产量呈现不同程度的增加，其中“源限制型”品种中超123转基因株系单株产量较对照增幅达显著水平。
OsIP1, encoding soluble inorganic pyrophosphatase was cloned and inserted between the rice mesophyllspecific promoter “cyFBPase” and the poly(A) site of the octopine synthase gene, and transferred into different sourcesink type rice cultivars, including sourcelimiting type Zhongchao 123 and sinklimiting type Nongken57 by Agrobacteriummediated gene transfer. Some T0 transgenic plants with high expression level were selected by quantitative realtime PCR and their T2 homozygous lines with the same morphological and agronomic traits as their wildtype cultivar were generated. The effects of overexpressed OsIP1 specifically in the mesophyll cell were estimated by investigating tiller dynamics, soluble and stored carbohydrate contents in leaf blade and leaf sheath, and dry weight and yield and so on. The preliminary results showed that during the vegetative stage, the tilling capability and panicles per plant of transgenic lines increased to a certain extent, especially in the high tillering capability variety, Nongken 57. The results also showed that during the grainfilling stage, the changing trends of the soluble sugar, sucrose and starch contents in leaf blade and leaf sheath of transgenic lines were consistent with those of the wild types. Except leaf sheath at the peak grainfilling stage, the sucrose content of transgenic lines were increased significantly at each time point. Compared with the wild types, the dry weights and grain yields of transgenic lines increased to a varying degree. The grain yield of the transgenic lines of Zhongchao 123 were significantly higher than that of the wild type.
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