花粉管通道法获得转外源puroindoline基因小麦

[目的]验证pinA和pinB对小麦籽粒质地的影响。[方法]将含有控制硬度的主效基因pinA和pinB的单子叶植物高效表达载体pUBPa和pUBPb，分别通过花粉管通道法将其转入小麦品种中优9507（pinB-Dlb）中。[结果]获得了转基因植株，PCR检测和基因组Southern杂交证实了外源基因在受体小麦基因组中的整合，水洗淀粉表面蛋白的定量分析表明外源基因的导入影响了friabilin表达。与非转基因对照相比，小麦籽粒质地发生变化。[结论]结果表明，PINA和PINB共同作用形成frlabilin，从而直接影响小麦籽粒质地的形成。     

协同抑制番茄ACO1对果实成熟及病程相关蛋白基因表达的影响

 【目的】探讨协同抑制番茄ACO1基因对果实成熟和病程相关蛋白基因表达、内源乙烯生物合成及果实耐贮性的影响。【方法】采用PCR或RT-PCR方法克隆了番茄ACC氧化酶1、ACC氧化酶3、EBF1、PR1、PR5以及NP24基因片段，并以此制备探针，以协同抑制ACO1的转基因番茄和野生型番茄为研究对象，进行Northern杂交，同时测定了伤害叶片和果实的乙烯释放量，并进行了果实贮藏试验等。【结果】Northern杂交结果表明，番茄ACO1基因表达被抑制后，与果实成熟相关基因LeACO3和LeEBF1，以及病程相关蛋白基因LePR1、LePR5 和LeNP24的表达量急剧降低。乙烯释放量测定试验和果实贮藏试验结果表明，协同抑制LeACO1番茄完整和受伤叶片以及完整果实内源乙烯释放量相对于野生型番茄大大减少，成熟果实贮藏时间延长。【结论】协同抑制番茄ACO1基因表达的同时，与果实成熟相关基因和病程相关蛋白基因的表达也不同程度地受到抑制，而且其内源乙烯生物合成减少，果实耐贮性增强。     

Co-suppression of <Emphasis Type="Italic">Si401</Emphasis>, a maize pollen specific <Emphasis Type="Italic">Zm401</Emphasis> homologous gene,results in aberrant anther development in foxtail millet

We previously reported that the maize pollen-specific gene Zm401 functions in anther development. In this study, a Zm401’s ortholog Si401 was amplified and cloned from foxtail millet (Setaria italica). Zm401 and Si401 are highly conserved with 99% of their coding sequences identical to each other. Southern blot and RT-PCR analysis reveal that Si401 has only one copy in the genome and is expressed exclusively in the panicle. Co-suppression of Si401 in foxtail millet results in multiple abnormalities during the late stages of anther development, including premature degeneration of the tapetum, pre-deposition of fibrous bands in endothecium cells, and aborted pollen grains. Our results demonstrate that Si401 plays an essential role in anther development in foxtail millet and might be useful for generation of male-sterile plants in cereal crops.     

Fruit yield and quality of strawberry plants transformed with a fruit specific strawberry pectate lyase gene

Two transgenic strawberry lines (Pel 1 and Pel 3) containing the open reading frame of a fruit specific strawberry pectate lyase gene (FaplC) under the control of the CaMV35S promoter have been obtained to evaluate the role of this gene on fruit softening. Ripen fruits from both lines showed a significant down-regulation of FaplC, being the percentage of silencing of 84 and 71% on Pel 1 and Pel 3, respectively. The agronomic behaviour of transgenic plants was evaluated during two consecutive years. Fruit set increased in the two transgenic lines when compared with control plants, although Pel 1 showed a significant reduction on fruit weight. Firmness of full ripen fruits from Pel lines was significantly higher than control fruits, while color and soluble solids were not affected. The increase of firmness in Pel lines was maintained when ripe fruits were stored for 3 days at 25 °C. Histological analysis of ripe fruits showed lower intercellular spaces and a higher degree of cell to cell contact area in transgenic fruits when compared with controls. Altogether, these results suggest a direct relationship between pectate lyase gene expression and strawberry fruit softening.