水分亏缺条件下玉米根系TIP1-1基因的表达

以一组具有不同抗旱性状的玉米遗传材料杂交种户单4号(抗旱)及其父本803（不抗旱），母本天四（抗旱）为供试材料，以微管蛋白基因为内参基因，水通道蛋白基因TIP1-1为检测基因，在PEG-6000模拟水分亏缺条件下，采用半定量逆转录聚合酶链式反应（RT-PCR）体系检测TIP1-1基因在玉米根系中的表达情况。在正常

Expression of TIP1-1 in Maize Root Systems under Water Deficit

According to the `composite transport' model,parallel apoplastic,symplastic and trans-cellular pathways play an impostant role during the transport of water across different tissues.The role of water channels(aquaporins) in the trans-cellular path is in the fine adjustment of water flow or in the regulation of uptake in older,suberized parts of plant roots lacking a substantial apoplastic component.Many aquaporins are involved in regulating water transport in plants by adjusting their density and activity on the protoplasm membranes.To detect the expression of TIP1-1,a water channel protein gene,in maize root systems under water deficit,semi-quantitative PCR was used.The reference gene was tubulin.Maize seedlings of different genotypes with different drought resistances were cultured by hydroponics in growth chamber,for example,the filial generation Hudan 4 and the mother Tiansi both had great resistance to drought,but the father 803 had weak resistance to drought,furthermore,the filial generation Hudan 4 had the greatest drought resistance than the others.In our experiment,PEG-6000 was used to produce water deficit.According to figure 6,the results showed that the expression products of TIP1-1 was rich in the root systems of Tiansi and Hudan 4,but less in 803 than in Tiansi and Hudan 4 under normal water conditions.The expression of TIP1-1 was up-regulated in 803 but notenhanced in Tiansi and Hudan 4 under water deficit.Besides,Hudan 4 had the richest mRNA of TIP1-1 than the others under the two different water conditions.The results demonstrated that the amount of the expression products of water channel protein is related to water uptake by roots and drought resistance of plants,which is of great importance to maintain water homeostasis of the whole plant under water deficit.