中文摘要：

尽管广泛的研究证明了许多干旱应答的基因授与干旱忍耐到植物，能力在各种各样的自然条件下面由不同基因授与的干旱忍耐的比较很少有报导。我们评估了并且比较 transgenes，干旱应答的基因(AtDREB1B 和 AtCBL1 ) 和根的二个集合的效果调整建筑学的基因(iaaM 和 AtCKX ) ，在在 Nicotiana tabacum 的干旱忍耐上，植物使遭到了到不同条件。根特定的倡导者 PYK10 驾驶的 AtCKX3 的表示(此后指定了为 P10；P10 : AtCKX3 ) ， 35S:AtCKX3，或 P10:iaaM 支持了根生长和开发。比作怀有 P10 的植物: 展出的 AtCKX3， 35S:AtCKX3， P10:iaaM，或空向量，那些带的 35S:AtDREB1B， 35S:AtCBL1，或 35S:iaaM 在控制实验室的条件下面增加了干旱忍耐。相反地，在地里，条件，与 35S:AtDREB1 转变的植物， 35S:AtCBL1，或 35S:iaaM 对干旱应力敏感。在地条件下面，干旱应力戏剧性地减少了生长和而它在带 P10 的植物上有小效果，怀有 35S:AtDREB1B， 35S:AtCBL1， 35S:iaaM，或空向量的植物的种子生产: AtCKX3， 35S:AtCKX3，或 P10:iaaM。这研究证明到有环境条件的干旱压力变化的植物忍耐，和我们的结果显示操作控制根建筑学的基因的表示可能为处于自然条件与改进干旱忍耐设计植物是重要的。

英文摘要：

Although extensive studies have demonstrated that many drought-responsive genes confer drought toler- ance to plants, comparisons of the drought tolerance capa- bilities conferred by different genes under various natural conditions have seldom been reported. We evaluated and compared the effects of two sets of transgenes, the drought- responsive genes （AtDREBIB and AtCBL1） and the root architecture-regulated genes （iaaM and AtCKX）, on drought tolerance in Nicotiana tabacum plants subjected to different conditions. The expression of AtCKX3 driven by a root- specific promoter PYKIO （designated hereafter as PIO; PIO：AtCKX3）, 35S：AtCKX3, or PlO：iaaM promoted root growth and development. Compared to plants harboring PIO：AtCKX3, 35S：AtCKX3, PlO：iaaM, or the empty vector, those carrying 35S：AtDREB1B, 35S：AtCBLl, or 35S：iaaM exhibited increased drought tolerance under laboratory- controlled conditions. Conversely, in field conditions, plants transformed with 35S：AtDREB1, 35S：AtCBL1, or 35S：iaaM were sensitive to drought stress. Under field conditions, drought stress dramatically reduced the growth and seed production of plants harboring 35S：AtDREBIB, 35S：A tCBL1, 35S：iaaM, or the empty vector, whereas it had little effect on plants carrying PIO：AtCKX3, 35S：AtCKX3, or PlO：iaaM. This study demonstrates that a plant＇s tolerance to drought stress changes with environmental conditions, and our results indicates that manipulating the expression of genes that control root architecture may be important for engineering plants with improved drought tolerance in natural conditions.