中文摘要：干旱是限制世界农业生产的第一要素，因此，使作物更耐旱是农业的主要目标。许多具有非生物胁迫耐受功能的基因已被发现，这些基因的过度表达赋予了转基因植物的耐旱性。在细胞分裂素生物合成中编码限速酶的异戊烯基转移酶基因（IPT）就是其中之一。当转基因IPT棉花在德克萨斯和亚利桑那州两个不同地点进行田间试验时，获得了不同的结果。为了解释这一现象，本文在不同时间下应用水分亏缺胁迫进行了灌溉试验。研究发现，在缺水胁迫条件西下，转基因IPT棉花表现出优于对照植物（即野生型和分离型非转基因植物）的产量优势。如果在开花前（营养期）出现缺水胁迫，转基因IPT棉花产量将优于对照植物；然而，如果在开花期（或繁殖期）发生缺水胁迫，则转IPT基因和对照棉花植株之间不会产生产量差异。
外文摘要：Drought is the No. 1 factor that limits agricultural production in the world, thus, making crops more drought tolerant is a major goal in agriculture. Many genes with functions in abiotic stress tolerance were identified, and overexpression of these genes confers increased drought tolerance in transgenic plants. The isopentenyltransferase gene (IPT) that encodes a rate limiting enzyme in cytokinin biosynthesis is one of them. Interestingly, when IPT-transgenic cotton was field-tested at two different sites, Texas and Arizona, different results were obtained. To explain this phenomenon, reduced irrigation experiments with different timing in applying water deficit stress were conducted. It was found that the timing of water deficit stress is critical for IPT-transgenic cotton to display its yield advantage over control plants (i. e. wild-type and segregated non-transgenic plants). If water deficit stress occurs before flowering (vegetative phase), IPT-transgenic cotton would outperform control plants; however, if water deficit stress occurs at or after flowering (reproductive phase), there would not be a yield difference between IPT-transgenic and control cotton plants. This result suggests that an early induction of IPT expression (before first flowering) is needed in order to realize the benefits of IPT-expression in transgenic plants that face water-deficit stress later in development.
作者：Zhu, Xunlu; Sun, Li; Kuppu, Sundaram; Hu, Rongbin; Mishra, Neelam; Smith, Jennifer; Esmaeili, Nardana; Herath, Maheshika; Gore, Michael A.; Payton, Paxton; Shen, Guoxin; Zhang, Hong
作者单位：Texas Tech Univ
期刊名称：SCIENTIFIC REPORTS
期刊影响因子：4.122
出版年份：2018
出版刊次：2
点击下载：野生型棉花与转IPT基因棉的产量差异取决于水分亏缺胁迫的应用