In crop plants, to cope up with the demand of food for rising population, revolutionary crop improvement programmes are being implemented for higher and higher yields. Abiotic stress, especially at flowering stage, causes drastic effect on yield in plants. Deforestation and urbanization made the water table very low and changed the climate which led to untimely and unforeseen rains which affect the yield of a crop through stress, both by lack of water as well as water logging (abiotic stress). Development of tolerant plants through breeding is a time-consuming programme and does not perform well in normal conditions. Development of stress-tolerant plants through transgenic technology is the better solution. Maize is a major crop used as food and fodder and has the commercial value in ethanol production. Hence, the genes viz., nced (9-cis-epoxycarotenoid dioxygenase) and rpk (receptor-like protein kinase), which play the key roles in the abscisic acid pathway and upstream component in ABA signaling have been transferred into maize plants through Agrobacterium-mediated transformation by optimizing several parameters to obtain maximum frequency of transformation. Cultures raised from immature embryos of 2-mm size isolated from maize cobs, 12–15 days after pollination, were used for transformation. rpk and nced genes under the control of leaP and salT promoters respectively, cloned using gateway technology, have been introduced into elite maize inbred lines. Maximum frequency of transformation was observed with the callus infected after 20 days of inoculation by using 100 μM acetosyringone, 10 min infection time, and 2 days incubation period after co-cultivation resulted in maximum frequency of transformation (6%) in the NM5884 inbred line. Integration of the genes has been confirmed with molecular characterization by performing PCRs with marker as well as gene-specific primers and through southern hybridization. Physiological and biochemical characterization was done in vitro (artificial stress) and in vivo (pot experiments). Changes in the parameters which affect the transformation frequency yielded maximum frequency of transformation with 20-day-old callus in the NM5884 inbred line. Introducing two or more genes using gateway technology is useful for developing stable transgenic plants with desired characters, abiotic stress tolerance in this study.

中文翻译：

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通过农杆菌介导的转化操纵 ABA 信号来开发耐旱的稳定转基因玉米植物

在农作物方面，为了满足不断增长的人口对食物的需求，正在实施革命性的作物改良计划以提高产量。非生物胁迫，尤其是在开花期，会对植物的产量产生巨大影响。森林砍伐和城市化使地下水位非常低并改变了气候，导致不合时宜和不可预见的降雨，通过缺水和水涝（非生物压力）压力影响作物产量。通过育种培育耐受性植物是一项耗时的计划，并且在正常条件下表现不佳。通过转基因技术开发抗逆植物是更好的解决方案。玉米是用作食物和饲料的主要作物，在乙醇生产中具有商业价值。因此，基因即，已通过农杆菌介导的转化，通过优化几个参数，将在脱落酸途径和 ABA 信号上游组分中起关键作用的 nced（9-顺式环氧类胡萝卜素双加氧酶）和 rpk（受体样蛋白激酶）转移到玉米植株中以获得最大的变换频率。从授粉后 12-15 天从玉米棒子中分离出的 2 毫米大小的未成熟胚培养的培养物用于转化。分别在 leaP ​​和 salT 启动子控制下的 rpk 和 nced 基因，使用网关技术克隆，已被引入优良玉米自交系。通过使用 100 μM 乙酰丁香酮，10 分钟感染时间，在接种 20 天后感染愈伤组织时观察到最大转化频率，共培养后 2 天的潜伏期导致 NM5884 自交系的最大转化频率 (6%)。通过使用标记物和基因特异性引物进行 PCR 以及通过 Southern 杂交，已通过分子表征证实了基因的整合。在体外（人工应激）和体内（盆栽实验）进行生理和生化表征。影响转化频率的参数的变化产生了 NM5884 自交系 20 天龄愈伤组织的最大转化频率。在本研究中，使用网关技术引入两个或多个基因有助于开发具有所需特性、非生物胁迫耐受性的稳定转基因植物。通过使用标记物和基因特异性引物进行 PCR 以及通过 Southern 杂交，已通过分子表征证实了基因的整合。在体外（人工应激）和体内（盆栽实验）进行生理和生化表征。影响转化频率的参数的变化产生了 NM5884 自交系 20 天龄愈伤组织的最大转化频率。在本研究中，使用网关技术引入两个或多个基因有助于开发具有所需特性、非生物胁迫耐受性的稳定转基因植物。通过使用标记物和基因特异性引物进行 PCR 以及通过 Southern 杂交，已通过分子表征证实了基因的整合。在体外（人工应激）和体内（盆栽实验）进行生理和生化表征。影响转化频率的参数的变化产生了 NM5884 自交系 20 天龄愈伤组织的最大转化频率。在本研究中，使用网关技术引入两个或多个基因有助于开发具有所需特性、非生物胁迫耐受性的稳定转基因植物。在体外（人工应激）和体内（盆栽实验）进行生理和生化表征。影响转化频率的参数的变化产生了 NM5884 自交系 20 天龄愈伤组织的最大转化频率。在本研究中，使用网关技术引入两个或多个基因有助于开发具有所需特性、非生物胁迫耐受性的稳定转基因植物。在体外（人工应激）和体内（盆栽实验）进行生理和生化表征。影响转化频率的参数的变化产生了 NM5884 自交系 20 天龄愈伤组织的最大转化频率。在本研究中，使用网关技术引入两个或多个基因有助于开发具有所需特性、非生物胁迫耐受性的稳定转基因植物。