Biofortification of rice with the essential amino acid lysine: molecular characterization, nutritional evaluation, and field performance
Biofortification of rice with the essential amino acid lysine: molecular characterization, nutritional evaluation, and field performance
复制标题
用必需氨基酸赖氨酸对水稻进行生物强化：分子特征、营养评价和田间表现
DOI：
10.1093/jxb/erw209
复制
发表时间：
2016-07-01
影响因子：
6.9
通讯作者：
Liu, Qiao-quan
中科院分区：
文献类型：
--
作者：
Yang, Qing-qing;Zhang, Chang-quan;Liu, Qiao-quan
无标记的转基因大米，过度累积必需的氨基酸赖氨酸是通过将线条与赖氨酸的内生植物特异性和本构成工程相结合而产生的，并且在田间进行了评估。我们以前通过表达细菌天冬氨酸激酶和二氢二吡咯酸合酶并抑制水稻赖氨酸酮症还原酸还原酸盐还原酶/糖charopine脱氢酶活性，从而产生了赖氨酸含量增加的工程大米。然而，这些赖氨酸富集线中转基因的晶粒质量，田间性能和整合模式尚不清楚。在本研究中，我们选择了几种具有胚乳特异性或本构调节的精英转基因线，但缺乏可选的标记基因。所有靶基因都集成到水稻基因组中的基因内区域。通过上述两个转基因事件的组合获得了两种金字塔转基因系（高游离赖氨酸； HFL1和HFL2），其种子中的游离赖氨酸水平最高25倍。我们观察到总游离氨基酸的急剧增加，并且两种金字塔线中的总蛋白质含量略有增加。此外，在金字塔转基因大米中改善了一般的物理化学特性，但淀粉组成不受影响。现场试验表明，HFL转基因大米的生长是正常的，除了植物高度和谷物颜色略有差异。综上所述，这些发现将对高赖氨酸转基因大米的潜在商业化有用。
Marker-free transgenic rice that over-accumulates the essential amino acid lysine has been generated by combining lines with endosperm-specific and constitutive engineering of lysine, and has been evaluated in the field.Rice (Oryza sativa L.), a major staple crop worldwide, has limited levels of the essential amino acid lysine. We previously produced engineered rice with increased lysine content by expressing bacterial aspartate kinase and dihydrodipicolinate synthase and inhibiting rice lysine ketoglutarate reductase/saccharopine dehydrogenase activity. However, the grain quality, field performance, and integration patterns of the transgenes in these lysine-enriched lines remain unclear. In the present study, we selected several elite transgenic lines with endosperm-specific or constitutive regulation of the above key enzymes but lacking the selectable marker gene. All target transgenes were integrated into the intragenic region in the rice genome. Two pyramid transgenic lines (High Free Lysine; HFL1 and HFL2) with free lysine levels in seeds up to 25-fold that of wild type were obtained via a combination of the above two transgenic events. We observed a dramatic increase in total free amino acids and a slight increase in total protein content in both pyramid lines. Moreover, the general physicochemical properties were improved in pyramid transgenic rice, but the starch composition was not affected. Field trials indicated that the growth of HFL transgenic rice was normal, except for a slight difference in plant height and grain colour. Taken together, these findings will be useful for the potential commercialization of high-lysine transgenic rice.