Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA.
Plant Cell Rep. 2011 Jun;30(6):997-1006. doi: 10.1007/s00299-011-1003-4. Epub 2011 Jan 20.
Guar seed gum, consisting primarily of a high molecular weight galactomannan, is the most cost effective natural thickener, having broad applications in the food, cosmetics, paper, pharmaceutical and petroleum industries. The properties of the polymer can potentially be enhanced by genetic modification. Development of suitable endosperm-specific promoters for use in guar is desirable for metabolic engineering of the seed gum. A ~1.6 kb guar mannan synthase (MS) promoter region has been isolated. The MS promoter sequence was fused with the GUS reporter gene and overexpressed in the heterologous species alfalfa (Medicago sativa). The potential strength and specificity of the MS promoter was compared with those of the constitutive 35S promoter and the seed specific β-phaseolin promoter. Quantitative GUS assays revealed that the MS promoter directs GUS expression specifically in endosperm in transgenic alfalfa. Thus, the guar MS promoter could prove generally useful for directing endosperm-specific expression of transgenes in legume species.
胍尔胶，主要由高分子量半乳甘露聚糖组成，是最具成本效益的天然增稠剂，在食品、化妆品、造纸、制药和石油等行业有广泛的应用。通过遗传修饰可以提高聚合物的性能。在胍尔胶中使用合适的胚乳特异性启动子进行代谢工程是可取的。已经分离出一个约 1.6kb 的胍尔半乳甘露聚糖合酶 (MS) 启动子区域。MS 启动子序列与 GUS 报告基因融合，并在异源物种紫花苜蓿（Medicago sativa）中过表达。比较了 MS 启动子与组成型 35S 启动子和种子特异性β-伴球蛋白启动子的潜在强度和特异性。定量 GUS 分析表明，MS 启动子在转基因紫花苜蓿的胚乳中特异性地指导 GUS 表达。因此，胍尔 MS 启动子可以证明在豆科植物中转基因胚乳特异性表达中具有普遍的用途。
