Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, Japan.
Plant Mol Biol. 2011 May;76(1-2):47-56. doi: 10.1007/s11103-011-9765-1. Epub 2011 Mar 16.
The endosperm of cereal grains is an important resource for both food and feed. It contains three major types of tissue: starchy endosperm, the aleurone layer, and transfer cells. To improve grain quality and quantity using molecular methods, control of transgene expression directed by distinct temporal and spatial promoter activity is necessary. To identify aleurone layer-specific and/or transfer cell-specific promoters in rice, microarray analyses were performed, comparing the aleurone layer containing transfer cells and the other reproductive and vegetative tissues. After confirmation by RT-PCR analysis, we identified two putative aleurone layer and/or transfer cell-specific genes, AL1 and AL2. The promoter regions of these genes and β-glucuronidase (GUS) fusion constructs were stably transformed into rice. The GUS expression patterns indicated that the AL1 promoter was active exclusively in the dorsal aleurone layer adjacent to the main vascular bundle. In rice, transfer cells are differentiated in this region. Therefore, the promoter of the AL1 gene exhibits transfer cell-containing region-specific activity. The AL1 gene encodes a putative anthranilate N-hydroxycinnamoyl/benzoyltransferase. The promoter of this gene will be useful for enhancing uptake of nutrients from the mother cells and protecting filial seeds from pathogen attack.
谷物的胚乳是食品和饲料的重要资源。它包含三种主要组织类型：淀粉胚乳、糊粉层和传递细胞。为了使用分子方法提高谷物的质量和数量，需要控制由不同时空启动子活性指导的转基因表达。为了在水稻中鉴定糊粉层特异性和/或传递细胞特异性启动子，进行了微阵列分析，比较了含有传递细胞的糊粉层与其他生殖和营养组织。通过 RT-PCR 分析确认后，我们鉴定了两个假定的糊粉层和/或传递细胞特异性基因，AL1 和 AL2。这些基因的启动子区域和β-葡萄糖醛酸酶（GUS）融合构建体被稳定转化到水稻中。GUS 表达模式表明，AL1 启动子仅在靠近主维管束的背侧糊粉层中活跃。在水稻中，传递细胞在该区域分化。因此，AL1 基因的启动子表现出具有传递细胞的区域特异性活性。AL1 基因编码一个假定的邻氨基苯甲酸 N-羟肉桂酰/苯甲酰基转移酶。该基因的启动子将有助于从母细胞中吸收营养物质，并保护子代种子免受病原体的攻击。
