Department of Bioscience and Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.
Plant Mol Biol. 2024 Jun 14;114(4):73. doi: 10.1007/s11103-024-01472-7.
Functional genomics through transgenesis has provided faster and more reliable methods for identifying, characterizing, and utilizing genes or quantitative trait loci linked to agronomic traits to target yield. The present study explored the role of Big Grain1 (BG1) gene of rice (Oryza sativa L.) in yield improvement of crop plants. We aimed to identify the genetic variation of OsBG1 in various indica rice cultivars by studying the allelic polymorphism of the gene, while also investigating the gene's potential to increase crop yield through the transgenic approach. Our study reports the presence of an extra 393 bp sequence having two 6 bp enhancer elements in the 3' regulatory sequence of OsBG1 in the large-grain cultivar IR64 but not in the small-grain cultivar Badshahbhog. A single copy of the OsBG1 gene in both the cultivars and a 4.1-fold higher expression of OsBG1 in IR64 than in Badshahbhog imply that the grain size is positively correlated with the level of OsBG1 expression in rice. The ectopic expression of OsBG1 under the endosperm-specific glutelin C promoter in Badshahbhog enhanced the flag leaf length, panicle weight, and panicle length by an average of 33.2%, 33.7%, and 30.5%, respectively. The length of anthers, spikelet fertility, and grain yield per plant increased in transgenic rice lines by an average of 27.5%, 8.3%, and 54.4%, respectively. Heterologous expression of OsBG1 under the constitutive 2xCaMV35S promoter improved the number of seed pods per plant and seed yield per plant in transgenic tobacco lines by an average of 2.2-fold and 2.6-fold, respectively. Improving crop yield is crucial to ensure food security and socio-economic stability, and identifying suitable genetic factor is the essential step towards this endeavor. Our findings suggest that the OsBG1 gene is a promising candidate for improving the grain yield of monocot and dicot plant systems by molecular breeding and genetic engineering.
通过转基因的功能基因组学为鉴定、描述和利用与农艺性状相关的基因或数量性状位点提供了更快、更可靠的方法，以提高产量。本研究探讨了水稻（Oryza sativa L.）Big Grain1（BG1）基因在作物产量改良中的作用。我们旨在通过研究基因的等位基因多态性来鉴定不同籼稻品种中 OsBG1 的遗传变异，同时通过转基因方法研究该基因增加作物产量的潜力。我们的研究报告称，在大粒品种 IR64 中，OsBG1 的 3'调控序列存在额外的 393bp 序列，其中包含两个 6bp 的增强子元件，而在小粒品种 Badshahbhog 中则不存在。两个品种中均存在 OsBG1 的单个拷贝，以及 OsBG1 在 IR64 中的表达水平比 Badshahbhog 高 4.1 倍，这表明在水稻中，粒型与 OsBG1 表达水平呈正相关。在 Badshahbhog 中，OsBG1 在胚乳特异性谷蛋白 C 启动子的异位表达分别使旗叶长度、穗重和穗长平均增加了 33.2%、33.7%和 30.5%。花药长度、小穗育性和单株产量分别平均增加了 27.5%、8.3%和 54.4%。在转基因烟草系中，OsBG1 异源表达在组成型 2xCaMV35S 启动子下，分别使每株植物的种子荚数和种子产量平均提高了 2.2 倍和 2.6 倍。提高作物产量对于确保粮食安全和社会经济稳定至关重要，而确定合适的遗传因素是实现这一目标的必要步骤。我们的研究结果表明，OsBG1 基因是通过分子育种和遗传工程提高单子叶和双子叶植物系统谷物产量的有前途的候选基因。
