Daisuke Fujita, Kurniawan Rudi Trijatmiko, Analiza Grubanzo Tagle, Maria Veronica Sapasap, Yohei Koide, Kazuhiro Sasaki, Nikolaos Tsakirpaloglou, Ritchel Bueno Gannaban, Takeshi Nishimura, Seiji Yanagihara, Yoshimichi Fukuta, Tomokazu Koshiba, Inez Hortense Slamet-Loedin, Tsutomu Ishimaru, Nobuya Kobayashi
Proceedings of the National Academy of Sciences of the United States of America 110 51 20431 - 20436 2013年12月17日
[査読有り][通常論文] Increasing crop production is essential for securing the future food supply in developing countries in Asia and Africa as economies and populations grow. However, although the Green Revolution led to increased grain production in the 1960s, no major advances have been made in increasing yield potential in rice since then. In this study, we identified a gene, SPIKELET NUMBER (SPIKE), from a tropical japonica rice landrace that enhances the grain productivity of indica cultivars through pleiotropic effects on plant architecture. Map-based cloning revealed that SPIKE was identical to NARROW LEAF1 (NAL1), which has been reported to control vein pattern in leaf. Phenotypic analyses of a near-isogenic line of a popular indica cultivar, IR64, and overexpressor lines revealed increases in spikelet number, leaf size, root system, and the number of vascular bundles, indicating the enhancement of source size and translocation capacity as well as sink size. The near-isogenic line achieved 13-36% yield increase without any negative effect on grain appearance. Expression analysis revealed that the gene was expressed in all cell types: panicles, leaves, roots, and culms supporting the pleiotropic effects on plant architecture. Furthermore, SPIKE increased grain yield by 18% in the recently released indica cultivar IRRI146, and increased spikelet number in the genetic background of other popular indica cultivars. The use of SPIKE in rice breeding could contribute to food security in indica- growing regions such as South and Southeast Asia.