Institute of Biotechnology and Nuclear Technology, Sichuan Academy of Agricultural Sciences, 106 Shizishan Road, Chengdu 610061, Sichuan, China.
Institute of Biotechnology and Nuclear Technology, Sichuan Academy of Agricultural Sciences, 106 Shizishan Road, Chengdu 610061, Sichuan, China.
Plant Sci. 2023 Jun;331:111661. doi: 10.1016/j.plantsci.2023.111661. Epub 2023 Feb 20.
For cereal crops, such as rice, the grain yield mainly comes from the accumulation of carbohydrates in the seed, which depends ultimately on photosynthesis during the growth period. To create early ripen variety, higher efficiency of photosynthesis is thus necessary to get higher grain yield with shorter growth period. In this study, flowering early was observed in the hybrid rice with overexpression of OsNF-YB4. Along with the flowering early, the hybrid rice also was shorter in plant height with less of leaves and internodes, but no changes of panicle length and leaf emergence. The grain yield was kept or even increased in the hybrid rice with shorter growth period. Transcription analysis revealed that Ghd7-Ehd1-Hd3a/RFT1 was activated early to promote the flowering transition in the overexpression hybrids. RNA-Seq study further showed that carbohydrate-related pathways were significantly altered in addition to circadian pathway. Notably, up-regulation of three pathways related to plant photosynthesis was observed, as well. Increased carbon assimilation with alteration of chlorophyll contents was subsequently detected in the following physiological experiments. All these results demonstrate that overexpression of OsNF-YB4 in the hybrid rice activates flowering early and improves photosynthesis resulting in better grain yield with shorter growth period.
对于谷类作物，如水稻，籽粒产量主要来自于种子中碳水化合物的积累，而这最终取决于生长期间的光合作用。为了创造早熟品种，需要更高的光合作用效率，才能在更短的生长周期内获得更高的籽粒产量。在这项研究中，过表达 OsNF-YB4 的杂交水稻表现出早期开花。伴随着早期开花，杂交水稻的株高变矮，叶片和节间变少，但穗长和叶片出现没有变化。在生长周期较短的杂交水稻中，产量保持甚至增加。转录分析显示，Ghd7-Ehd1-Hd3a/RFT1 被激活，从而促进了过表达杂种的开花转变。RNA-Seq 研究进一步表明，除了昼夜节律途径外，碳水化合物相关途径也发生了显著改变。值得注意的是，还观察到与植物光合作用相关的三个途径的上调。随后的生理实验检测到，碳同化增加，叶绿素含量发生改变。所有这些结果表明，在杂交水稻中过表达 OsNF-YB4 可提前开花并提高光合作用，从而在更短的生长周期内获得更好的籽粒产量。
