Rice Science ›› 2023, Vol. 30 ›› Issue (2): 87-91.DOI: 10.1016/j.rsci.2022.05.006

• Letter •     Next Articles

Chlorophyllide-a Oxygenase 1 (OsCAO1) Over-Expression Affects Rice Photosynthetic Rate and Grain Yield

Hu Ping1, Ma Jie1, Kang Shujing1,2, Li Sanfeng1, Wu Xianmei1, Zeng Longjun3, Lu Caolin1, He Rui1, He Huiying2, Shang Lianguang2, Rao Yuchun4, Zhu Xudong1, Xiong Guosheng3, Qian Qian1, Guo Longbiao1(), Wang Yuexing1()   

  1. 1State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
    2Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture / Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs / Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
    3Plant Phenomics Research Center, Nanjing Agricultural University, Nanjing 210095, China
    4College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua 321004, China
  • Received:2022-02-28 Accepted:2022-05-24 Online:2023-03-28 Published:2023-02-14
  • Contact: Wang Yuexing (wangyuexing@caas.cn);Guo Longbiao (guolongbiao@caas.cn)

Abstract: Leaf color and photosynthesis are important factors for rice growth and development. Hence, improving the photosynthetic rate is an effective approach for increasing rice yield. We isolated a gene, chlorophyllide-a oxygenase 1 (OsCAO1), which characterized a rice near-isogenic line named fgl (faded green leaf). Compared with its recurrent parent, Zhefu 802 (ZF802, an early-season indica rice variety), fgl had a faded green leaf color and lower chlorophyll (Chl) content, especially Chl b content. Furthermore, genetic and physiological analysis confirmed that leaf color was affected by the novel allele OsCAO1, which had a two-base pair deletion in the ninth exon. Subsequently, we over-expressed the OsCAO1 gene in ZF802. Interestingly, while OsCAO1 over-expression (OX) increased Chl b synthesis, the OX plants had a higher photosynthetic rate and heavier 1000-grain weight than ZF802. In conclusion, the novel allele OsCAO1 was involved in the positive regulation of leaf color, photosynthetic rate and rice yield.