Biotechnology Bulletin ›› 2023, Vol. 39 ›› Issue (5): 152-159.doi: 10.13560/j.cnki.biotech.bull.1985.2022-1301

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Effect of SP1 on Panicle Architecture by Regulating Carbohydrate Remobilization

LIANG Cheng-gang1,2(), WANG Yan1, LI Tian3, OHSUGI Ryu2, AOKI Naohiro2()   

  1. 1. Institute of Plant Genetics and Breeding, College of Life Sciences, Guizhou Normal University, Guiyang 550001
    2. Faculty of Agriculture, The University of Tokyo, Tokyo 113-8657, Japan
    3. College of Agronomy, Sichuan Agricultural University, Chengdu 611130
  • Received:2022-10-23 Online:2023-05-26 Published:2023-06-08
  • Contact: LIANG Cheng-gang, AOKI Naohiro E-mail:201503001@gznu.edu.cn;aaokin@mail.ecc.u-tokyo.ac.jp

Abstract:

In order to explore the regulation of SP1 in the rice “source-sink” system and provide scientific reference for understanding the mechanism of rice panicle formation and molecular breeding of whole-rice silage, sp1 and WT were selected as materials for nitrogen treatment and plant growth analysis, phenotype identification, carbohydrate determination, and RT-qPCR detection. The results indicated that there was no phenotypic difference between sp1 and WT at 10 d after nitrogen treatment. However, sp1 showed significantly higher plant relative growth rate than WT under high and medium nitrogen treatment. Meanwhile, sp1 demonstrated higher value of the dry weight of leaf sheath, root and plant than WT at 24 d after nitrogen treatment, while a decrease in the content of nitrogen and an increase in the value of C/N ratio in leaf sheath. It was speculated that the abundant nitrogen improved plant growth of sp1, but the nitrogen stress impaired carbon-nitrogen balance in the leaf sheath. At heading stage, sp1 showed a significant decrease in plant height and a significant increase in tiller number, and shorter panicle with the occurrence of high-node tillering. At booting stage, there was little difference of the carbohydrates content in the stem and sheath between sp1 and WT. But, sp1 showed higher content of starch, sucrose in stem, and higher content of starch, sucrose, glucose and fructose in the leaf sheath at heading stage. SP1 highly expressed at the base of leaf sheath, which implied that the mutation of SP1 would inhibit the sucrose transport from the stem and sheath to the panicle and induce high-node tillering and short panicle. Rice SP1 gene is a candidate gene for molecular breeding of whole-rice silage.

Key words: panicle architecture, SP1 gene, carbohydrate, leaf sheath, whole-rice silage