Chinese Bulletin of Botany ›› 2021, Vol. 56 ›› Issue (5): 520-532.DOI: 10.11983/CBB21119

• EXPERIMENTAL COMMUNICATIONS • Previous Articles     Next Articles

Map-based Cloning and Natural Variation Analysis of the PAL3 Gene Controlling Panicle Length in Rice

Jiangyuan Shang, Yan Chun, Xueyong Li*()   

  1. National Key Facility for Crop Gene Resource and Genetic Improvement/Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China
  • Received:2021-07-21 Accepted:2021-09-16 Online:2021-09-01 Published:2021-09-16
  • Contact: Xueyong Li

Abstract: Panicle architecture is one of the key factors determining the rice (Oryza sativa) grain yield. In this study, four short panicle mutants were identified from an EMS (ethyl methane sulfonate) mutant library of a japonica vareity Shengdao 808 (SD808). The panicle length, primary branch number, secondary branch number and grain number per panicle of these mutants were decreased in various degrees. Map-based cloning showed that these mutants were controlled by the gene PAL3 (PANICLE LENGTH 3) which encodes a peptide transporter with 12 transmembrane domains. The point mutations of pal3-1 and pal3-2 resulted in non-synonymous mutations of amino acids in the conserved region; the point mutation of pal3-3 resulted in the mis-splicing of the first exon and intron; and the point mutation of pal3-4 resulted in the premature termination of translation and thus the deletion of the 12th transmembrane domain. Through haplotype analysis, nine haplotypes of PAL3 were identified, including three major haplotypes (Hap1-Hap3). Hap1 is dominated by japonica accessions, Hap2 contains both indica and japonica accessions, while Hap3 is dominated by indica accessions. Hap1 originated from O. rufipogon, while Hap2 and Hap3 may originate from O. nivara. Statistical analysis showed that the panicle length of Hap3 was significantly higher than that of Hap1 and Hap2, indicating that Hap3 may have the potential to improve the panicle length. In conclusion, this study revealed the important role of the peptide transporter in regulating rice panicle architecture and thus provides a new theoretical basis for rice panicle architecture improvement.

Key words: rice, panicle architecture, map-based cloning, peptide transporter, natural variation