Linkage Mapping of Stem Saccharification Digestibility in Rice

PLoS One. 2016 Jul 14;11(7):e0159117. doi: 10.1371/journal.pone.0159117. eCollection 2016.

Abstract

Rice is the staple food of almost half of the world population, and in excess 90% of it is grown and consumed in Asia, but the disposal of rice straw poses a problem for farmers, who often burn it in the fields, causing health and environmental problems. However, with increased focus on the development of sustainable biofuel production, rice straw has been recognized as a potential feedstock for non-food derived biofuel production. Currently, the commercial realization of rice as a biofuel feedstock is constrained by the high cost of industrial saccharification processes needed to release sugar for fermentation. This study is focused on the alteration of lignin content, and cell wall chemotypes and structures, and their effects on the saccharification potential of rice lignocellulosic biomass. A recombinant inbred lines (RILs) population derived from a cross between the lowland rice variety IR1552 and the upland rice variety Azucena with 271 molecular markers for quantitative trait SNP (QTS) analyses was used. After association analysis of 271 markers for saccharification potential, 1 locus and 4 pairs of epistatic loci were found to contribute to the enzymatic digestibility phenotype, and an inverse relationship between reducing sugar and lignin content in these recombinant inbred lines was identified. As a result of QTS analyses, several cell-wall associated candidate genes are proposed that may be useful for marker-assisted breeding and may aid breeders to produce potential high saccharification rice varieties.

MeSH terms

  • Biofuels
  • Cellulose / metabolism*
  • Chromosome Mapping*
  • Chromosomes, Plant
  • Lignin / genetics*
  • Lignin / metabolism
  • Oryza / genetics*
  • Oryza / metabolism
  • Plant Stems / metabolism*
  • Polymorphism, Single Nucleotide
  • Quantitative Trait Loci

Substances

  • Biofuels
  • Cellulose
  • Lignin

Grants and funding

The research was funded by Major State Basic Research Development Program (973 Program, grant no. 2015CB150200); Zhejiang Provincial Natural Science Foundation of China (Grant No. LZ15C020001); National Natural Science Foundation of China (Grant No. 31570183; 31529001) and UK-China partnering award from BBSRC of UK (Grant No BB/H531419). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.