Send to

Choose Destination
J Exp Bot. 2016 Oct;67(18):5557-5569. Epub 2016 Sep 1.

Plastidic phosphoglucomutase and ADP-glucose pyrophosphorylase mutants impair starch synthesis in rice pollen grains and cause male sterility.

Author information

Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea.
Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA.
Department of Southern Area Crop Science, National Institute of Crop Science, Rural Development Administration, Milyang 50424, Korea.
Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Korea


To elucidate the starch synthesis pathway and the role of this reserve in rice pollen, we characterized mutations in the plastidic phosphoglucomutase, OspPGM, and the plastidic large subunit of ADP-glucose (ADP-Glc) pyrophosphorylase, OsAGPL4 Both genes were up-regulated in maturing pollen, a stage when starch begins to accumulate. Progeny analysis of self-pollinated heterozygous lines carrying the OspPGM mutant alleles, osppgm-1 and osppgm-2, or the OsAGPL4 mutant allele, osagpl4-1, as well as reciprocal crosses between the wild type (WT) and heterozygotes revealed that loss of OspPGM or OsAGPL4 caused male sterility, with the former condition rescued by the introduction of the WT OspPGM gene. While iodine staining and transmission electron microscopy analyses of pollen grains from homozygous osppgm-1 lines produced by anther culture confirmed the starch null phenotype, pollen from homozygous osagpl4 mutant lines, osagpl4-2 and osagpl4-3, generated by the CRISPR/Cas system, accumulated small amounts of starch which were sufficient to produce viable seed. Such osagpl4 mutant pollen, however, was unable to compete against WT pollen successfully, validating the important role of this reserve in fertilization. Our results demonstrate that starch is mainly polymerized from ADP-Glc synthesized from plastidic hexose phosphates in rice pollen and that starch is an essential requirement for successful fertilization in rice.


Oryza sativa ; ADP-glucose pyrophosphorylase; male sterility; phosphoglucomutase; plastid; pollen; starch.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center