Inactivation of the UGPase1 gene causes genic male sterility and endosperm chalkiness in rice (Oryza sativa L.).
A rice genic male-sterility gene ms-h is recessive and has a pleiotropic effect on the chalky endosperm. After fine mapping, nucleotide sequencing analysis of the ms-h gene revealed a single nucleotide substitution at the 3'-splice junction of the 14th intron of the UDP-glucose pyrophosphorylase 1 (UGPase1; EC2.7.7.9) gene, which causes the expression of two mature transcripts with abnormal sizes caused by the aberrant splicing. An in vitro functional assay showed that both proteins encoded by the two abnormal transcripts have no UGPase activity. The suppression of UGPase by the introduction of a UGPase1-RNAi construct in wild-type plants nearly eliminated seed set because of the male defect, with developmental retardation similar to the ms-h mutant phenotype, whereas overexpression of UGPase1 in ms-h mutant plants restored male fertility and the transformants produced T(1) seeds that segregated into normal and chalky endosperms. In addition, both phenotypes were co-segregated with the UGPase1 transgene in segregating T(1) plants, which demonstrates that UGPase1 has functional roles in both male sterility and the development of a chalky endosperm. Our results suggest that UGPase1 plays a key role in pollen development as well as seed carbohydrate metabolism.
Woo
Mi-Ok
MO
Department of Plant Science and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
Ham
Tae-Ho
TH
Ji
Hyeon-So
HS
Choi
Min-Seon
MS
Jiang
Wenzhu
W
Chu
Sang-Ho
SH
Piao
Rihua
R
Chin
Joong-Hyoun
JH
Kim
Jung-A
JA
Park
Bong Soo
BS
Seo
Hak Soo
HS
Jwa
Nam-Soo
NS
McCouch
Susan
S
Koh
Hee-Jong
HJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D051479:Plant Infertility / Q000235:genetics* / Q000502:physiology; D030821:Plants, Genetically Modified; D011058:Pollen / Q000254:growth & development; D034622:RNA Interference; D012639:Seeds / Q000201:enzymology / Q000235:genetics; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase / Q000235:genetics / Q000378:metabolism*
D005957:UTP-Glucose-1-Phosphate Uridylyltransferase