Molecular characterization and application of a novel cytoplasmic male sterility-associated mitochondrial sequence in rice.
BACKGROUND
Cytoplasmic male sterility (CMS) is a maternally inherited inability to produce functional pollen found in numerous flowering plant species. CMS is associated with mitochondrial DNA mutation, novel chimeric open reading frames (ORFs), and rearrangement of coding and noncoding regions of the mitochondrial genome.


RESULTS
BLAST (Basic Local Alignment Search Tool) analysis indicated that L-sp1, a new sequence-characterized amplified region, is non-homologous to atp6-orfH79 (or atp6-orf79) and WA352 cloned CMS-associated genes. L-sp1 was found in 11 of 102 wild rice accessions belonging to four AA genome species: Oryza rufipogon, Oryza nivara, Oryza glumaepatula, and Oryza meridionalis. Using L-sp1, two new CMS lines were developed, from either low natural fertility plants or sterile plants, by backcrossing BC1F1 with Yuetai B. Northern blot and RT-PCR revealed that L-sp1 was only expressed in the anthers of w1/YTB, w2/YTB, w1/YTB//YTB, and w2/YTB//YTB when in the same cytoplasm background.


CONCLUSIONS
L-sp1 is a single-copy chimeric CMS-associated gene found in the mitochondrial genome. It can be expressed in anthers with the same specific cytoplasm background, and will be a useful molecular marker for the development and marker-assisted selection of new CMS lines.
Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Science, South-Central University for Nationalities, Wuhan, 430074, China. yanptan@mail.scuec.edu.cn.
Yanping
Y
Tan
Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Science, South-Central University for Nationalities, Wuhan, 430074, China. bio.xuxin@gmail.com.
Xin
X
Xu
Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Science, South-Central University for Nationalities, Wuhan, 430074, China. wangchuntai@mail.scuec.edu.cn.
Chuntai
C
Wang
Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Science, South-Central University for Nationalities, Wuhan, 430074, China. cheng_gang@aliyun.com.
Gang
G
Cheng
Key Laboratory of MOE for Plant Developmental Biology, College of Life Science, Wuhan University, Wuhan, 430072, China. shaoqingli@whu.edu.cn.
Shaoqing
S
Li
Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Science, South-Central University for Nationalities, Wuhan, 430074, China. xqliuw@mail.scuec.edu.cn.
Xuequn
X
Liu
D004272:DNA, Mitochondrial; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005819:Genetic Markers; D007178:Inbreeding; D008928:Mitochondria / Q000235:genetics*; D016366:Open Reading Frames; D012275:Oryza / Q000235:genetics*; D011058:Pollen / Q000235:genetics; D012098:Reproduction / Q000235:genetics; D014158:Transcription, Genetic
D004272:DNA, Mitochondrial; D005819:Genetic Markers