Mitochondrially-targeted expression of a cytoplasmic male sterility-associated orf220 gene causes male sterility in Brassica juncea

BMC Plant Biology

Research Article

Jinghua Yang¹  Xunyan Liu¹  Xiaodong Yang¹  Mingfang Zhang¹ 

[1] Laboratory of Genetic Resources & Functional Improvement for Horticultural Plants, Department of Horticulture, Zhejiang University, 310029, Hangzhou, P. R., China;Laboratory of Horticultural Plant Growth, Development & Quality Improvement, Ministry of Agriculture, 310029, Hangzhou, P. R., China;

关键词: Transgenic Plant;    Male Sterility;    Cytoplasmic Male Sterility;    Pollen Development;    Chimeric Gene;   

DOI  :  10.1186/1471-2229-10-231

 received in 2010-05-11, accepted in 2010-10-26,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe novel chimeric open reading frame (orf) resulting from the rearrangement of a mitochondrial genome is generally thought to be a causal factor in the occurrence of cytoplasmic male sterility (CMS). Both positive and negative correlations have been found between CMS-associated orfs and the occurrence of CMS when CMS-associated orfs were expressed and targeted at mitochondria. Some orfs cause male sterility or semi-sterility, while some do not. Little is currently known about how mitochondrial factor regulates the expression of the nuclear genes involved in male sterility. The purpose of this study was to investigate the biological function of a candidate CMS-associated orf220 gene, newly isolated from cytoplasmic male-sterile stem mustard, and show how mitochondrial retrograde regulated nuclear gene expression is related to male sterility.ResultsIt was shown that the ORF220 protein can be guided to the mitochondria using the mitochondrial-targeting sequence of the β subunit of F1-ATPase (atp2-1). Transgenic stem mustard plants expressed the chimeric gene containing the orf220 gene and a mitochondrial-targeting sequence of the β subunit of F1-ATPase (atp2-1). Transgenic plants were male-sterile, most being unable to produce pollen while some could only produce non-vigorous pollen. The transgenic stem mustard plants also showed aberrant floral development identical to that observed in the CMS stem mustard phenotype. Results obtained from oligooarray analysis showed that some genes related to mitochondrial energy metabolism were down-regulated, indicating a weakening of mitochondrial function in transgenic stem mustard. Some genes related to pollen development were shown to be down-regulated in transgenic stem mustard and the expression of some transcription factor genes was also altered.ConclusionThe work presented furthers our understanding of how the mitochondrially-targeted expression of CMS-associated orf220 gene causes male sterility through retrograde regulation of nuclear gene expression in Brassica juncea.

【 授权许可】

Unknown   
© Yang et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.