A duplicated coxI gene is associated with cytoplasmic male sterility in an alloplasmic Brassica juncea line derived from somatic hybridization with Diplotaxis catholica

Journal of genetics

P. Prakash²  V. Dinesh Kumar³  P. B. Kirti¹  Aruna Pathania²  Ashutosh²  Rajesh Kumar²  S. R. Bhat1²  K. K. Dwivedi²  V. L. Chopra² 

[1] Department of Plant Sciences, University of Hyderabad, 500046, India$$;National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, New Delhi 110012, India$$;Directorate of Oilseeds Research, Hyderabad, 500030, India$$

关键词: Brassica juncea;    coxI gene;    cytoplasmic male sterility;    somatic hybrid;    transcript variation.;   

DOI  :  

学科分类：生物科学（综合）

来源: Indian Academy of Sciences

【 摘 要 】

A cytoplasmic male sterile (CMS) line of Brassica juncea was derived by repeated backcrossing of the somatic hybrid (Diplotaxis catholica + B. juncea) to B. juncea. The new CMS line is comparable to euplasmic lines for almost all characters, except for flowers which bear slender, needle-like anthers with aborted pollen. Detailed Southern analysis revealed two copies of coxI gene in the CMS line. One copy, coxI-1 is similar to the coxI gene of B. juncea, whereas the second copy, coxI-2 is present in a novel rearranged region. Northern analysis with eight mitochondrial gene probes showed altered transcript pattern only for the coxI gene. Two transcripts of 2.0 and 2.4 kb, respectively, were detected in the CMS line. The novel 2.4 kb transcript was present in floral bud tissue but absent in the leaf tissue. In plants where male sterility broke down under high temperature during the later part of the growing season, the 2.4 kb coxI transcript was absent, which suggested its association with the CMS. The two coxI genes from the CMS line showed two amino acid changes in the coding region. The novel coxI gene showed unique repeats in the 5′ region suggesting recombination of mitochondrial genomes of the two species. The possible role of the duplicated coxI gene in causing male sterility is discussed.

【 授权许可】

Unknown