Expression of the nuclear gene TaFAd is under mitochondrial retrograde regulation in anthers of male sterile wheat plants with timopheevii cytoplasm

• Published in: Journal of experimental botany 2008-04, Vol.59 (6), p.1375-1381
• Main Authors: Xu, Pei, Yang, Yuwen, Zhang, Zhengzhi, Chen, Weihua, Zhang, Caiqin, Zhang, Lixia, Zou, Sixiang, Ma, Zhengqiang
• Format: Article
• Language: English
• Subjects: Anthers; Biological and medical sciences; Cell physiology; CMS; Complementary DNA; Cytoplasm; Epidermal cells; FAd subunit; FoF1-ATP synthase; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Genes; Molecular and cellular biology; Plants; Research Papers; retrograde regulation; Rice; Signal transduction; Soybeans; Wheat
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ern068

Alterations of mitochondrial-encoded subunits of the FoF₁-ATP synthase are frequently associated with cytoplasmic male sterility (CMS) in plants; however, little is known about the relationship of the nuclear encoded subunits of this enzyme with CMS. In the present study, the full cDNA of the gene TaFAd that encodes the putative FAd subunit of the FoF₁-ATP synthase was isolated from the wheat (Triticum aestivum) fertility restorer '2114' for timopheevii cytoplasm-based CMS. The deduced 238 amino acid polypeptide is highly similar to its counterparts in dicots and other monocots but has low homology to its mammalian equivalents. TaFAd is a single copy gene in wheat and maps to the short arm of the group 6 chromosomes. Transient expression of the TaFAd-GFP fusion in onion epidermal cells demonstrated TaFAd's mitochondrial location. TaFAd was expressed abundantly in stem, leaf, anther, and ovary tissues of 2114. Nevertheless, its expression was repressed in anthers of CMS plants with timopheevii cytoplasm. Genic male sterility did not affect its expression in anthers. The expression of the nuclear gene encoding the 20 kDa subunit of Fo was down-regulated in a manner similar to TaFAd in the T-CMS anthers while that of genes encoding the 6 kDa subunit of Fo and the γ subunit of F₁ was unaffected. These observations implied that TaFAd is under mitochondrial retrograde regulation in the anthers of CMS plants with timopheevii cytoplasm.