CDNA cloning, sequence characterization and expression analyses of a novel gene-TPI from pepper cytoplasmic male sterility (CMS)

Abstract

The complete coding sequence (CDS) of the gene triose phosphate isomerase (TPI) was amplified using the reverse transcriptase polymerase chain reaction based on the conserved sequence information of some Solanaceae plants and known highly homologous pepper ESTs. The results showed the pepper TPI gene encodes a protein of 254 amino acids that has high homology with the proteins of six other species, Solanum tuberosum(95%), Arabidopsis thaliana (87%), Ricinus communis, Vitis vinifera and Oryza sativa(87%) and Zea mays (85%). The pepper TPI gene was expressed in root, stem, leaf, flower, pericarp, placenta and seed. At the abortion stages, the ATP and NADH pool in male-sterile line were distinctly lower than those in the maintainer; The activities and expression levels of TPI in anthers of sterile line were obviously reduced, while levels in F1hybrid and maintainers kept normal, which indicated that stable transcripts of TPI are beneficial to keep the energy metabolism with a normal level. But when the restorer gene was transferred into CMS line, activities and expression level of TPI could be regulated by the restorer gene and kept stably. The restorer gene likely plays an important role in keeping the balance of the energy metabolism with a normal level during the microspore development. Key words: Pepper (Capsicum annuum L.), triose phosphate isomerase, cloning, characterization, cytoplasmic male sterility.