Identification of Nucleus Sterility Candidate Genes using a Resequencing Technique in Sweet Pepper Sterile Line AB91

Abstract

Background : Breeding hybrids with nuclear malesterile lines is an important method for the cross breeding of sweet peppers. To date, few reports have been published on the nuclear malesterility gene of sweet pepper.Yet, there are approximately 20 pepper nuclear malesterility lines in the world. Results: Using the self-developed testing material, sweet pepper nuclear malesterile dual-purpose line AB91, the genome-wide resequencing technique was applied to firstly find that the mutation site causing the abortion of sweet pepper nuclear malesterility AB91 is on chromosome #5. The mutation gene Capana05g000747 was filtered out and validated by the flight mass spectrometry genotyping and quantitative real-time PCR method and determined to be the gene causing the abortion of sweet pepper nuclear male sterility AB91.The gene Capana05g000747 mutation site is a non-synonymous mutation site located at the 6th exon,the base C mutated into A, and the amino acid changed from alanine to serine. The three-dimensional protein structure of fertile and sterile plant Capana05g000747 was predicted. The results showed that the three-dimensional structure of the two proteins was differed significantly. Sequence alignment analysis showed that the gene Capana05g000747 has a similar function to gene At2g02148. The gene At2g02148 contains a pentatricopeptide repeatprotein which has important physiological functions in the gene expression process of organelles and is closely related to the performance of malesterility genes. Conclusions : This study revealed that Capana05g000747 was selected as an important candidate gene for sweet pepper nuclear male sterile testingmaterial AB91.This gene provides a theoretical and technical foundation for further cloning as well as transformation and utilization of the gene.