Expression Pattern of Class B Gene PAP3 in Flower Development of Pepper

Huolin Shen,Fengjiao Da,Ning Ma,Chen Liu,Xin Li

doi:10.3390/ijms141224643

Abstract

Class B gene APETALA3 (AP3) plays a key role in the development of petals and stamens. Here, we investigated the expression pattern of PAP3 gene (genbank accession number: HM104635) in the buds of cytoplasmic male sterility line 121A and its near-isogenic restorer line 121C at four developmental stages and analyzed the possible association between Class B genes and cytoplasmic male sterility of pepper. Semi-quantitative PCR and quantitative real-time RT-PCR (qRT-PCR) as well as RNA in situ hybridization showed increased expression of PAP3 at late phase of anther development and its higher expression in restorer line compared with sterility line indicating PAP3’s role at late developmental stage of anther and suppressed expression in sterility line. RNA in situ hybridization showed Class B gene features: high abundance in stamen and petal; lower expression in pistil; no expression in sepal. Results of transient expression in onion epidermal cells also showed PAP3 localized in the nucleus, which is consistent with the expression pattern of transcription factors of MADS-box gene family.

Highlights

Pepper (Capsicum annuum L.), one of the world’s most important vegetable crops with remarkable food value and economic value, is a flowering plant belonging to Solanaceae
Regulation on the cytoplasmic male sterility (CMS) associated mitochondrial genes may lead to the expression change of nuclear genes, and expression of mitochondrial sterility genes themselves can be inhibited by nuclear genes [5,6,7]
PCR amplification based on PAP3 gene of restorer line produced 924 bp band

Summary

Introduction

Pepper (Capsicum annuum L.), one of the world’s most important vegetable crops with remarkable food value and economic value, is a flowering plant belonging to Solanaceae. 2013, 14 using cytoplasmic male sterility (CMS) represents an ideal method in seed production of crops, including pepper, due to its low cost and the high purity of seeds [1,2,3,4]. Genes of cytoplasm and nucleus regulate CMS. Regulation on the CMS associated mitochondrial genes may lead to the expression change of nuclear genes, and expression of mitochondrial sterility genes themselves can be inhibited by nuclear genes [5,6,7]. Two CMS genes, orf507 and atp, were found in the pepper mitochondria [8]. As for the fertility restorer gene (Rf), studies reported screening using analyses based on the differenced expression but no functional genes were identified [9,10,11]

Results

Discussion

Conclusion