Map-Based Cloning, Phylogenetic, and Microsynteny Analyses of ZmMs20 Gene Regulating Male Fertility in Maize.

Yanbo Wang,Dongcheng Liu,Youhui Tian,Xueli An,Zhenying Dong,Ziwen Li,Suowei Wu,Jinping Li,Xiangyuan Wan,Simiao Zhang,Jianxi Bao

doi:10.3390/ijms20061411

Abstract

Genic male sterility (GMS) mutant is a useful germplasm resource for both theory research and production practice. The identification and characterization of GMS genes, and assessment of male-sterility stability of GMS mutant under different genetic backgrounds in Zea may (maize) have (1) deepened our understanding of the molecular mechanisms controlling anther and pollen development, and (2) enabled the development and efficient use of many biotechnology-based male-sterility (BMS) systems for hybrid breeding. Here, we reported a complete GMS mutant (ms20), which displays abnormal anther cuticle and pollen development. Its fertility restorer gene ZmMs20 was found to be a new allele of IPE1 encoding a glucose methanol choline (GMC) oxidoreductase involved in lipid metabolism in anther. Phylogenetic and microsynteny analyses showed that ZmMs20 was conserved among gramineous species, which provide clues for creating GMS materials in other crops. Additionally, among the 17 maize cloned GMS genes, ZmMs20 was found to be similar to the expression patterns of Ms7, Ms26, Ms6021, APV1, and IG1 genes, which will give some clues for deciphering their functional relationships in regulating male fertility. Finally, two functional markers of ZmMs20/ms20 were developed and tested for creating maize ms20 male-sterility lines in 353 genetic backgrounds, and then an artificial maintainer line of ms20 GMS mutation was created by using ZmMs20 gene, ms20 mutant, and BMS system. This work will promote our understanding of functional mechanisms of male fertility and facilitate molecular breeding of ms20 male-sterility lines for hybrid seed production in maize.

Highlights

Male sterility is a common phenomenon in higher plants and widely used in crop hybrid seed production
AT1,hAe2),sbeeecdamseestmtianllger oanfdmwsi2lt0edw(Faigsurneo1rAm3,Aal4)w, ahndendidpnooltligneanteeradte wmaituhreWT pollens, indicating tphoalltenthgerafinesm(Faigleurfee1rAti5l,iAty6).oTfhme sse2ed0swettainsguonf mafs2fe0cwtaesdn.ormal when pollinated with wild type (WT) pollens, indicating that the female fertility of ms20 was unaffected
Loss-function of IPE1 leads to similar defective phenotypes as ms20 mutant, for instance, absence of the typical Spaghetti-like anther cutin pattern, disappearance of Ubisch bodies, and arrested pollen exine accumulation [30]

Summary

Introduction

Male sterility is a common phenomenon in higher plants and widely used in crop hybrid seed production. According to the inheritance characteristic, it can be divided into cytoplasmic male sterility (CMS) and genic male sterility (GMS). CMS is caused by a toxic protein in the cytoplasm, and the fertility can be rescued by restorer genes in the nucleus. GMS usually results from the loss-function of genic genes, mainly participating in anther and pollen development. Anther locules are composed of center-localized meiocyte cells, which are surrounded by four somatic cell layers. From stamen primordia initiation to mature pollen formation, thousands of genes likely take part in this complicated process. Hundreds of GMS mutants have been found, while only 17 GMS genes have been cloned in maize. Nine genes were reported to participate in the ontogeny of anther cuticle and pollen exine [1]

Methods

Results

Conclusion