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Identification of Genes Potentially Associated with the Fertility Instability of S-Type Cytoplasmic Male Sterility in Maize via Bulked Segregant RNA-Seq

View Article: PubMed Central - PubMed

ABSTRACT

S-type cytoplasmic male sterility (CMS-S) is the largest group among the three major types of CMS in maize. CMS-S exhibits fertility instability as a partial fertility restoration in a specific nuclear genetic background, which impedes its commercial application in hybrid breeding programs. The fertility instability phenomenon of CMS-S is controlled by several minor quantitative trait locus (QTLs), but not the major nuclear fertility restorer (Rf3). However, the gene mapping of these minor QTLs and the molecular mechanism of the genetic modifications are still unclear. Using completely sterile and partially rescued plants of fertility instable line (FIL)-B, we performed bulk segregant RNA-Seq and identified six potential associated genes in minor effect QTLs contributing to fertility instability. Analyses demonstrate that these potential associated genes may be involved in biological processes, such as floral organ differentiation and development regulation, energy metabolism and carbohydrates biosynthesis, which results in a partial anther exsertion and pollen fertility restoration in the partially rescued plants. The single nucleotide polymorphisms (SNPs) identified in two potential associated genes were validated to be related to the fertility restoration phenotype by KASP marker assays. This novel knowledge contributes to the understanding of the molecular mechanism of the partial fertility restoration of CMS-S in maize and thus helps to guide the breeding programs.

No MeSH data available.


Related in: MedlinePlus

Paraffin slides show normal microspore development in the partially rescued FIL-B.Microscopic images of anther transverse sections of Jing724 (A) and the partially rescued (B) and sterile (C) individuals of FIL-B. The black round microspores were considered as normal. The scale bars represent 100 μm.
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pone.0163489.g003: Paraffin slides show normal microspore development in the partially rescued FIL-B.Microscopic images of anther transverse sections of Jing724 (A) and the partially rescued (B) and sterile (C) individuals of FIL-B. The black round microspores were considered as normal. The scale bars represent 100 μm.

Mentions: To test pollen development during the microspore stage in the anthers, we observed the anther dissection under a light microscope. However, the development differed in the sterile and partially rescued anthers during telophase of the uninucleate microspores (Fig 3). Although the development and structure of tapetum were the same in both genotypes, all of the microspores collapsed in the sterile anthers, while a small proportion of the microspores had normal development in the partially rescued plants. The individual normal microspores from the FIL-B partially rescued plants might lead to normal mature pollen, which is consistent with the pollen staining data and further confirms the fertility instability of FIL-B.


Identification of Genes Potentially Associated with the Fertility Instability of S-Type Cytoplasmic Male Sterility in Maize via Bulked Segregant RNA-Seq
Paraffin slides show normal microspore development in the partially rescued FIL-B.Microscopic images of anther transverse sections of Jing724 (A) and the partially rescued (B) and sterile (C) individuals of FIL-B. The black round microspores were considered as normal. The scale bars represent 100 μm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036866&req=5

pone.0163489.g003: Paraffin slides show normal microspore development in the partially rescued FIL-B.Microscopic images of anther transverse sections of Jing724 (A) and the partially rescued (B) and sterile (C) individuals of FIL-B. The black round microspores were considered as normal. The scale bars represent 100 μm.
Mentions: To test pollen development during the microspore stage in the anthers, we observed the anther dissection under a light microscope. However, the development differed in the sterile and partially rescued anthers during telophase of the uninucleate microspores (Fig 3). Although the development and structure of tapetum were the same in both genotypes, all of the microspores collapsed in the sterile anthers, while a small proportion of the microspores had normal development in the partially rescued plants. The individual normal microspores from the FIL-B partially rescued plants might lead to normal mature pollen, which is consistent with the pollen staining data and further confirms the fertility instability of FIL-B.

View Article: PubMed Central - PubMed

ABSTRACT

S-type cytoplasmic male sterility (CMS-S) is the largest group among the three major types of CMS in maize. CMS-S exhibits fertility instability as a partial fertility restoration in a specific nuclear genetic background, which impedes its commercial application in hybrid breeding programs. The fertility instability phenomenon of CMS-S is controlled by several minor quantitative trait locus (QTLs), but not the major nuclear fertility restorer (Rf3). However, the gene mapping of these minor QTLs and the molecular mechanism of the genetic modifications are still unclear. Using completely sterile and partially rescued plants of fertility instable line (FIL)-B, we performed bulk segregant RNA-Seq and identified six potential associated genes in minor effect QTLs contributing to fertility instability. Analyses demonstrate that these potential associated genes may be involved in biological processes, such as floral organ differentiation and development regulation, energy metabolism and carbohydrates biosynthesis, which results in a partial anther exsertion and pollen fertility restoration in the partially rescued plants. The single nucleotide polymorphisms (SNPs) identified in two potential associated genes were validated to be related to the fertility restoration phenotype by KASP marker assays. This novel knowledge contributes to the understanding of the molecular mechanism of the partial fertility restoration of CMS-S in maize and thus helps to guide the breeding programs.

No MeSH data available.


Related in: MedlinePlus