The restorer gene for soybean M‐type cytoplasmic male sterility, Rf‐m, is located in a PPR gene‐rich region on chromosome 16

Abstract

Over the past decade, M-type cytoplasmic male sterility (CMS) line W931A and a variety of restorer lines have been exploited for the release of hybrid seeds in soybean (Glycine max). However, the identities of restorer genes in the nuclei of soybean restorer lines are still unclear. In this study, we analysed the inheritance pattern of restorer locus Rf-m from restorer line WR016 and constructed a high-resolution map of this locus. Results showed that Rf-m in WR016 is a monogenic dominant gene located within a 162.4-kb region on chromosome 16, which is flanked on each side by new developed simple sequence repeat (SSR) markers GmSSR1602 and GmSSR1610 at a distance of 0.11 and 0.25 cM, respectively. Nineteen open reading frames (ORFs) were predicted in this region. Of these, seven genes arranged in tandem on chromosome 16 encode pentatricopeptide repeat (PPR) proteins, which is similar to other reported restorer loci in plants. These results lay a solid foundation for map-based cloning of the Rf-m gene and will be helpful for marker-assisted selection of elite CMS restorer lines.Key words: soybean line W931A -simple sequence repeat marker -restorer line WR016 -mapping Cytoplasmic male sterility (CMS) is a maternally inherited trait that results in the inability of plants to produce fertile pollen (Hanson and Bentolila 2004). CMS is often associated with variations in the mitochondrial genome (Mackenzie et al. 1994, Schnable and Wise 1998, St€ adler and Delph 2002. In previous studies, male sterility can be restored by introducing some dominant nuclear genes, which are referred to as Rf (restorer of fertility) genes (Budar and Pelletier 2001, Liu et al. 2001). The CMS/Rf system is an ideal model for studying genetic interactions between the nuclear and mitochondrial genomes of plants. Additionally, the CMS/Rf system is also a practical tool for hybrid seed production (Liu et al. 2012). In China, several soybean hybrids developed using the CMS/Rf system have been released. The yields of these hybrids are 15-20% higher than those of the corresponding inbred parental varieties (Zhao et al. 2004, Zhang et al. 2007a, Peng et al. 2008.Soybean CMS lines in China are mainly gametophytic male sterile. These lines are classified into five main types based on the origin of the sterile cytoplasm: M, RN, ZD, XX and N8855 (Zhang et al. 1999, Ding et al. 2002, Sun et al. 2003. Among them, M-type CMS lines were developed using a local earlymaturing cultivar, 'Zhongyou89B', as the cytoplasm donor (Zhang et al. 1999(Zhang et al. , 2007b. Zhang et al. (1999) reported that W931A, which belongs to the class of M-type, produces~98.7% aborted pollen and exhibits a number of beneficial traits for breeding, such as stable sterility, strong combining ability and wide adaptability. The first summer soybean hybrid in the early maturity group to be released was developed using this line, with an average yield increase of 19.14% (Zhang et al. 2007a). One challenge encountered when using CMS for breeding is identifying a good restorer lin...

Exploration of miRNA-mediated fertility regulation network of cytoplasmic male sterility during flower bud development in soybean

“…PPR proteins are classified as Rf proteins that suppress CMS gene expression through posttranscriptional mechanisms such as editing, cleavage, and degradation of the target mRNAs in many plants such as rice, Brassica, radish, and sorghum (Chen et al 2014; Brown et al 2003; Hu et al 2012; Iwabuchi et al 1999; Jordan et al 2010; Kazama et al 2003). Recently, Wang et al (2016a) identified the Rf gene for soybean M-type CMS, Rf-m, which is located in a PPR gene-rich region on chromosome 16. This region contains 19 putative open reading frames (ORFs), and seven of them encode putative PPR proteins.…”

Harnessing heterosis and male sterility in soybean [Glycine max (L.) Merrill]: A critical revisit

“…A total of 94 sterile mutants were identified and three-line system-based CMS was also developed ( Ray et al, 2003 ; Palmer et al, 2012 ; Zhao et al, 2019 ; Nadeem et al, 2021 ). Along with these, three CMS restorer loci and two independent locus Rf-m were fine-mapped ( Wang et al, 2016 ; Zhao et al, 2019 ). Similarly, genes related to NMS have also been identified in soybean.…”

Male sterility in soybean: Occurrence, molecular basis and utilization

“…Three SSR markers, Satt684, Satt276 and Satt545 on LG “A1” linked to the rf ‐gene of M‐type CMS line (W931A), were obtained, and their genetic distances were 29.5, 10.7 and 14.1 cM, respectively (Tang, Zhang, Chen, Chen, & Liang, ). Further, Wang et al () mapped Rf ‐m located in a ~160‐kb region on LG “J”, a restorer gene from M‐type CMS lines, which was flanked on each side by GmSSR1602 and GmSSR1610 at a distance of 0.11 and 0.25 cM, respectively. Additionally to this, Wang et al () found that Satt215, Sctt011 and Satt547 on LG “J” linked to the rf ‐gene of JLCMS82A.…”