Type Of Male Sterility Research Articles

The mitochondrial genes orf113b and orf146 from Xinjiang wild rapeseed cause pollen abortion in alloplasmic male sterility

Nsa CMS, a type of cytoplasmic male sterility (CMS) in rapeseed, originates from the cross between Xinjiang wild rapeseed (Sinapis arvensis) and Xiangyou 15 (Brassica napus L.). Although this CMS variant shows promising applications, the factors contributing to its sterility and their underlying mechanisms remain unclear. To the best of our knowledge, we successfully assembled and analyzed the mitochondrial genome of 1258A (Nsa CMS) for the first time. This mitochondrial genome, spanning 263,010 bp, contains 91 genes, including 33 protein-coding and 36 orf genes. Our analysis identified a novel mitochondrial gene, orf113b, and a mutated, truncated gene, orf146, both likely linked to the sterility observed in 1258A. ORF113b and ORF146 were found to impede cell growth, disrupt gene expression associated with complexes I, III, and V of the mitochondrial oxidative phosphorylation pathway, and trigger reactive oxygen species (ROS) production. Additionally, transcriptome data analysis revealed key nuclear genes co-expressed with orf113b and orf146, suggesting that their aberrant expression may be influenced by retrograde signaling from the mitochondria. This signaling could lead to atypical programmed cell death (PCD) in the tapetum layer, resulting in pollen sterility. In conclusion, our study not only provides the first characterization of the Nsa CMS mitochondrial genome but also identifies orf113b and orf146 as crucial to pollen sterility. Furthermore, it suggests that ROS induced by these mitochondrial genes may play a central role in the abnormal regulation of nuclear genes essential for pollen development, offering new insights into the molecular mechanisms underlying Nsa CMS.

Mutations in nuclear genes encoding mitochondrial ribosome proteins restore pollen fertility in S male-sterile maize.

The interaction of plant mitochondrial and nuclear genetic systems is exemplified by mitochondria-encoded cytoplasmic male sterility (CMS) under the control of nuclear restorer-of-fertility genes. The S type of CMS in maize is characterized by a pollen collapse phenotype and a unique paradigm for fertility restoration in which numerous nuclear restorer-of-fertility lethal mutations rescue pollen function but condition homozygous-lethal seed phenotypes. Two nonallelic restorer mutations recovered from Mutator transposon-active lines were investigated to determine the mechanisms of pollen fertility restoration and seed lethality. Mu Illumina sequencing of transposon-flanking regions identified insertion alleles of nuclear genes encoding mitochondrial ribosomal proteins RPL6 and RPL14 as candidate restorer-of-fertility lethal mutations. Both candidates were associated with lowered abundance of mitochondria-encoded proteins in developing maize pollen, and the rpl14 mutant candidate was confirmed by independent insertion alleles. While the restored pollen functioned despite reduced accumulation of mitochondrial respiratory proteins, normal-cytoplasm plants heterozygous for the mutant alleles showed a significant pollen transmission bias in favor of the nonmutant Rpl6 and Rpl14 alleles. CMS-S fertility restoration affords a unique forward genetic approach to investigate the mitochondrial requirements for, and contributions to, pollen and seed development.

Marker assisted selection reveal SNP deletion mutation in gene associated with cytoplasmic male sterility in Solanumvillosum

Male sterility (MS) is powerful tool for improvement of various traits of economic importance. MS has not been characterized in Solanum villosum, and molecular mechanism underlying mutation change have not yet been studied. In this study, Sanger sequence platform was employed to amplify the MS genic region using mt ATPase marker. The molecular mechanism governing sterility was studied, and the results detected the amplification region at 1150bp. The sequence query was 97 % identical with atp subunit 6 gene loci. Significance mutation detected in this study was deletion GG (delGG) and deletion C (delC) occurring between 536bp and 542bp position in atp6 gene transcript. The mutation score was 16 for delGG and 17 for delC, with a 90 % mutation confidence interval. The study observed that SNP changes due to base deletions in the atp6 gene region were the main cause of male sterility in the studied mutants due to anticipated frameshifts of the open reading frame (ORF) of the mitochondrial atp6 gene, this is regarded as cytoplasmic male sterility type (CMS). Deformed and low pollen count was morphological changes confirmed this study that associated with sterility. Disruption of the ATP synthesis in mitochondria, limits the energy supply for pollen grain formation and anticipated pollen sterility however, mitochondria nuclear gene interaction governing the CMS should be further studied in case of S.villosum. These findings shed-light on molecular mechanism underlying the CMS and can be utilized as a molecular marker for agronomic traits improvement of S.villosum.

ORF138 causes abnormal lipid metabolism in the tapetum leading to Ogu cytoplasmic male sterility in Brassica napus

Plant cytoplasmic male sterility is caused by mutations and rearrangements of mitochondrial genes. It serves as a significant way to utilize hybrid vigor to enhance crop yield. Ogu CMS is a natural cytoplasmic male sterility type discovered in radishes, being successfully transferred to rapeseed and cruciferous vegetables. However, current studies lack depth in exploring the molecular mechanisms of its male sterility. In this study, we confirmed orf138 is the causal gene for Ogu CMS through genetic transformation in Arabidopsis. Transcriptome analysis of aborted anthers in different stages suggested differentially expressed genes (DEGs) are mainly enriched in pathways such as glycerophospholipid metabolism and arginine and proline metabolism. It reveals that key genes involved in lipid metabolism pathways are significantly down-regulated in the sterile line (OguA), including BnaGPAT1, localized within the tapetum mitochondrial and endoplasmic reticulum. This could lead to changes in the metabolism of substances like acylglycerols within the tapetum, causing disruptions in lipid metabolism. This is consistent with morphological and subcellular structural changes in the tapetum and microspore cells as observed in the transmission electron microscopy. This abnormal lipid metabolism may trigger specific ROS accumulation in an oxidative stress response, ultimately leading to aborted microspore. Our study based on transcriptome has deepened our understanding of the molecular mechanisms in Ogu CMS.

Correlation between the response of maize lines to CMS and their origin

Transferring maize hybrids to a sterile basis is the most important condition for their introduction into production. In this regard, it is important to study the behavior of the initial forms of hybrids, namely self-pollinated lines, in the sterile cytoplasm. The purpose of the current study was to estimate the response of new self-pollinated maize lines, depending on their origin, to the “M” and “C” types of CMS, to identify natural restoring agents and complete sterility fixatives. The study was carried out at the FSBSI “ARC “Donskoy” in 2021–2023. The subjects of the study were 20 new self-pollinated maize lines of various origins, 6 sources of sterility, 120 testcross maize hybrids. There was found that the response of maize lines depended on their origin. Lines belonging to the same group (by origin) usually had the same reaction to the Moldovan (“M”) and Bolivian (“C”) types of cytoplasmic male sterility (CMS). The closer the lines are related, the smaller the differences. The new self-pollinated lines of the first group ‘SL 171’, ‘SL 172’, ‘SL 174’, ‘SL 175’, ‘SL 176’ and ‘SL 177’ were characterized by complete consolidation of the type “M” of CMS (class 0). Lines of subgroup Ia were fixed, but subgroups Ib did not completely restore the type “C” of sterility. In the second group there were identified the complete ‘SL 181’, ‘SL 182’ (class 4, 5) and incomplete ‘SL 183’, ‘SL 184’ (class 2–5) reducing agents of the type “M” of sterility. There was determined that all lines of the second group perpetuated sterility of the Bolivian type (class 0). There have been identified the lines of the third group ‘SL 191’, ‘SL 192’, ‘SL 193’, ‘SL 194’, as full reducing agents of the type “M” of CMS, two of them ‘SL 191’ and ‘SL 193’ are also complete reducing agents of the type “C” of CMS (class 4, 5). All lines of the fourth group could be classified as complete fixatives (class 0, 1) of the studied types of CMS. The results obtained will improve the efficiency of work on transferring maize hybrids to a sterile basis.

The top Bulgarian contributions to sunflower breeding

Abstract The sunflower (Helianthus annuus L.) is a fundamental oil-yielding culture for Bulgaria and the world and thus, special attention is paid to it. Various selection methods have been used over the years and as a result of successful breeding programs new sunflower forms, lines (В/А and R) and hybrids (oil and confectionery type) were created in Bulgaria. Some of these new forms have new plant architectonic, different vegetation periods, seeds with different sizes and coloration, high combining ability, resistance to diseases, the parasite Broomrape and some herbicides, high seed oil and fatty acid content, genes for restoration of fertility (Rf genes), and different types of cytoplasmic male sterility (CMS).

Floral morphology of 'Anand' rapid cycling Brassica oleracea .

Abstract The 'Anand' type of cytoplasmic male sterility (CMS) was introduced to Brassica oleracea through protoplast fusion (Cardi and Earle, 1997), providing a source of male sterility that is of value in producing F1 hybrid varieties of this species without the cold sensitivity of 'Ogura' cytoplasm. In this species, as in others in which it has been introduced, 'Anand' mitochondria are associated with flower abnormalities. The best lines have been used by commercial breeders. This paper describes 'Anand' flower abnormalities in further detail. Rapid cycling brassica with 'Anand' cytoplasm may have promise as a model system for research on floral patterning. Materials and Methods. Three lines of rapid cycling B. oleracea carrying the 'Anand' cytoplasm and one wild type were grown. The flower morphology of 'Anand' lines was classified as good in F25-F-1A, fair in F25-F-6B, and poor in F23-F-1B (Cardi and Earle, 1997). Seedlings were started in an indoor growth room, but were maintained in a naturally lit greenhouse at 20° night, 25° day during flowering. Five flowers on 5 plants of each line were examined. Results. Morphological abnormalities affected all floral parts (Table 1). There was substantial variation among flowers on individual plants and among lines but little within lines. Conclusions. "Good" flowers have large petals that push open the sepals before the carpel elongates. Female fertility could be reduced due to occlusion of the stigma or physical damage caused by the stigma pressing against the end of a sepal and kinking the style. Female fertility in some flowers was unlikely because the carpel suture failed to fuse. In some cases the edge of the split carpel was sepal-like, consistent with the absence of SEPALLATA expression. The stigma on a sepal represents the converse. Stamens were most strongly affected, with outer stamens most reduced. This whorl is the one most frequently suppressed in flowering plants (Masters, 1869). The number of stamens was reduced to varying degrees. First to be lost was one or both of the pair outside the petals. Then the outer pair inside the petals was affected. One or both of these stamens could either be lost or doubled to give 3 to 5 stamens. Again a positional cue for stamens appears to be weakened. Anther development was often limited, the expected and desired consequence of the Anand genotype. Some undehisced " good " anthers contained pollen. There is variation even among the lines initially described as " good ". Further selection among these may help identify those that are most promising for further use in hybrid production.

Selection of inbreds with better combining ability is instrumental in developing CMS-based heterotic hybrids in tropical carrot (Daucus carota L.)

Abstract Carrot is an important vegetable crop worldwide valued for its fleshy edible roots of varied colours. Owing to its highly cross-pollinated nature and small flower size, cytoplasmic male sterility (CMS) is being utilized for hybrid development. Among different types of male sterility, petaloid CMS is widely used for hybrid carrot breeding globally. This study aimed to develop selection criteria for parents in developing heterotic F1 hybrids using CMS lines. A large number of agro-morphological traits and Simple Sequence Repeats (genomic-SSRs) were used to assess the diversity among parental lines. We developed 60 F1 hybrids by crossing four petaloid CMS lines and 15 testers in line × tester mating design and evaluated them in replicated randomized block design trial for four vegetative and 11 economic traits. The mean squares of all the traits in line × tester interactions were significant. The estimates of genetic components of variance indicated predominance of non-additive gene action except for root maturity, root length and core diameter. The hybrids with highest per se performance also had significant positive specific combining ability effects. The root yield and root weight showed highest heterosis percentage (33%). The best performing heterotic hybrids were DCatH-5392, DCatH-700 and DCatH-9892. Correlation between genetic distance and relative heterosis of economic traits indicated no significant association and thus genetic distance could not be used to predict heterosis. As most of the yield-related traits were controlled by non-additive gene action, heterosis breeding could be potentially used along with combining ability analysis to reduce time in selection of best parents and crosses in tropical carrot.

A review of rice male sterility types and their sterility mechanisms

Male sterility plays an important role in the utilization of heterosis in rice. The establishment of male sterile lines in rice is one of the key technologies in hybrid rice production systems. The currently widely used male sterile line breeding systems mainly include: three-line hybrid rice based on cytoplasmic male sterility, two-line hybrid rice based on environmental sensitive gene male sterility, and third-generation hybrid rice based on nuclear gene male sterility Seed production system. This study reviewed the types and mechanisms of male sterility in rice, and looked forward to the development direction of hybrid rice.

Induce male sterility by CRISPR/Cas9-mediated mitochondrial genome editing in tobacco.

Genome editing has become more and more popular in animal and plant systems following the emergence of CRISPR/Cas9 technology. However, target sequence modification by CRISPR/Cas9 has not been reported in the plant mitochondrial genome, mtDNA. In plants, a type of male sterility known as cytoplasmic male sterility (CMS) has been associated with certain mitochondrial genes, but few genes have been confirmed by direct mitochondrial gene-targeted modifications. Here, the CMS-associated gene (mtatp9) in tobacco was cleaved using mitoCRISPR/Cas9 with a mitochondrial localization signal. The male-sterile mutant, with aborted stamens, exhibited only 70% of the mtDNA copy number of the wild type and exhibited an altered percentage of heteroplasmic mtatp9 alleles; otherwise, the seed setting rate of the mutant flowers was zero. Transcriptomic analyses showed that glycolysis, tricarboxylic acid cycle metabolism and the oxidative phosphorylation pathway, which are all related to aerobic respiration, were inhibited in stamens of the male-sterile gene-edited mutant. In addition, overexpression of the synonymous mutations dsmtatp9 could restore fertility to the male-sterile mutant. Our results strongly suggest that mutation of mtatp9 causes CMS and that mitoCRISPR/Cas9 can be used to modify the mitochondrial genome of plants.

Environment-sensitive genic male sterility in rice and other plants.

Environment-sensitive genic male sterility is a type of male sterility that is affected by both genetic and environmental factors. Environment-sensitive genic male sterile lines are not only used in two-line hybrid breeding but are also good materials for studying plant-environment interactions. In this study we review the research progress on environment-sensitive genic male sterility in rice from the perspectives of epigenetic, transcriptional, posttranscriptional, posttranslationaland metabolic mechanisms as well as signal transduction processes. While significant progress has been made in the genetics, gene cloningand understanding of the molecular mechanisms of environment-sensitive genic male sterility in recent years, the relevant regulatory network is still poorly understood in rice. We therefore also review studies of environment-sensitive genic male sterility in Arabidopsis and other crops, hoping to promote research in this field in rice. Finally, we analyse the challenges posed by environment-sensitive genic male sterility and provide corresponding suggestions. This review will contribute towards an understanding the molecular genetics of environment-sensitive genic male sterility and its application in two-line hybrid breeding in rice and other species.

Genic male and female sterility in vegetable crops.

Vegetable crops are greatly appreciated for their beneficial nutritional and health components. Hybrid seeds are widely used in vegetable crops for advantages such as high yield and improved resistance, which require the participation of male (stamen) and female (pistil) reproductive organs. Male- or female-sterile plants are commonly used for production of hybrid seeds or seedless fruits in vegetables. In this review we will focus on the types of genic male sterility and factors affecting female fertility, summarize typical gene function and research progress related to reproductive organ identity and sporophyte and gametophyte development in vegetable crops [mainly tomato (Solanum lycopersicum) and cucumber (Cucumis sativus)], and discuss the research trends and application perspectives of the sterile trait in vegetable breeding and hybrid production, in order to provide a reference for fertility-related germplasm innovation.

The 4R QTLs pollen fertility restoration in triticale with CMS Triticum timopheevii

AbstractThe Triticum timopheevii Zhuk. (Tt) cytoplasm is the most exploited cytoplasmic male sterility (CMS) type used in triticale in commercial seed production of hybrid varieties. The present study established a recombinant inbred line (RIL) mapping population to identify genetic loci controlling fertility restoration in triticale with CMS Tt. The trait was evaluated via phenotyping the BC1F1 materials originating from a backcross of maternal line MS 112(15)‐2‐1 (on CMS Tt) and RILs. A genetic map spanning 2293 cM over 21 linkage groups was constructed using 1,170 single nucleotide polymorphisms and silico diversity array technology (DArT) markers generated through DArTseq genotyping. Two quantitative trait loci (QTL) controlling fertility restoration were localized at the 4RL chromosome. They were stable during two vegetative seasons and, depending on the year, explained 17.8 to 37.5 (QRft‐4R.1) and 17.8 to 27.1% (QRft‐4R.2) of phenotypic variance. Bioinformatic analysis was performed to predict genes potentially responsible for the trait. Four markers linked to the trait were successfully converted into a polymerase chain reaction‐based assay to select the pollen fertility QTLs easily. The exact position of QTLs detected previously in the rye and here in the triticale suggests that the same loci might control the trait.

Developmentally regulated mitochondrial biogenesis and cell death competence in maize pollen

BackgroundCytoplasmic male sterility (CMS) is a maternally inherited failure to produce functional pollen that most commonly results from expression of novel, chimeric mitochondrial genes. In Zea mays, cytoplasmic male sterility type S (CMS-S) is characterized by the collapse of immature, bi-cellular pollen. Molecular and cellular features of developing CMS-S and normal (N) cytoplasm pollen were compared to determine the role of mitochondria in these differing developmental fates.ResultsTerminal deoxynucleotidyl transferase dUTP nick end labeling revealed both chromatin and nuclear fragmentation in the collapsed CMS-S pollen, demonstrating a programmed cell death (PCD) event sharing morphological features with mitochondria-signaled apoptosis in animals. Maize plants expressing mitochondria-targeted green fluorescent protein (GFP) demonstrated dynamic changes in mitochondrial morphology and association with actin filaments through the course of N-cytoplasm pollen development, whereas mitochondrial targeting of GFP was lost and actin filaments were disorganized in developing CMS-S pollen. Immunoblotting revealed significant developmental regulation of mitochondrial biogenesis in both CMS-S and N mito-types. Nuclear and mitochondrial genome encoded components of the cytochrome respiratory pathway and ATP synthase were of low abundance at the microspore stage, but microspores accumulated abundant nuclear-encoded alternative oxidase (AOX). Cytochrome pathway and ATP synthase components accumulated whereas AOX levels declined during the maturation of N bi-cellular pollen. Increased abundance of cytochrome pathway components and declining AOX also characterized collapsed CMS-S pollen. The accumulation and robust RNA editing of mitochondrial transcripts implicated translational or post-translational control for the developmentally regulated accumulation of mitochondria-encoded proteins in both mito-types.ConclusionsCMS-S pollen collapse is a PCD event coincident with developmentally programmed mitochondrial events including the accumulation of mitochondrial respiratory proteins and declining protection against mitochondrial generation of reactive oxygen species.

Characterization, inheritance of male sterility and development of male sterile and maintainer lines in ridge gourd (Luffa acutangula (Roxb.) L.)

Two male sterile mutants IIHRRG-12MS (long fruited) and IIHRRG-28MS (medium long fruited) were identified from the ridge gourd germplasm IIHR-12 and IIHR-28 respectively at ICAR-IIHR, Bengaluru. These two male-sterile (ms) sources were characterized by the production of rudimentary male flowers in the racemes in contrast to the bright yellow flowers with fertile pollen and healthy anthers in male fertile, monoecious plants. Using these ms lines the inheritance of male sterility was worked out, which is cytoplasmic genic male sterility (CGMS) type, with single dominant gene either in homozygous or heterozygous condition restoring male fertility in the presence of sterile cytoplasm. In order to develop F1 hybrids using male sterility, several male sterile and maintainer lines were developed in different genetic back grounds such as green/dark green fruit colour and short/medium long/long fruit length.

The CinB Nuclease from wNo Wolbachia Is Sufficient for Induction of Cytoplasmic Incompatibility in Drosophila.

ABSTRACTWolbachia is an obligate intracellular bacterium that can alter reproduction of its arthropod hosts, often through a mechanism called cytoplasmic incompatibility (CI). In CI, uninfected females fertilized by infected males yield few offspring, but if both are similarly infected, normal embryo viability results (called “rescue”). CI factors (Cifs) responsible for CI are pairs of proteins encoded by linked genes. The downstream gene in each pair encodes either a deubiquitylase (CidB) or a nuclease (CinB). The upstream gene products, CidA and CinA, bind their cognate enzymes with high specificity. Expression of CidB or CinB in yeast inhibits growth, but growth is rescued by expression of the cognate CifA protein. By contrast, transgenic Drosophila male germ line expression of both cifA and cifB was reported to be necessary to induce CI-like embryonic arrest; cifA expression alone in females is sufficient for rescue. This pattern, seen with genes from several Wolbachia strains, has been called the “2-by-1” model. Here, we show that male germ line expression of the cinB gene alone, from a distinct clade of cif genes from wNo Wolbachia, is sufficient to induce nearly complete loss of embryo viability. This male sterility is fully rescued by cognate cinAwNo expression in the female germ line. The proteins behave similarly in yeast. CinBwNo toxicity depends on its nuclease active site. These results demonstrate that highly divergent CinB nucleases can induce CI, that rescue by cognate CifA factors is a general feature of Wolbachia CI systems, and that CifA is not strictly required in males for CI induction.

SSR-маркеры, ассоциированные с геном-восстановителем ЦМС 9Е сорго

9E type of cytoplasmic male sterility (CMS) in sorghum belongs to environmentally-regulated types of male sterility in which the restoration of fertility is regulated, along with the genotype, by plant water availability and air humidity on the eve and during the flowering period. For studying the genetic control and understanding the mechanisms of epigenetic processes that regulate the restoration of fertility in this CMS type, the identification of fertility restoring genes (Rf-9E) is extremely important. To solve this problem, we carried out the work on identification of molecular markers associated with the Rf-9E genes. For this purpose, we used the plants of the BC1 population [(9E Pishchevoe 614 × 84/19) × Pishchevoe 614] segregated for fertility restoration. In total, 55 SSR markers were used, mapping all 10 chromosomes of the sorghum genome. It was found that SSR markers located on chromosome 2 of the sorghum genome, sam60498 (23911554…23913675 bp) and sam37585 (33055782…33056867 bp), demonstrate a significant association with the restoration of male fertility in the studied population. In silico analysis of the reference genome of S. bicolor (BTx623) showed that near this region, which includes more than 9 million bp, there are a pericentromeric heterochromatin region, and two PPR genes, 002G142700.1 and 002G144300.1 located at 23465796…23468350 bp and 23810047…23812824bp, respectively. Given that the vast majority of cloned Rf-genes in various plant species, including sorghum, contain sequences of PPR genes, the SSR markers identified in this study can indeed be the molecular markers of 9ECMS fertility-restoring genes. A hypothesis on the relationship between the localization of CMS 9E fertility-restoring genes near heterochromatin and the “moisture-dependent” nature of male fertility restoration in this CMS type is discussed.

Перспективные экспериментальные гибриды рапса ярового (Brassica napus L.), созданные с использованием системы ЦМС типа Polima

One of the prior directions in spring rapeseed breeding is development of heterotic hybrids. Seed growing of the most hybrids F1 used in production are often carried out by two types of cytoplasmic male sterility, they are polima and ogura. At the Lipetsk Rapeseed Research Institute, fertility restorers on sterile cytoplasm were made and estimated for the main valuable traits. The purpose of the research was to develop effective restorers, which are necessary for obtaining of highly productive hybrids on the Polima type cytoplasmic male sterility (CMS). The object of research was 56 varieties of Brassica napus L., which were selected in 2013. It is noted that hybrids F1 were more productive than the parental forms and the standards (the varieties Ratnik and Rif). The restorer line LHR-1 is of practical interest for the development of hybrids on the Polima CMS.

Поиск восстановителей фертильности для системы ЦМС типа Polima рапса ярового (Brassica napus L.) и оценка их качества

One of the prior directions in modern rapeseed breeding is making heterotic hybrids. Seed production of most hybrids F1 used in production are often carried out by two types of cytoplasmic male sterility, there are Polima and Ogura. At the All-Russian Rapeseed Research Institute, fertility restorers on sterile cytoplasm were made and estimated for the main valuable characteristics and biochemical properties. The purpose of the study was to create reducing agents necessary for obtaining highly productive hybrids on the Polima type cytoplasmic male sterility (CMS). The object of research was 56 varieties of Brassica napus L., which were chosen in 2013. The setting of experiments, observations, records and analyzes were carried out using the field plot technique, the methodology of field experiments, the method of statistical data processing. It is noted that hybrids F1 had more productivity than the parental forms and the standard (Ratnik and Rif). Promising reducing agents of cytoplasmic male sterility of the Polima type were identified, which ensured complete restoration of fertility in sterile lines with CMS of the Polima type. The reducing agent LHR-1 is of practical interest for the creation of hybrids on the Polima CMS.

High-generation near-isogenic lines combined with multi-omics to study the mechanism of polima cytoplasmic male sterility

BackgroundCytoplasmic male sterility (CMS), which naturally exists in higher plants, is a useful mechanism for analyzing nuclear and mitochondrial genome functions and identifying the role of mitochondrial genes in the plant growth and development. Polima (pol) CMS is the most universally valued male sterility type in oil-seed rape. Previous studies have described the pol CMS restorer gene Rfp and the sterility-inducing gene orf224 in oil-seed rape, located in mitochondria. However, the mechanism of fertility restoration and infertility remains unknown. Moreover, it is still unknown how the fecundity restorer gene interferes with the sterility gene, provokes the sterility gene to lose its function, and leads to fertility restoration.ResultIn this study, we used multi-omics joint analysis to discover candidate genes that interact with the sterility gene orf224 and the restorer gene Rfp of pol CMS to provide theoretical support for the occurrence and restoration mechanisms of sterility. Via multi-omics analysis, we screened 24 differential genes encoding proteins related to RNA editing, respiratory electron transport chain, anther development, energy transport, tapetum development, and oxidative phosphorylation. Using a yeast two-hybrid assay, we obtained a total of seven Rfp interaction proteins, with orf224 protein covering five interaction proteins.ConclusionsWe propose that Rfp and its interacting protein cleave the transcript of atp6/orf224, causing the infertility gene to lose its function and restore fertility. When Rfp is not cleaved, orf224 poisons the tapetum cells and anther development-related proteins, resulting in pol CMS mitochondrial dysfunction and male infertility. The data from the joint analysis of multiple omics provided information on pol CMS’s potential molecular mechanism and will help breed B. napus hybrids.