Anther and pollen development in male-sterile intermediate wheatgrass plants derived from wheat × wheatgrass hybrids

1979 ◽  
Vol 57 (6) ◽  
pp. 602-618 ◽  
Author(s):  
B. A. Young ◽  
J. Schulz-Schaeffer ◽  
T. W. Carroll

Several different expressions of male sterility were observed in the plants sampled for the study of pollen and anther development in the third substitution backcross generation to intermediate wheatgrass. These included (1) pollen abortion following engorgement with starch, (2) abortion of microspores with exine abnormalities (found most often in plants with a high degree of meiotic irregularities), (3) abortion of microspores with normal exines, (4) release at anther dehiscence of normal-appearing late vacuolate microspores, (5) enlargement of one of the parietal layers of the anther, and (6) tapetal abnormalities, including orbicular wall malformations. Anthers from plants which were male sterile or partially male sterile and meiotically irregular were shorter than anthers from fertile or partially male-sterile, meiotically regular plants.Definite statements about specific causes of the male sterility could not be made. Meiotic irregularities may be involved in some of the male sterility, and exine malformations appeared to be directly related to sterile microspores. Tapetal disturbances were observed infrequently. Probably the consequences of several factors were observed in the backcross material.


2019 ◽  
Vol 20 (24) ◽  
pp. 6252 ◽  
Author(s):  
Junchang Li ◽  
Jing Zhang ◽  
Huijuan Li ◽  
Hao Niu ◽  
Qiaoqiao Xu ◽  
...  

Male sterility is a valuable trait for genetic research and production application of wheat (Triticum aestivum L.). NWMS1, a novel typical genic male sterility mutant, was obtained from Shengnong 1, mutagenized with ethyl methane sulfonate (EMS). Microstructure and ultrastructure observations of the anthers and microspores indicated that the pollen abortion of NWMS1 started at the early uninucleate microspore stage. Pollen grain collapse, plasmolysis, and absent starch grains were the three typical characteristics of the abnormal microspores. The anther transcriptomes of NWMS1 and its wild type Shengnong 1 were compared at the early anther development stage, pollen mother cell meiotic stage, and binucleate microspore stage. Several biological pathways clearly involved in abnormal anther development were identified, including protein processing in endoplasmic reticulum, starch and sucrose metabolism, lipid metabolism, and plant hormone signal transduction. There were 20 key genes involved in the abnormal anther development, screened out by weighted gene co-expression network analysis (WGCNA), including SKP1B, BIP5, KCS11, ADH3, BGLU6, and TIFY10B. The results indicated that the defect in starch and sucrose metabolism was the most important factor causing male sterility in NWMS1. Based on the experimental data, a primary molecular regulation model of abnormal anther and pollen developments in mutant NWMS1 was established. These results laid a solid foundation for further research on the molecular mechanism of wheat male sterility.



2021 ◽  
Vol 12 ◽  
Author(s):  
Miaomiao Hao ◽  
Wenlong Yang ◽  
Tingdong Li ◽  
Muhammad Shoaib ◽  
Jiazhu Sun ◽  
...  

Cytoplasmic male sterility (CMS) plays an essential role in hybrid seeds production. In wheat, orf279 was reported as a CMS gene of AL-type male sterile line (AL18A), but its sterility mechanism is still unclear. Therefore, transcriptomic and proteomic analyses of the anthers of AL18A and its maintainer line (AL18B) were performed to interpret the sterility mechanism. Results showed that the electron transport chain and ROS scavenging enzyme expression levels changed in the early stages of the anther development. Biological processes, i.e., fatty acid synthesis, lipid transport, and polysaccharide metabolism, were abnormal, resulting in pollen abortion in AL18A. In addition, we identified several critical regulatory genes related to anther development through combined analysis of transcriptome and proteome. Most of the genes were enzymes or transcription factors, and 63 were partially homologous to the reported genic male sterile (GMS) genes. This study provides a new perspective of the sterility mechanism of AL18A and lays a foundation to study the functional genes of anther development.



Author(s):  
Junping Yu ◽  
Guolong Zhao ◽  
Wei Li ◽  
Ying Zhang ◽  
Peng Wang ◽  
...  

Abstract Key message Identification and functional analysis of the male sterile gene MS6 in Glycine max. Abstract Soybean (Glycine max (L.) Merr.) is an important crop providing vegetable oil and protein. The male sterility-based hybrid breeding is a promising method for improving soybean yield to meet the globally growing demand. In this research, we identified a soybean genic male sterile locus, MS6, by combining the bulked segregant analysis sequencing method and the map-based cloning technology. MS6, highly expressed in anther, encodes an R2R3 MYB transcription factor (GmTDF1-1) that is homologous to Tapetal Development and Function 1, a key factor for anther development in Arabidopsis and rice. In male sterile ms6 (Ames1), the mutant allele contains a missense mutation, leading to the 76th leucine substituted by histidine in the DNA binding domain of GmTDF1-1. The expression of soybean MS6 under the control of the AtTDF1 promoter could rescue the male sterility of attdf1 but ms6 could not. Additionally, ms6 overexpression in wild-type Arabidopsis did not affect anther development. These results evidence that GmTDF1-1 is a functional TDF1 homolog and L76H disrupts its function. Notably, GmTDF1-1 shows 92% sequence identity with another soybean protein termed as GmTDF1-2, whose active expression also restored the fertility of attdf1. However, GmTDF1-2 is constitutively expressed at a very low level in soybean, and therefore, not able to compensate for the MS6 deficiency. Analysis of the TDF1-involved anther development regulatory pathway showed that expressions of the genes downstream of TDF1 are significantly suppressed in ms6, unveiling that GmTDF1-1 is a core transcription factor regulating soybean anther development.



2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yanyan Sun ◽  
Dongsuo Zhang ◽  
Zhenzhen Wang ◽  
Yuan Guo ◽  
Xiaomin Sun ◽  
...  

Abstract Background Photoperiod and/or thermo-sensitive male sterility is an effective pollination control system in crop two-line hybrid breeding. We previously discovered the spontaneous mutation of a partially male sterile plant and developed a thermo-sensitive genic male sterile (TGMS) line 373S in Brassica napus L. The present study characterized this TGMS line through cytological observation, photoperiod/ temperature treatments, and genetic investigation. Results Microscopic observation revealed that the condensed cytoplasm and irregular exine of microspores and the abnormal degradation of tapetum are related to pollen abortion. Different temperature and photoperiod treatments in field and growth cabinet conditions indicated that the fertility alteration of 373S was mainly caused by temperature changes. The effects of photoperiod and interaction between temperature and photoperiod were insignificant. The critical temperature leading to fertility alteration ranged from 10 °C (15 °C/5 °C) to 12 °C (17 °C/7 °C), and the temperature-responding stage was coincident with anther development from pollen mother cell formation to meiosis stages. Genetic analysis indicated that the TGMS trait in 373S was controlled by one pair of genes, with male sterility as the recessive. Multiplex PCR analysis revealed that the cytoplasm of 373S is pol type. Conclusions Our study suggested that the 373S line in B. napus has a novel thermo-sensitive gene Bnmst1 in Pol CMS cytoplasm background, and its fertility alteration is mainly caused by temperature changes. Our results will broaden the TGMS resources and lay the foundation for two-line hybrid breeding in B. napus.



BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jian Wang ◽  
Yitao Yang ◽  
Lei Zhang ◽  
Shaoxing Wang ◽  
Lingyun Yuan ◽  
...  

Abstract Background The discovery of male sterile materials is of great significance for the development of plant fertility research. Wucai (Brassica campestris L. ssp. chinensis var. rosularis Tsen) is a variety of non-heading Chinese cabbage. There are few studies on the male sterility of wucai, and the mechanism of male sterility is not clear. In this study, the male sterile mutant MS7–2 and the wild-type fertile plant MF7–2 were studied. Results Phenotypic characteristics and cytological analysis showed that MS7–2 abortion occurred at the tetrad period. The content of related sugars in the flower buds of MS7–2 was significantly lower than that of MF7–2, and a large amount of reactive oxygen species (ROS) was accumulated. Through transcriptome sequencing of MS7–2 and MF7–2 flower buds at three different developmental stages (a–c), 2865, 3847, and 4981 differentially expressed genes were identified in MS7–2 at the flower bud development stage, stage c, and stage e, respectively, compared with MF7–2. Many of these genes were enriched in carbohydrate metabolism, phenylpropanoid metabolism, and oxidative phosphorylation, and most of them were down-regulated in MS7–2. The down-regulation of genes involved in carbohydrate and secondary metabolite synthesis as well as the accumulation of ROS in MS7–2 led to pollen abortion in MS7–2. Conclusions This study helps elucidate the mechanism of anther abortion in wucai, providing a basis for further research on the molecular regulatory mechanisms of male sterility and the screening and cloning of key genes in wucai.



2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lijun Zhang ◽  
Mingchuan Ma ◽  
Lin Cui ◽  
Longlong Liu

Abstract Background Male sterility (MS) has important applications in hybrid seed production, and the abortion of anthers has been observed in many plant species. While most studies have focused on the genetic factors affecting male sterility, the dynamic gene expression patterns of pollen abortion in male sterile lines have not been fully elucidated. In addition, there is still no hybrid oat that is commercially planted due to the lack of a suitable system of male sterility for hybrid breeding. Results In this study, we cultivated a male sterile oat line and a near-isogenic line by crossbreeding to elucidate the expression patterns of genes that may be involved in sterility. The first reported CA male sterile (CAMS) oat line was used for cross-testing and hybridization experiments and was confirmed to exhibit a type of nuclear sterility controlled by recessive genes. Oat stamens of two lines were sampled at four different developmental stages separately. Paired-end RNA sequencing was performed for each sample and generated 252.84 Gb sequences. There were 295,462 unigenes annotated in public databases in all samples, and we compared the histological characteristics and transcriptomes of oat stamens from the two oat lines at different developmental stages. Our results demonstrate that the sterility of the male sterile oat line occurs in the early stage of stamen development and is primarily attributable to abnormal meiosis and the excessive accumulation of superoxide. Conclusions To the best of our knowledge, this study is the first to decipher the dynamic expression profiles of pollen abortion CAMS and CA male fertile (CAMF) oat lines, which may represent a valuable resource for further studies attempting to understand pollen abortion and anther development in oats.



2021 ◽  
Vol 12 ◽  
Author(s):  
Zhimin Wang ◽  
Chao Yuan ◽  
Shaowei Zhang ◽  
Shibing Tian ◽  
Qinglin Tang ◽  
...  

Anther indehiscence is an important form of functional male sterility that can facilitate the production of hybrid seeds. However, the molecular mechanisms of anther indehiscence-based male sterility in eggplant (Solanum melongena L.) have not been thoroughly explored. We performed transcriptome sequencing and real-time quantitative reverse transcription-PCR (qRT-PCR) assays to compare the fertile line (F142) and male sterile line (S12) eggplant. We identified 2,670 differentially expressed genes (DEGs) between lines. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified 31 DEGs related to hormone biosynthesis. We, therefore, measured phytohormone contents, such as jasmonic acid (JA), auxin (IAA), gibberellin (GA), and abscisic acid (ABA) in S12 and F142. There were differences in IAA, GA3, and ABA levels between S12 and F142, while JA levels were significantly lower in S12 than in F142. Five key genes in the JA signaling pathway were differentially expressed in S12 vs. F142. Of these, SmJAZ1 and SmJAR1 were significantly upregulated and SmDAD1, SmLOX, and SmCOI1 were downregulated in S12 vs. F142. Protein–protein interaction studies identified a direct interaction between SmDAD1 and SmLOX, while SmDAD1 failed to interact with SmJAR1, SmCOI1, and SmJAZ1. The data represent a valuable resource for further exploration of regulatory mechanisms underlying anther dehiscence in eggplant.



Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2700
Author(s):  
Manuela Krüger ◽  
Oushadee A. J. Abeyawardana ◽  
Claudia Krüger ◽  
Miloslav Juříček ◽  
Helena Štorchová

Cytoplasmic male sterility (CMS), encoded by the interacting mitochondrial and nuclear genes, causes pollen abortion or non-viability. CMS is widely used in agriculture and extensively studied in crops. Much less is known about CMS in wild species. We performed a comparative transcriptomic analysis of male sterile and fertile individuals of Silene vulgaris, a model plant for the study of gynodioecy, to reveal the genes responsible for pollen abortion in this species. We used RNA-seq datasets previously employed for the analysis of mitochondrial and plastid transcriptomes of female and hermaphrodite flower buds, making it possible to compare the transcriptomes derived from three genomes in the same RNA specimen. We assembled de novo transcriptomes for two haplotypes of S. vulgaris and identified differentially expressed genes between the females and hermaphrodites, associated with stress response or pollen development. The gene for alternative oxidase was downregulated in females. The genetic pathways controlling CMS in S. vulgaris are similar to those in crops. The high number of the differentially expressed nuclear genes contrasts with the uniformity of organellar transcriptomes across genders, which suggests these pathways are evolutionarily conserved and that selective mechanisms may shield organellar transcription against changes in the cytoplasmic transcriptome.



2018 ◽  
Author(s):  
Wympher Langstang ◽  
Eros Kharshiing ◽  
Nagulan Venugopal

AbstractGaultheria fragrantissima Wall. (Ericaceae) is a gynodioecious species having both hermaphrodite and male sterile plants. In this study, we present a comparative analysis of the different stages of anther development in naturally occuring hermaphrodite and male sterile populations of G. fragrantissima found in Meghalaya, India. While hermaphrodite flowers had well developed anther lobes, the male sterile flowers formed a white unorganized mass of tissues with a tuft of hairy outgrowth at the tip of the stamens. Histological analyses of progressive anther development in both the lines indicate an abnormal development of the sporogenous tissue in the developing anthers in the male steril line. While anther development in the hermaphrodite line was of the dicotyledonous type, the anthers of male sterile line showed progressive degradation of the sporogenous tissues and wall layers. Pollen development was also disrupted in male sterile line resulting in distorted pollen due to the irregular projection of exine wall. Our results suggest that premature degradation of the sporogenous tissues during anther development determines male sterility in G. fragrantissima.



PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12349
Author(s):  
Jianhua Chen ◽  
Hao Xu ◽  
Jian Zhang ◽  
Shengjun Dong ◽  
Quangang Liu ◽  
...  

Background The phenomenon of male sterility widely occurs in Prunus sibirica and has a serious negative impact on yield. We identified the key stage and cause of male sterility and found differentially expressed genes related to male sterility in Prunus sibirica, and we analyzed the expression pattern of these genes. This work aimed to provide valuable reference and theoretical basis for the study of reproductive development and the mechanisms of male sterility in Prunus sibirica. Method The microstructures of male sterile flower buds and male fertile flower buds were observed by paraffin section. Transcriptome sequencing was used to screen genes related to male sterility in Prunus sibirica. Quantitative real-time PCR analysis was performed to verify the transcriptome data. Results Anther development was divided into the sporogenous cell stage, tetrad stage, microspore stage, and pollen maturity stage. Compared with male fertile flower buds, in the microspore stage, the pollen sac wall tissue in the male sterile flower buds showed no signs of degeneration. In the pollen maturity stage, the tapetum and middle layer were not fully degraded, and anther development stopped. Therefore, the microspore stage was the key stage for anther abortion , and the pollen maturity stage was the post stage for anther abortion. A total of 4,108 differentially expressed genes were identified by transcriptome analysis. Among them, 1,899 were up-regulated, and 2,209 were down-regulated in the transcriptome of male sterile flower buds. We found that “protein kinase activity”, “apoptosis process”, “calcium binding”, “cell death”, “cytochrome c oxidase activity”, “aspartate peptidase activity”, “cysteine peptidase activity” and other biological pathways such as “starch and sucrose metabolism” and “proteasome” were closely related to male sterility in Prunus sibirica. A total of 331 key genes were preliminarily screened. Conclusion The occurrence of male sterility in Prunus sibirica involved many biological processes and metabolic pathways. According to the results of microstructure observations, related physiological indexes determination and transcriptome analysis, we reveal that the occurrence of male sterility in Prunus sibirica may be caused by abnormal metabolic processes such as the release of cytochrome c in the male sterile flower buds, the imbalance of the antioxidant system being destroyed, and the inability of macromolecular substances such as starch to be converted into soluble small molecules at the correct stage of reproductive development, resulting in energy loss. As a result, the tapetum cannot be fully degraded, thereby blocking anther development, which eventually led to the formation of male sterility.



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