scholarly journals Tetraketide α-pyrone reductases in sporopollenin synthesis pathway in Gerbera hybrida: diversification of the minor function

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Lingping Zhu ◽  
Teng Zhang ◽  
Teemu H. Teeri
Keyword(s):  
Pollen Development ◽  
Polyketide Synthase ◽  
Land Plant ◽  
Vital Role ◽  
Pollen Wall ◽  
Major Constituent ◽  
Minor Role ◽  
Male Sterile ◽  
Gerbera Hybrida ◽  
Secondary Role

AbstractThe structurally robust biopolymer sporopollenin is the major constituent of the exine layer of pollen wall and plays a vital role in plant reproductive success. The sporopollenin precursors are synthesized through an ancient polyketide biosynthetic pathway consisting of a series of anther-specific enzymes that are widely present in all land plant lineages. Tetraketide α-pyrone reductase 1 (TKPR1) and TKPR2 are two reductases catalyzing the final reduction of the carbonyl group of the polyketide synthase-synthesized tetraketide intermediates to hydroxylated α-pyrone compounds, important precursors of sporopollenin. In contrast to the functional conservation of many sporopollenin biosynthesis associated genes confirmed in diverse plant species, TKPR2’s role has been addressed only in Arabidopsis, where it plays a minor role in sporopollenin biosynthesis. We identified in gerbera two non-anther-specific orthologues of AtTKPR2, Gerbera reductase 1 (GRED1) and GRED2. Their dramatically expanded expression pattern implies involvement in pathways outside of the sporopollenin pathway. In this study, we show that GRED1 and GRED2 are still involved in sporopollenin biosynthesis with a similar secondary role as AtTKPR2 in Arabidopsis. We further show that this secondary role does not relate to the promoter of the gene, AtTKPR2 cannot rescue pollen development in Arabidopsis even when controlled by the AtTKPR1 promoter. We also identified the gerbera orthologue of AtTKPR1, GTKPR1, and characterized its crucial role in gerbera pollen development. GTKPR1 is the predominant TKPR in gerbera pollen wall formation, in contrast to the minor roles GRED1 and GRED2. GTKPR1 is in fact an excellent target for engineering male-sterile gerbera cultivars in horticultural plant breeding.

scholarly journals Overexpression of Sesame Polyketide Synthase A Leads to Abnormal Pollen Development in Arabidopsis

2021 ◽  
Author(s):  
Tianyu Li ◽  
Ting Zhou ◽  
Yuanxiao Yang ◽  
Hongyan Liu ◽  
Fang Zhou ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Hybrid Breeding ◽  
Pollen Wall ◽  
Wall Structure ◽  
Ultrastructural Observation ◽  
Wild Type ◽  
In Planta ◽  
Male Sterile ◽  
Crop Species ◽  
Cytoplasmic Inclusions

Abstract Background: Sesame is a great reservoir of bioactive constituents and unique antioxidant components and is widely used for its nutritional and medicinal value. The expanding demands for sesame seeds are putting pressure on sesame breeders to develop reliable high-yielding varieties. Heterosis utilization is an efficient way to increase sesame yield. Polyketide synthases (PKSs) are critical enzymes in the biosynthesis of sporopollenin, a primary component of pollen exine. Their in planta functions are being investigated for application in crop breeding.Results: In this study, we cloned the sesame POLYKETIDE SYNTHASE A (SiPKSA) and examined its function in male sterility. SiPKSA was specifically expressed in sesame flower buds, and its expression was significantly higher in sterile sesame anthers than in fertile anthers at the tetrad and microspore development stage. Further overexpression of SiPKSA in Arabidopsis caused transgenic plants male sterile. Ultrastructural observation showed that the pollen grains of SiPKSA-overexpressing plants contained few cytoplasmic inclusions and exhibited an abnormal pollen wall structure, with a thicker exine layer compared with wild type. In agreement with it, the expression of a set of sporopollenin biosynthesis-related genes and the contents of fatty acids and phenolics were significantly altered in anthers of SiPKSA-overexpressing plants compared with wild type during anther development. Conclusion: These findings highlighted that overexpression of SiPKSA in Arabidopsis might cause excessive sporopollenin biosynthesis to influence pollen and pollen wall development, leading to male sterile, suggesting that its manipulation might improve hybrid breeding in sesame and other crop species.

scholarly journals OsMYB80 Regulates Anther Development and Pollen Fertility by Targeting Multiple Biological Pathways

2020 ◽  
Vol 61 (5) ◽  
pp. 988-1004 ◽  
Author(s):  
Xiaoying Pan ◽  
Wei Yan ◽  
Zhenyi Chang ◽  
Yingchao Xu ◽  
Ming Luo ◽  
...  
Keyword(s):  
Pollen Development ◽  
Male Fertility ◽  
Gene Networks ◽  
Affinity Purification ◽  
Anther Development ◽  
Rna Seq ◽  
Male Sterile ◽  
New Information ◽  
Gel Shift Assay

Abstract Pollen development is critical to the reproductive success of flowering plants, but how it is regulated is not well understood. Here, we isolated two allelic male-sterile mutants of OsMYB80 and investigated how OsMYB80 regulates male fertility in rice. OsMYB80 was barely expressed in tissues other than anthers, where it initiated the expression during meiosis, reached the peak at the tetrad-releasing stage and then quickly declined afterward. The osmyb80 mutants exhibited premature tapetum cell death, lack of Ubisch bodies, no exine and microspore degeneration. To understand how OsMYB80 regulates anther development, RNA-seq analysis was conducted to identify genes differentially regulated by OsMYB80 in rice anthers. In addition, DNA affinity purification sequencing (DAP-seq) analysis was performed to identify DNA fragments interacting with OsMYB80 in vitro. Overlap of the genes identified by RNA-seq and DAP-seq revealed 188 genes that were differentially regulated by OsMYB80 and also carried an OsMYB80-interacting DNA element in the promoter. Ten of these promoter elements were randomly selected for gel shift assay and yeast one-hybrid assay, and all showed OsMYB80 binding. The 10 promoters also showed OsMYB80-dependent induction when co-expressed in rice protoplast. Functional annotation of the 188 genes suggested that OsMYB80 regulates male fertility by directly targeting multiple biological processes. The identification of these genes significantly enriched the gene networks governing anther development and provided much new information for the understanding of pollen development and male fertility.

scholarly journals Increased expression of the MALE STERILITY1 transcription factor gene results in temperature-sensitive male sterility in barley

2020 ◽  
Vol 71 (20) ◽  
pp. 6328-6339
Author(s):  
José Fernández-Gómez ◽  
Behzad Talle ◽  
Zoe A Wilson
Keyword(s):  
Transcription Factor ◽  
Male Sterility ◽  
Pollen Development ◽  
Breeding Systems ◽  
Hybrid Breeding ◽  
Temperature Sensitive ◽  
Hybrid Vigour ◽  
Male Sterile ◽  
The Impact

Abstract Understanding the control of fertility is critical for crop yield and breeding; this is particularly important for hybrid breeding to capitalize upon the resultant hybrid vigour. Different hybrid breeding systems have been adopted; however, these are challenging and crop specific. Mutants with environmentally reversible fertility offer valuable opportunities for hybrid breeding. The barley HvMS1 gene encodes a PHD-finger transcription factor that is expressed in the anther tapetum, which is essential for pollen development and causes complete male sterility when overexpressed in barley. This male sterility is due at least in part to indehiscent anthers resulting from incomplete tapetum degeneration, failure of anther opening, and sticky pollen under normal growth conditions (15 °C). However, dehiscence and fertility are restored when plants are grown at temperatures >20 °C, or when transferred to >20 °C during flowering prior to pollen mitosis I, with transfer at later stages unable to rescue fertility in vivo. As far as we are aware, this is the first report of thermosensitive male sterility in barley. This offers opportunities to understand the impact of temperature on pollen development and potential applications for environmentally switchable hybrid breeding systems; it also provides a ‘female’ male-sterile breeding tool that does not need emasculation to facilitate backcrossing.

scholarly journals A Silent Exonic Mutation in a Rice Integrin-α FG-GAP Repeat-Containing Gene Causes Male-Sterility by Affecting mRNA Splicing

2020 ◽  
Vol 21 (6) ◽  
pp. 2018 ◽  
Author(s):  
Ting Zou ◽  
Dan Zhou ◽  
Wenjie Li ◽  
Guoqiang Yuan ◽  
Yang Tao ◽  
...  
Keyword(s):  
Pollen Development ◽  
Molecular Mapping ◽  
Higher Plants ◽  
Donor Site ◽  
Splice Junction ◽  
Splice Donor Site ◽  
Terrestrial Plants ◽  
Male Sterile ◽  
Intron Splice ◽  
Rice Mutant

Pollen development plays crucial roles in the life cycle of higher plants. Here we characterized a rice mutant with complete male-sterile phenotype, pollen-less 1 (pl1). pl1 exhibited smaller anthers with arrested pollen development, absent Ubisch bodies, necrosis-like tapetal hypertrophy, and smooth anther cuticular surface. Molecular mapping revealed a synonymous mutation in the fourth exon of PL1 co-segregated with the mutant phenotype. This mutation disrupts the exon-intron splice junction in PL1, generating aberrant mRNA species and truncated proteins. PL1 is highly expressed in the tapetal cells of developing anther, and its protein is co-localized with plasma membrane (PM) and endoplasmic reticulum (ER) signal. PL1 encodes an integrin-α FG-GAP repeat-containing protein, which has seven β-sheets and putative Ca2+-binding motifs and is broadly conserved in terrestrial plants. Our findings therefore provide insights into both the role of integrin-α FG-GAP repeat-containing protein in rice male fertility and the influence of exonic mutation on intronic splice donor site selection.

An ultrastructural study of pollen development in tomato (Lycopersicon esculentum). I. Tetrad to early binucleate microspore stage

1993 ◽  
Vol 71 (8) ◽  
pp. 1039-1047 ◽  
Author(s):  
P. L. Polowick ◽  
V. K. Sawhney
Keyword(s):  
Endoplasmic Reticulum ◽  
Lycopersicon Esculentum ◽  
Ultrastructural Study ◽  
Pollen Development ◽  
Pollen Wall ◽  
Ultrastructural Changes ◽  
Dense Matrix ◽  
Tetrad Stage ◽  
Microspore Stage ◽  
Electron Dense Matrix

Microspores undergo considerable ultrastructural changes between the tetrad and early binucleate microspore stages of microsporogenesis in tomato (Lycopersicon esculentum). Pollen wall deposition began late in the tetrad stage, and by the early microspore stage a lamellar foot layer and tectum were deposited. Sculpturing of the tectum was evident by the early binucleate microspore stage. Dictyosomes and vesicles were abundant during the period of pollen wall formation. Plastids were associated with the endoplasmic reticulum (ER) to form plastid–ER complexes, from the late tetrad to the vacuolate microspore stage. At the vacuolate microspore stage, endoplasmic reticulum independent of plastids was also observed, and at the early binucleate microspore stage ER was not associated with plastids. Free ribosomes were evenly distributed throughout the cytoplasm until the vacuolate microspore stage when they were organized into polysomes. Mitochondria were spherical to ellipsoid, with an electron-dense matrix and swollen cristae, until the early binucleate microspore stage when they were highly elongate and became convoluted. Key words: Lycopersicon esculentum, microsporogenesis, pollen development, tetrads, tomato, ultrastructure.

scholarly journals Tomato Male sterile 1035 is essential for pollen development and meiosis in anthers

2014 ◽  
Vol 65 (22) ◽  
pp. 6693-6709 ◽  
Author(s):  
Hee-Jin Jeong ◽  
Jin-Ho Kang ◽  
Meiai Zhao ◽  
Jin-Kyung Kwon ◽  
Hak-Soon Choi ◽  
...  
Keyword(s):  
Pollen Development ◽  
Male Sterile

Microspore and pollen development in six male-sterile mutants of Arabidopsis thaliana

1993 ◽  
Vol 71 (4) ◽  
pp. 629-638 ◽  
Author(s):  
J. Dawson ◽  
Z. A. Wilson ◽  
M. G. M. Aarts ◽  
A. F. Braithwaite ◽  
L. G. Briarty ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Key Words ◽  
Late Stage ◽  
Pollen Development ◽  
Ethyl Methanesulfonate ◽  
X Rays ◽  
Anther Dehiscence ◽  
Wild Type ◽  
Male Sterile ◽  
Stamen Filament

Five new recessive male-sterile mutants of Arabidopsis thaliana were isolated following seed mutagenesis by X-rays and ethyl methanesulfonate. The cytology of plants homozygous for the msY and msW mutations suggested that pollen development in these lines became abnormal at or before meiosis. The msK mutation caused faulty timing of synthesis or turnover and distribution of callose. In plants homozygous for the msZ mutation, pollen development failed at a late stage. In wild-type plants, the stamen filament elongated just prior to anther dehiscence. In contrast, in the msZ mutant stamen elongation did not occur. Pollen in msH homozygotes was fertile, but anthers failed to dehisce. The msI mutant of J.H. Van der Ween and P. Wirtz (1968. Euphytica 17: 371 – 377) was included in the present study. Pollen development in this mutant failed shortly after microspore release from tetrads. Complementation tests confirmed that the ms mutations were at different loci. Reduced transmission of certain ms genes was observed. Key words: Arabidopsis thaliana, male sterile mutants, anther dehiscence, callose, inheritance.

Sign in / Sign up

Export Citation Format

Share Document