scholarly journals Cytoskeleton, Transglutaminase and Gametophytic Self-Incompatibility in the Malinae (Rosaceae)

2019 ◽  
Vol 20 (1) ◽  
pp. 209 ◽  
Author(s):  
Stefano Del Duca ◽  
Iris Aloisi ◽  
Luigi Parrotta ◽  
Giampiero Cai
Keyword(s):  
Pollen Tube ◽  
Current Knowledge ◽  
Male Gametophyte ◽  
Self Incompatibility ◽  
Protein Targets ◽  
Complex Process ◽  
Self Fertilization ◽  
Tgase Activity ◽  
Rosaceae Family ◽  
Substrate Proteins

Self-incompatibility (SI) is a complex process, one out of several mechanisms that prevent plants from self-fertilizing to maintain and increase the genetic variability. This process leads to the rejection of the male gametophyte and requires the co-participation of numerous molecules. Plants have evolved two distinct SI systems, the sporophytic (SSI) and the gametophytic (GSI) systems. The two SI systems are markedly characterized by different genes and proteins and each single system can also be divided into distinct subgroups; whatever the mechanism, the purpose is the same, i.e., to prevent self-fertilization. In Malinae, a subtribe in the Rosaceae family, i.e., Pyrus communis and Malus domestica, the GSI requires the production of female determinants, known as S-RNases, which penetrate the pollen tube to interact with the male determinants. Beyond this, the penetration of S-RNase into the pollen tube triggers a series of responses involving membrane proteins, such as phospholipases, intracellular variations of cytoplasmic Ca2+, production of reactive oxygen species (ROS) and altered enzymatic activities, such as that of transglutaminase (TGase). TGases are widespread enzymes that catalyze the post-translational conjugation of polyamines (PAs) to different protein targets and/or the cross-linking of substrate proteins leading to the formation of cross-linked products with high molecular mass. When actin and tubulin are the substrates, this destabilizes the cytoskeleton and inhibits the pollen-tube’s growth process. In this review, we will summarize the current knowledge of the relationship between S-RNase penetration, TGase activity and cytoskeleton function during GSI in the Malinae.

scholarly journals Self-incompatibility and Self-fruitfulness in Pear cv. Agua de Aranjuez

2007 ◽  
Vol 132 (2) ◽  
pp. 166-171 ◽  
Author(s):  
Javier Sanzol ◽  
Maria Herrero
Keyword(s):  
Pollen Tube ◽  
Fruit Set ◽  
Parthenocarpic Fruit ◽  
Self Incompatibility ◽  
Variable Response ◽  
Self Pollination ◽  
Fruit Setting ◽  
Self Fertilization ◽  
Growing Conditions ◽  
Performance Results

Most pear (Pyrus communis L.) cultivars are impaired to set fruit under self-pollination, because self-fertilization is prevented by a gametophytic self-incompatibility system. However, accumulated information in this species shows that often for a same cultivar, after self-pollination, a variable response in fruit set can be obtained in different years or growing conditions. In this work, we characterize self-incompatibility and self-fruitfulness in ‘Agua de Aranjuez’, the main Spanish pear cultivar, which also shows a variable response to self-pollination. Two years with a different fruit setting response after self-pollination, one with no fruit set and the other with a moderate fruit set, were compared for parthenocarpic fruit development and for pollen tube performance. Results show that in both years, this cultivar behaves as self-incompatible with absence of parthenocarpy. In selfed flowers, most pollen tubes are arrested in the upper half of the style, although in a small proportion of the styles, a pollen tube can reach the base of the style and eventually effect fertilization. Self-fertilization, although occurring at a low level, can explain the fruit set levels obtained under self-pollination given that flowers with just one fertilized ovule are able to set fruit. This behavior could explain confusing results about self-fruitfulness in ‘Agua de Aranjuez’ and other pear cultivars.

scholarly journals The Long Journey of Pollen Tube in the Pistil

2018 ◽  
Vol 19 (11) ◽  
pp. 3529 ◽  
Author(s):  
Yang-Yang Zheng ◽  
Xian-Ju Lin ◽  
Hui-Min Liang ◽  
Fang-Fei Wang ◽  
Li-Yu Chen
Keyword(s):  
Pollen Tube ◽  
Female Gametophyte ◽  
Male Gametophyte ◽  
Pollen Grain ◽  
Tubular Structure ◽  
Future Research ◽  
Sperm Cells ◽  
Double Fertilization ◽  
Complex Process ◽  
Pass Through

In non-cleistogamous plants, the male gametophyte, the pollen grain is immotile and exploits various agents, such as pollinators, wind, and even water, to arrive to a receptive stigma. The complex process of pollination involves a tubular structure, i.e., the pollen tube, which delivers the two sperm cells to the female gametophyte to enable double fertilization. The pollen tube has to penetrate the stigma, grow in the style tissues, pass through the septum, grow along the funiculus, and navigate to the micropyle of the ovule. It is a long journey for the pollen tube and its two sperm cells before they meet the female gametophyte, and it requires very accurate regulation to perform successful fertilization. In this review, we update the knowledge of molecular dialogues of pollen-pistil interaction, especially the progress of pollen tube activation and guidance, and give perspectives for future research.

scholarly journals 753 PB 143 POLLEN-PISTIL INCOMPATIBILITY DIFFERENCES BETWEEN MANZANILLO AND FRANTOIO OLIVE (Olea europaea L.) CULTIVARS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 541a-541 ◽  
Author(s):  
J. Cuevas ◽  
L. Rallo ◽  
H.F. Rapoport
Keyword(s):  
Pollen Tube ◽  
Reproductive Behavior ◽  
Pollen Tube Growth ◽  
Fruit Set ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Olive Cultivars ◽  
Self Fertilization ◽  
Incompatibility Reaction ◽  
Reproductive Processes

We have compared reproductive processes and fruit set in Manzanillo and Frantoio olive cultivars which are reported in the literature respectively as incompatible and partially compatible. The same incompatibility reaction was observed in both cultivars. Pollen tube growth was almost completely inhibited beyond the stigma, but some degree of self-fertilization was accomplished. However, in both cultivars cross-pollination provided a earlier and higher level of fertilization. Differences in self-incompatibility behavior seemed related to the level and the amount of delay in self-fertilization. In the compatible variety, Frantoio, self-pollen tube growth was accomplished more rapidly and showed a higher level of self-fertilization than in the incompatible Manzanillo cultivar. Fruit set matched reproductive behavior.

Sequence and Structural Diversity of the S Locus Genes From Different Lines With the Same Self-Recognition Specificities in Brassica oleracea

Genetics ◽  
2000 ◽  
Vol 154 (1) ◽  
pp. 413-420 ◽  
Author(s):  
Makoto Kusaba ◽  
Masanori Matsushita ◽  
Keiichi Okazaki ◽  
Yoko Satta ◽  
Takeshi Nishio
Keyword(s):  
Structural Diversity ◽  
Receptor Protein ◽  
Self Incompatibility ◽  
S Locus ◽  
High Similarity ◽  
Putative Receptor ◽  
Recognition Specificity ◽  
Polymorphic Genes ◽  
Self Recognition ◽  
Self Fertilization

Abstract Self-incompatibility (SI) is a mechanism for preventing self-fertilization in flowering plants. In Brassica, it is controlled by a single multi-allelic locus, S, and it is believed that two highly polymorphic genes in the S locus, SLG and SRK, play central roles in self-recognition in stigmas. SRK is a putative receptor protein kinase, whose extracellular domain exhibits high similarity to SLG. We analyzed two pairs of lines showing cross-incompatibility (S2 and S2-b; S13 and S13-b). In S2 and S2-b, SRKs were more highly conserved than SLGs. This was also the case with S13 and S13-b. This suggests that the SRKs of different lines must be conserved for the lines to have the same self-recognition specificity. In particular, SLG2-b showed only 88.5% identity to SLG2, which is comparable to that between the SLGs of different S haplotypes, while SRK2-b showed 97.3% identity to SRK2 in the S domain. These findings suggest that the SLGs in these S haplotypes are not important for self-recognition in SI.

scholarly journals Protein Analysis of Pollen Tubes after the Treatments of Membrane Trafficking Inhibitors Gains Insights on Molecular Mechanism Underlying Pollen Tube Polar Growth

2021 ◽  
Vol 40 (2) ◽  
pp. 205-222
Author(s):  
Monica Scali ◽  
Alessandra Moscatelli ◽  
Luca Bini ◽  
Elisabetta Onelli ◽  
Rita Vignani ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Actin Cytoskeleton ◽  
Membrane Trafficking ◽  
Tip Growth ◽  
Male Gametophyte ◽  
Pollen Tubes ◽  
Structural Features ◽  
Two Dimensional Gel Electrophoresis ◽  
Depth Analysis

AbstractPollen tube elongation is characterized by a highly-polarized tip growth process dependent on an efficient vesicular transport system and largely mobilized by actin cytoskeleton. Pollen tubes are an ideal model system to study exocytosis, endocytosis, membrane recycling, and signaling network coordinating cellular processes, structural organization and vesicular trafficking activities required for tip growth. Proteomic analysis was applied to identifyNicotiana tabacumDifferentially Abundant Proteins (DAPs) after in vitro pollen tube treatment with membrane trafficking inhibitors Brefeldin A, Ikarugamycin and Wortmannin. Among roughly 360 proteins separated in two-dimensional gel electrophoresis, a total of 40 spots visibly changing between treated and control samples were identified by MALDI-TOF MS and LC–ESI–MS/MS analysis. The identified proteins were classified according to biological processes, and most proteins were related to pollen tube energy metabolism, including ammino acid synthesis and lipid metabolism, structural features of pollen tube growth as well modification and actin cytoskeleton organization, stress response, and protein degradation. In-depth analysis of proteins corresponding to energy-related pathways revealed the male gametophyte to be a reliable model of energy reservoir and dynamics.

scholarly journals Testing of self-(in)compatibility in apricot cultivars from European breeding programmes

2013 ◽  
Vol 40 (No. 2) ◽  
pp. 65-71 ◽  
Author(s):  
D. Milatović ◽  
D. Nikolić ◽  
B. Krška
Keyword(s):  
Fluorescence Microscopy ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Reliable Method ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Self Incompatibility ◽  
Breeding Programmes

Self-(in)compatibility was tested in 40 new apricot cultivars from European breeding programmes. Pollen-tube growth in pistils from laboratory pollinations was analysed using the fluorescence microscopy. Cultivars were considered self-compatible if at least one pollen tube reached the ovary in the majority of pistils. Cultivars were considered self- incompatible if the growth of pollen tubes in the style stopped along with formation of characteristic swellings. Of the examined cultivars, 18 were self-compatible and 22 were self-incompatible. Fluorescence microscopy provides a relatively rapid and reliable method to determine self-incompatibility in apricot cultivars.      

scholarly journals Paving the Way for Fertilization: The Role of the Transmitting Tract

2021 ◽  
Vol 22 (5) ◽  
pp. 2603
Author(s):  
Ana Marta Pereira ◽  
Diana Moreira ◽  
Sílvia Coimbra ◽  
Simona Masiero
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Current Knowledge ◽  
Embryo Sac ◽  
Tube Growth ◽  
Signaling Cascades ◽  
Secretory Cells ◽  
Transmitting Tract ◽  
Specialized Tissue

Angiosperm reproduction relies on the precise growth of the pollen tube through different pistil tissues carrying two sperm cells into the ovules’ embryo sac, where they fuse with the egg and the central cell to accomplish double fertilization and ultimately initiate seed development. A network of intrinsic and tightly regulated communication and signaling cascades, which mediate continuous interactions between the pollen tube and the sporophytic and gametophytic female tissues, ensures the fast and meticulous growth of pollen tubes along the pistil, until it reaches the ovule embryo sac. Most of the pollen tube growth occurs in a specialized tissue—the transmitting tract—connecting the stigma, the style, and the ovary. This tissue is composed of highly secretory cells responsible for producing an extensive extracellular matrix. This multifaceted matrix is proposed to support and provide nutrition and adhesion for pollen tube growth and guidance. Insights pertaining to the mechanisms that underlie these processes remain sparse due to the difficulty of accessing and manipulating the female sporophytic tissues enclosed in the pistil. Here, we summarize the current knowledge on this key step of reproduction in flowering plants with special emphasis on the female transmitting tract tissue.

scholarly journals The Contribution of Endothelial-Mesenchymal Transition to Atherosclerosis

2021 ◽  
Vol 1 (1) ◽  
pp. 39-54
Author(s):  
Jinyu Zhang ◽  
Stella C. Ogbu ◽  
Phillip R. Musich ◽  
Douglas P. Thewke ◽  
Zhiqiang Yao ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Vascular Inflammation ◽  
Mesenchymal Phenotype ◽  
Mesenchymal Transition ◽  
Common Chronic Disease ◽  
Complex Process ◽  
Endothelial To Mesenchymal Transition ◽  
Key Pathways ◽  
Endothelial Mesenchymal Transition ◽  
Progression Of Atherosclerosis

Atherosclerosis is a chronic progressive condition in which the wall of the artery develops abnormalities and causes thickening of the blood vessels. The development of atherosclerosis is a complex process characterized by vascular inflammation and the growth of atherosclerotic plaques that eventually lead to compromised blood flow. The endothelial to mesenchymal transition (EndMT) is a phenomenon whereby endothelial cells lose their endothelial properties and acquire a mesenchymal phenotype similar to myofibroblast and smooth muscle cells. This process is considered a key contributor to the development and, importantly, the progression of atherosclerosis. Thus, therapeutically targeting the EndMT will provide a broad strategy to attenuate the development of atherosclerosis. Here, we review our current knowledge of EndMT in atherosclerosis including several key pathways such as hypoxia, TGF-β signaling, inflammation, and environmental factors during the development of atherosclerosis. In addition, we discuss several transgenic mouse models for studying atherosclerosis. Taken together, rapidly accelerating knowledge and continued studies promise further progress in preventing this common chronic disease.

The development of the male gametophyte and spermatogenesis in Taxus baccata L

1986 ◽  
Vol 228 (1250) ◽  
pp. 85-96 ◽  
Keyword(s):  
Pollen Tube ◽  
De Novo ◽  
Male Gametophyte ◽  
Generative Cell ◽  
Equal Size ◽  
Taxus Baccata ◽  
Transverse Wall ◽  
Proximal Pole ◽  
Spermatogenous Cell ◽  
Tube Cell

The development of the male gametophyte of Taxus baccata has been studied over a period of 20 weeks, from germination of the microspore in February to spermatogenesis in July. A few days after germination the microspore nucleus divides and a transverse wall forms at the equator cutting off the small generative cell and a large tube cell. The latter immediately begins to expand to form the pollen tube. The first division thus establishes the polarity of the gametophyte and the generative cell is regarded as proximal. The transverse wall is ephemeral, and within six weeks it has disappeared. The nucleus of the generative cell divides while still at the proximal pole. The two daughter nuclei are unequal in size, but they remain associated and together move distally. The larger nucleus eventually becomes the nucleus of the spermatogenous cell, and the smaller the sterile nucleus. The spermatogenous cell acquires a distinctive cytoplasm and becomes surrounded by a wall which arises de novo . The nucleus of the spermatogenous cell enlarges, but always remains towards one side of the cell so that at mitosis the spindle is contained within one hemisphere. After division the wall of the spermatogenous cell is ruptured and the two sperms are released as naked nuclei of equal size. The cytoplasm of the spermatogenous cell degenerates as it enters the tube, but remains recognizable until fertilization.

scholarly journals Hanks-Type Serine/Threonine Protein Kinases and Phosphatases in Bacteria: Roles in Signaling and Adaptation to Various Environments

2018 ◽  
Vol 19 (10) ◽  
pp. 2872 ◽  
Author(s):  
Monika Janczarek ◽  
José-María Vinardell ◽  
Paulina Lipa ◽  
Magdalena Karaś
Keyword(s):  
Dna Binding ◽  
Essential Role ◽  
Current Knowledge ◽  
Response Regulator ◽  
Protein Targets ◽  
Regulatory Pathways ◽  
Translational Machinery ◽  
Signaling Systems ◽  
Cellular Processes ◽  
Division Cell

Reversible phosphorylation is a key mechanism that regulates many cellular processes in prokaryotes and eukaryotes. In prokaryotes, signal transduction includes two-component signaling systems, which involve a membrane sensor histidine kinase and a cognate DNA-binding response regulator. Several recent studies indicate that alternative regulatory pathways controlled by Hanks-type serine/threonine kinases (STKs) and serine/threonine phosphatases (STPs) also play an essential role in regulation of many different processes in bacteria, such as growth and cell division, cell wall biosynthesis, sporulation, biofilm formation, stress response, metabolic and developmental processes, as well as interactions (either pathogenic or symbiotic) with higher host organisms. Since these enzymes are not DNA-binding proteins, they exert the regulatory role via post-translational modifications of their protein targets. In this review, we summarize the current knowledge of STKs and STPs, and discuss how these enzymes mediate gene expression in prokaryotes. Many studies indicate that regulatory systems based on Hanks-type STKs and STPs play an essential role in the regulation of various cellular processes, by reversibly phosphorylating many protein targets, among them several regulatory proteins of other signaling cascades. These data show high complexity of bacterial regulatory network, in which the crosstalk between STK/STP signaling enzymes, components of TCSs, and the translational machinery occurs. In this regulation, the STK/STP systems have been proved to play important roles.

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