Intercellular communication in Arabidopsis thaliana pollen discovered via AHG3 transcript movement from the vegetative cell to sperm

An Arabidopsis pollen grain (male gametophyte) consists of three cells: the vegetative cell, which forms the pollen tube, and two sperm cells enclosed within the vegetative cell. It is still unclear if there is intercellular communication between the vegetative cell and the sperm cells. Here we show that ABA-hypersensitive germination3 (AHG3), encoding a protein phosphatase, is specifically transcribed in the vegetative cell but predominantly translated in sperm cells. We used a series of deletion constructs and promoter exchanges to document transport of AHG3 transcripts from the vegetative cell to sperm and showed that their transport requires sequences in both the 5′ UTR and the coding region. Thus, in addition its known role in transporting sperm during pollen tube growth, the vegetative cell also contributes transcripts to the sperm cells.

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Five Gametophytic Mutations Affecting Pollen Development and Pollen Tube Growth in Arabidopsis thaliana

Genetics ◽

10.1093/genetics/158.4.1773 ◽

2001 ◽

Vol 158 (4) ◽

pp. 1773-1783 ◽

Cited By ~ 1

Author(s):

Antonia Procissi ◽

Solveig de Laissardière ◽

Madina Férault ◽

Daniel Vezon ◽

Georges Pelletier ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Development ◽

Male Gametophyte ◽

Pollen Grains ◽

Segregation Ratio ◽

Variable Number ◽

Tube Growth ◽

Mutant Lines

Abstract Mutant analysis represents one of the most reliable approaches to identifying genes involved in plant development. The screening of the Versailles collection of Arabidopsis thaliana T-DNA insertion transformants has allowed us to isolate different mutations affecting male gametophytic functions and viability. Among several mutated lines, five have been extensively studied at the genetic, molecular, and cytological levels. For each mutant, several generations of selfing and outcrossing have been carried out, leading to the conclusion that all these mutations are tagged and affect only the male gametophyte. However, only one out of the five mutations is completely penetrant. A variable number of T-DNA copies has integrated in the mutant lines, although all segregate at one mutated locus. Two mutants could be defined as “early mutants”: the mutated genes are presumably expressed during pollen grain maturation and their alteration leads to the production of nonfunctional pollen grains. Two other mutants could be defined as “late mutant” since their pollen is able to germinate but pollen tube growth is highly disturbed. Screening for segregation ratio distortions followed by thorough genetic analysis proved to be a powerful tool for identifying gametophytic mutations of all phases of pollen development.

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The Long Journey of Pollen Tube in the Pistil

International Journal of Molecular Sciences ◽

10.3390/ijms19113529 ◽

2018 ◽

Vol 19 (11) ◽

pp. 3529 ◽

Cited By ~ 13

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.

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Two Expansin Genes, AtEXPA4 and AtEXPB5, Are Redundantly Required for Pollen Tube Growth and AtEXPA4 Is Involved in Primary Root Elongation in Arabidopsis thaliana

Genes ◽

10.3390/genes12020249 ◽

2021 ◽

Vol 12 (2) ◽

pp. 249

Author(s):

Weimiao Liu ◽

Liai Xu ◽

Hui Lin ◽

Jiashu Cao

Keyword(s):

Arabidopsis Thaliana ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Cell Walls ◽

Root Elongation ◽

Expression Patterns ◽

Primary Root ◽

Pollen Grains ◽

Tube Growth ◽

Cell Wall Binding

The growth of plant cells is inseparable from relaxation and expansion of cell walls. Expansins are a class of cell wall binding proteins, which play important roles in the relaxation of cell walls. Although there are many members in expansin gene family, the functions of most expansin genes in plant growth and development are still poorly understood. In this study, the functions of two expansin genes, AtEXPA4 and AtEXPB5 were characterized in Arabidopsis thaliana. AtEXPA4 and AtEXPB5 displayed consistent expression patterns in mature pollen grains and pollen tubes, but AtEXPA4 also showed a high expression level in primary roots. Two single mutants, atexpa4 and atexpb5, showed normal reproductive development, whereas atexpa4atexpb5 double mutant was defective in pollen tube growth. Moreover, AtEXPA4 overexpression enhanced primary root elongation, on the contrary, knocking out AtEXPA4 made the growth of primary root slower. Our results indicated that AtEXPA4 and AtEXPB5 were redundantly involved in pollen tube growth and AtEXPA4 was required for primary root elongation.

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Persistent directional growth capability in Arabidopsis thaliana pollen tubes after nuclear elimination from the apex

Nature Communications ◽

10.1038/s41467-021-22661-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Kazuki Motomura ◽

Hidenori Takeuchi ◽

Michitaka Notaguchi ◽

Haruna Tsuchi ◽

Atsushi Takeda ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Pollen Tube ◽

Sperm Cell ◽

Pollen Tubes ◽

Vegetative Nucleus ◽

Sperm Cells ◽

Apical Region ◽

Basal Region ◽

Specific Expression ◽

Directional Growth

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.

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Pollination in Arabidopsis thaliana: Cell-Cell Interaction During Pollen Tube Growth

Cell and Developmental Biology of Arabinogalactan-Proteins ◽

10.1007/978-1-4615-4207-0_32 ◽

2000 ◽

pp. 285-286

Author(s):

K. A. Lennon ◽

S. Roy ◽

P. K. Hepler ◽

E. M. Lord

Keyword(s):

Arabidopsis Thaliana ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Cell Interaction ◽

Tube Growth ◽

Cell Cell

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Transcriptome and translatome changes in germinated pollen under heat stress uncover roles of transporter genes involved in pollen tube growth

10.1101/2020.05.29.122937 ◽

2020 ◽

Cited By ~ 1

Author(s):

Laetitia Poidevin ◽

Javier Forment ◽

Dilek Unal ◽

Alejandro Ferrando

Keyword(s):

Arabidopsis Thaliana ◽

Heat Stress ◽

High Temperature ◽

Heat Shock ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Tube Growth ◽

Heat Shock Genes ◽

Germinated Pollen

ABSTRACTPlant reproduction is one key biological process very sensitive to heat stress and, as a consequence, enhanced global warming poses serious threats to food security worldwide. In this work we have used a high-resolution ribosome profiling technology to study how heat affects both the transcriptome and the translatome of Arabidopsis thaliana pollen germinated in vitro. Overall, a high correlation between transcriptional and translational responses to high temperature was found, but specific regulations at the translational level were also present. We show that bona fide heat shock genes are induced by high temperature indicating that in vitro germinated pollen is a suitable system to understand the molecular basis of heat responses. Concurrently heat induced significant down-regulation of key membrane transporters required for pollen tube growth, thus uncovering heat-sensitive targets. We also found that a large subset of the heat-repressed transporters is specifically up-regulated, in a coordinated manner, with canonical heat-shock genes in pollen tubes grown in vitro and semi in vivo, based on published transcriptomes from Arabidopsis thaliana. Ribosome footprints were also detected in gene sequences annotated as non-coding, highlighting the potential for novel translatable genes and translational dynamics.

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Pollen tube incompatibility reaction on the stigma in selfpollinated Sinapis alba L.

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1996.017 ◽

2014 ◽

Vol 65 (1-2) ◽

pp. 101-105 ◽

Cited By ~ 1

Author(s):

Renata Śnieżko ◽

Krystyna Winiarczyk

Keyword(s):

Pollen Tube ◽

Pollen Tube Growth ◽

Pollen Grains ◽

Pollen Tubes ◽

Sinapis Alba ◽

Pollen Grain ◽

Tube Growth ◽

Sinapis Alba L ◽

Growth Changes ◽

Incompatibility Reaction

After selfpollination of <em>Sinapis alba</em> L. pollen tubes growth is inhibited on the stigma. The pollen grains germinate 3-4 hours after pollination. The pollen give rise to one or more pollen tubes. They grow along the papillae. In the place of contact between the papilla and pollen tube the pellicula is digested. Then the direction of pollen tube growth changes completely. Pollen tubes grow back on the exine of their own pollen grain, or turn into the air. The pollen tubes growth was inhibited in 6-8 hours after selfpollination. After crosspollination usually there is no incompatibility reaction.

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Actin During Pollen Germination

Journal of Cell Science ◽

10.1242/jcs.86.1.1 ◽

1986 ◽

Vol 86 (1) ◽

pp. 1-8

Author(s):

J. HESLOP-HARRISON ◽

Y. HESLOP-HARRISON ◽

M. CRESTI ◽

A. TIEZZI ◽

F. CIAMPOLINI

Keyword(s):

Medium Release ◽

Pollen Tube ◽

Vegetative Cell ◽

Pollen Germination ◽

Pollen Grain ◽

Actin Microfilaments ◽

Vegetative Cells ◽

Stage Of Development ◽

Angiosperm Species

The cytoplasm of the vegetative cell of the ungerminated pollen grain of Endymton non-scriplus and other angiosperm species contains numerous fusiform bodies sometimes exceeding 15μm in length and 2.5 μm in width, which bind fluorescent-labelled phalloidin and are likely therefore to constitute a storage form of actin. The bodies are dispersed during the activation of the pollen, being replaced by aggregates of slender phalloidin-binding fibrils, which converge towards the germination apertures and are present in the emerging pollen tube. The storage bodies appear to be homologous with crystalline-fibrillar structures, shown in an earlier paper to be abundantly present in the vegetative cells of Nicotiana pollen. These are composed of massive aggregates of linearly disposed units with individual widths of 4–7 nm, probably to be interpreted as actin microfilaments. Vegetative-cell protoplasts from mature but ungerminated pollen disrupted in osmotically balancing medium release extended phalloidin-binding fibrils of a kind not observed in the intact grain. It is suggested that these are derived by the rapid dissociation of the compact actin storage bodies present in the vegetative cell at this stage of development.

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