The Pollen Tube Oscillator: Towards a Molecular Mechanism of Tip Growth?

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.

Download Full-text

Ca2+-Activated Reactive Oxygen Species Production by Arabidopsis RbohH and RbohJ Is Essential for Proper Pollen Tube Tip Growth

The Plant Cell ◽

10.1105/tpc.113.120642 ◽

2014 ◽

Vol 26 (3) ◽

pp. 1069-1080 ◽

Cited By ~ 130

Author(s):

Hidetaka Kaya ◽

Ryo Nakajima ◽

Megumi Iwano ◽

Masahiro M. Kanaoka ◽

Sachie Kimura ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Pollen Tube ◽

Reactive Oxygen Species Production ◽

Tip Growth ◽

Reactive Oxygen ◽

Oxygen Species ◽

Species Production

Download Full-text

Signaling in Pollen Tube Growth: Beyond the Tip of the Polarity Iceberg

Plants ◽

10.3390/plants8060156 ◽

2019 ◽

Vol 8 (6) ◽

pp. 156 ◽

Cited By ~ 4

Author(s):

Nolan Scheible ◽

Andrew McCubbin

Keyword(s):

Pollen Tube ◽

Signaling Pathways ◽

Pollen Tube Growth ◽

Tip Growth ◽

Holistic Approach ◽

Pollen Tubes ◽

Small Gtpase ◽

Tube Growth ◽

Concerted Action ◽

Current State

The coordinated growth of pollen tubes through floral tissues to deliver the sperm cells to the egg and facilitate fertilization is a highly regulated process critical to the Angiosperm life cycle. Studies suggest that the concerted action of a variety of signaling pathways underlies the rapid polarized tip growth exhibited by pollen tubes. Ca2+ and small GTPase-mediated pathways have emerged as major players in the regulation of pollen tube growth. Evidence suggests that these two signaling pathways not only integrate with one another but also with a variety of other important signaling events. As we continue to elucidate the mechanisms involved in pollen tube growth, there is a growing importance in taking a holistic approach to studying these pathways in order to truly understand how tip growth in pollen tubes is orchestrated and maintained. This review considers our current state of knowledge of Ca2+-mediated and GTPase signaling pathways in pollen tubes, how they may intersect with one another, and other signaling pathways involved. There will be a particular focus on recent reports that have extended our understanding in these areas.

Download Full-text

A Gain-of-Function Mutation of Arabidopsis Lipid Transfer Protein 5 Disturbs Pollen Tube Tip Growth and Fertilization

The Plant Cell ◽

10.1105/tpc.109.070854 ◽

2009 ◽

Vol 21 (12) ◽

pp. 3902-3914 ◽

Cited By ~ 70

Author(s):

Keun Chae ◽

Chris A. Kieslich ◽

Dimitrios Morikis ◽

Seung-Chul Kim ◽

Elizabeth M. Lord

Keyword(s):

Pollen Tube ◽

Tip Growth ◽

Lipid Transfer Protein ◽

Lipid Transfer ◽

Gain Of Function ◽

Transfer Protein

Download Full-text

F-Actin Organization and Pollen Tube Tip Growth in Arabidopsis Are Dependent on the Gametophyte-Specific Armadillo Repeat Protein ARO1

The Plant Cell ◽

10.1105/tpc.108.061028 ◽

2008 ◽

Vol 20 (10) ◽

pp. 2798-2814 ◽

Cited By ~ 27

Author(s):

Marina Gebert ◽

Thomas Dresselhaus ◽

Stefanie Sprunck

Keyword(s):

Pollen Tube ◽

Tip Growth ◽

Repeat Protein ◽

Actin Organization ◽

Armadillo Repeat

Download Full-text

Pollination Sub-Systems Distinguished by Pollen Tube Arrest after Incompatible Interspecific Crosses in Rhododendron (Ericaceae)

Journal of Cell Science ◽

10.1242/jcs.53.1.255 ◽

1982 ◽

Vol 53 (1) ◽

pp. 255-277

Author(s):

ELIZABETH G. WILLIAMS ◽

BRUCE R. KNOX ◽

JOHN L. ROUSE

Keyword(s):

Pollen Tube ◽

Tip Growth ◽

Interspecific Cross ◽

Embryo Sac ◽

Epifluorescence Microscopy ◽

Interspecific Crosses ◽

Abnormal Behaviour ◽

Callose Deposition ◽

Variable Diameter ◽

Stigmatic Exudate

The cytology of compatible and interspecific incompatible pollinations has been followed in selected species of the genus Rhododendron (Ericaceae). Pollinated pistils were fixed, cleared, stained in decolourized aniline blue, and observed by epifluorescence microscopy. Ten different abnormalities of arrested pollen tube tips have been detected, including burst, tapered, swollen, coiled, spiralling, spiky and variable diameter syndromes. A series of five errors of callose deposition in incompatible tubes has also been defined. Six different regions in the pistil for expression of pollen tube arrest have been found, including the stigmatic exudate, the mucilage of the upper and lower style canal, the ovary loculus, the micropyle. There may also be abnormal behaviour after entry into the embryo sac. Both the site of pollen tube arrest within the pistil, and the error syndrome of tip growth and callose deposition anomalies, are characteristic of each interspecific cross. These results are discussed in relation to the genetic control of reproduction.

Download Full-text