scholarly journals Ultrastructure of fertilization in Plumbago zeylanica

2014 ◽  
Vol 50 (1-2) ◽  
pp. 185-189 ◽  
Author(s):  
Scott D. Russell ◽  
David D. Cass
Keyword(s):  
Cell Wall ◽  
Pollen Tube ◽  
Female Gametophyte ◽  
Tube Growth ◽  
Vegetative Nucleus ◽  
Plumbago Zeylanica ◽  
Specialized Cell ◽  
Wall Ingrowths ◽  
Male Gametes ◽  
Cell Wall Ingrowths

The synergidless female gametophyte of <em>Plumbago zeylanica</em> receives the pollen tube through specialized cell wall ingrowths at the base of the egg; tube growth continues between egg and central cells. Pollen tube discharge occurs between egg and central cell and results in release of two male gametes, vegetative nucleus, and some pollen cytoplasm. Except for the location of gamete discharge, details of transmission and fusion of gametic nuclei appear to conform to reports of these processes in taxa possessing conventional embryo sacs.

Fertilization in Plumbago zeylanica: entry and discharge of the pollen tube in the embryo sac

1982 ◽  
Vol 60 (11) ◽  
pp. 2219-2230 ◽  
Author(s):  
Scott D. Russell
Keyword(s):  
Cell Wall ◽  
Pollen Tube ◽  
Female Gametophyte ◽  
Embryo Sac ◽  
Central Cell ◽  
Vegetative Nucleus ◽  
Egg Cell ◽  
Ultrastructural Organization ◽  
Plumbago Zeylanica ◽  
Male Gametes

The ultrastructural organization of the megagametophyte of Plumbago zeylanica, which lacks synergids, was examined in chemically and physically fixed ovules after entry of the pollen tube. Similar to angiosperms with conventionally organized megagametophytes, the pollen tube enters the ovule through a micropyle, formed by the inner integument, and approaches the female gametophyte by growing between nucellar cells. Unlike other described female gametophytes, however, continued pollen tube growth results in direct penetration of the base of the egg through cell wall projections forming a filiform apparatus and is completed between the egg and central cell without disrupting either of these cells' plasma membranes. A terminal pollen tube aperture forms when the pollen tube reaches an area of strong curvature near the summit of the egg; this results in the release of two sperm cells, the vegetative nucleus, and a limited amount of pollen cytoplasm. The formerly continuous chalazal egg cell wall is locally disrupted near the tip of the pollen tube and apparently is thus modified for reception of male gametes. Discharged pollen cytoplasm rapidly degenerates between the egg and central cell, but unlike pollen tube discharge in conventionally organized megagametophytes, it is unassociated with the degeneraton of any receptor cell within the female gametophyte. Sperm nuclei are transmitted, one to the egg and the other to the central cell, to effect double fertilization by nuclear fusion with their respective female reproductive nuclei. The vegetative nucleus and discharged pollen cytoplasm degenerate between the developing embryo and endosperm during early embryogenesis. The emerging concept that the egg of Plumbago possesses combined egg and synergid functions is supported by the present study and suggests that the megagametophyte of this plant displays a highly specialized egg apparatus composed exclusively of a single, modified egg cell.

scholarly journals A Complex Journey: Cell Wall Remodeling, Interactions, and Integrity During Pollen Tube Growth

2020 ◽  
Vol 11 ◽  
Author(s):  
Milagros Cascallares ◽  
Nicolás Setzes ◽  
Fernanda Marchetti ◽  
Gabriel Alejandro López ◽  
Ayelén Mariana Distéfano ◽  
...  
Keyword(s):  
Cell Wall ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Molecular Mechanisms ◽  
Tube Growth ◽  
Polar Growth ◽  
Cell Wall Synthesis ◽  
Male Gametes ◽  
Pollen Cell ◽  
Extended Path

In flowering plants, pollen tubes undergo a journey that starts in the stigma and ends in the ovule with the delivery of the sperm cells to achieve double fertilization. The pollen cell wall plays an essential role to accomplish all the steps required for the successful delivery of the male gametes. This extended path involves female tissue recognition, rapid hydration and germination, polar growth, and a tight regulation of cell wall synthesis and modification, as its properties change not only along the pollen tube but also in response to guidance cues inside the pistil. In this review, we focus on the most recent advances in elucidating the molecular mechanisms involved in the regulation of cell wall synthesis and modification during pollen germination, pollen tube growth, and rupture.

scholarly journals Exocyst mutants suppress pollen tube growth and cell wall structural defects of hydroxyproline O‐arabinosyltransferase mutants

2020 ◽  
Vol 103 (4) ◽  
pp. 1399-1419
Author(s):  
Steven Beuder ◽  
Alexandria Dorchak ◽  
Ashwini Bhide ◽  
Svenning Rune Moeller ◽  
Bent L. Petersen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Structural Defects

scholarly journals To preserve or to destroy, that is the question: the role of the cell wall integrity pathway in pollen tube growth

2019 ◽  
Vol 52 ◽  
pp. 131-139 ◽  
Author(s):  
Hannes Vogler ◽  
Gorka Santos-Fernandez ◽  
Martin A Mecchia ◽  
Ueli Grossniklaus
Keyword(s):  
Cell Wall ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Cell Wall Integrity ◽  
Tube Growth ◽  
Cell Wall Integrity Pathway

scholarly journals Inhibition of Apoplastic Calmodulin Impairs Calcium Homeostasis and Cell Wall Modeling during Cedrus deodara Pollen Tube Growth

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e55411 ◽  
Author(s):  
Li Wang ◽  
Xueqin Lv ◽  
Hong Li ◽  
Min Zhang ◽  
Hong Wang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Pollen Tube ◽  
Calcium Homeostasis ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Cedrus Deodara

The root–fungus interface as an indicator of symbiont interaction in ectomycorrhizae

1987 ◽  
Vol 17 (8) ◽  
pp. 846-854 ◽  
Author(s):  
H. B. Massicotte ◽  
C. A. Ackerley ◽  
R. L. Peterson
Keyword(s):  
Cell Wall ◽  
Epidermal Cell ◽  
Apical Meristem ◽  
Epidermal Cells ◽  
Wall Ingrowths ◽  
Wall Ingrowth ◽  
Hartig Net ◽  
Epidermal Cell Wall ◽  
Different Strains ◽  
Cell Wall Ingrowths

Seedlings of Alnuscrispa (Ait.) Pursh, Alnusrubra Bong., Eucalyptuspilularis Sm., and Betulaalleghaniensis Britt. were grown in plastic pouches and subsequently inoculated with Alpovadiplophloeus (Zeller & Dodge) Trappe & Smith (two different strains), Pisolithustinctorius (Pers.) Coker & Couch, and Laccariabicolor (R. Mre) Orton, respectively, to form ectomycorrhizae insitu. Alnus seedlings were inoculated with Frankia prior to inoculation with the mycosymbiont. The interface established between A. crispa and A. diplophloeus was complex, involving wall ingrowth formation in root epidermal cells and infoldings in Hartig net hyphae. Alnusrubra – A. diplophloeus ectomycorrhizae had an interface lacking epidermal cell wall ingrowths but with infoldings in Hartig net hyphae. The interface between E. pilularis –. tinctorius consisted of branching Hartig net hyphae between radially enlarged epidermal cells lacking wall ingrowths. Ectomycorrhizae between B. alleghaniensis and L. bicolor developed unique interfaces with radially enlarged epidermal cells near the apical meristem, which synthesized dense vacuolar deposits. Very fine branchings occurred in Hartig net hyphae.

scholarly journals Associations between the acclimation of phloem-cell wall ingrowths in minor veins and maximal photosynthesis rate

2014 ◽  
Vol 5 ◽  
Author(s):  
William W. Adams III ◽  
Christopher M. Cohu ◽  
Véronique Amiard ◽  
Barbara Demmig-Adams
Keyword(s):  
Cell Wall ◽  
Photosynthesis Rate ◽  
Wall Ingrowths ◽  
Phloem Cell ◽  
Cell Wall Ingrowths
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