The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform

Lacey A Samuels - One of the best experts on this subject based on the ideXlab platform.

  • new views of tapetum ultrastructure and pollen exine development in arabidopsis thaliana
    Annals of Botany, 2014
    Co-Authors: Teagen D Quilichini, Carl J Douglas, Lacey A Samuels
    Abstract:

    BACKGROUND AND AIMS: The Arabidopsis thaliana pollen cell wall is a complex structure consisting of an outer sporopollenin framework and lipid-rich coat, as well as an inner cellulosic wall. Although mutant analysis has been a useful tool to study pollen cell walls, the ultrastructure of the arabidopsis anther has proved to be challenging to preserve for electron microscopy. METHODS: In this work, high-pressure freezing/freeze substitution and transmission electron microscopy were used to examine the sequence of developmental events in the anther that lead to sporopollenin deposition to form the exine and the dramatic differentiation and death of the tapetum, which produces the pollen coat. KEY RESULTS: Cryo-fixation revealed a new view of the interplay between sporophytic anther tissues and gametophytic microspores over the course of pollen development, especially with respect to the intact microspore/pollen wall and the continuous tapetum epithelium. These data reveal the ultrastructure of tapetosomes and Elaioplasts, highly specialized tapetum organelles that accumulate pollen coat components. The tapetum and middle layer of the anther also remain intact into the tricellular pollen and late uninucleate microspore stages, respectively. CONCLUSIONS: This high-quality structural information, interpreted in the context of recent functional studies, provides the groundwork for future mutant studies where tapetum and microspore ultrastructure is assessed.

  • part of a special issue on plant cellwalls new views of tapetum ultrastructure and pollen exine development in arabidopsis thaliana
    2014
    Co-Authors: Teagen D Quilichini, Carl J Douglas, Lacey A Samuels
    Abstract:

    † Background and AimsTheArabidopsisthalianapollencellwallisacomplexstructureconsistingofanoutersporopollenin framework and lipid-rich coat, as well as an inner cellulosic wall. Although mutant analysis has been a usefultoolto study pollencell walls,theultrastructureof thearabidopsisanther hasproved tobe challenging topreserve for electron microscopy. † MethodsInthiswork,high-pressurefreezing/freezesubstitutionandtransmissionelectronmicroscopywereused toexaminethesequenceofdevelopmentaleventsintheantherthatleadtosporopollenindepositiontoformtheexine and the dramatic differentiation and death of the tapetum, which produces the pollen coat. † Key Results Cryo-fixation revealed a new view of the interplay between sporophytic anther tissues and gametophytic microspores over the course of pollen development, especially with respect to the intact microspore/pollen wall and the continuous tapetum epithelium. These data reveal the ultrastructure of tapetosomes and Elaioplasts, highly specialized tapetum organelles that accumulate pollen coat components. The tapetum and middle layer of the anther also remain intact into the tricellular pollen and late uninucleate microspore stages, respectively. † Conclusions This high-quality structural information, interpreted in the context of recent functional studies, provides the groundwork for future mutant studies where tapetum and microspore ultrastructure is assessed.

Verónica Albrecht-borth - One of the best experts on this subject based on the ideXlab platform.

  • Insights into chloroplast biogenesis and development.
    Biochimica et Biophysica Acta, 2015
    Co-Authors: Barry J. Pogson, Diep Ganguly, Verónica Albrecht-borth
    Abstract:

    In recent years many advances have been made to obtain insight into chloroplast biogenesis and development. In plants several plastids types exist such as the proplastid (which is the progenitor of all plastids), leucoplasts (group of colourless plastids important for storage including Elaioplasts (lipids), amyloplasts (starch) or proteinoplasts (proteins)), chromoplasts (yellow to orange-coloured due to carotenoids, in flowers or in old leaves as gerontoplasts), and the green chloroplasts. Chloroplasts are indispensable for plant development; not only by performing photosynthesis and thus rendering the plant photoautotrophic, but also for biochemical processes (which in some instances can also take place in other plastids types), such as the synthesis of pigments, lipids, and plant hormones and sensing environmental stimuli. Although we understand many aspects of these processes there are gaps in our understanding of the establishment of functional chloroplasts and their regulation. Why is that so? Even though chloroplast function is comparable in all plants and most of the algae, ferns and moss, detailed analyses have revealed many differences, specifically with respect to its biogenesis. As an update to our prior review on the genetic analysis of chloroplast biogenesis and development [1] herein we will focus on recent advances in Angiosperms (monocotyledonous and dicotyledonous plants) that provide novel insights and highlight the challenges and prospects for unravelling the regulation of chloroplast biogenesis specifically during the establishment of the young plants. This article is part of a Special Issue entitled: Chloroplast Biogenesis.

Teagen D Quilichini - One of the best experts on this subject based on the ideXlab platform.

  • new views of tapetum ultrastructure and pollen exine development in arabidopsis thaliana
    Annals of Botany, 2014
    Co-Authors: Teagen D Quilichini, Carl J Douglas, Lacey A Samuels
    Abstract:

    BACKGROUND AND AIMS: The Arabidopsis thaliana pollen cell wall is a complex structure consisting of an outer sporopollenin framework and lipid-rich coat, as well as an inner cellulosic wall. Although mutant analysis has been a useful tool to study pollen cell walls, the ultrastructure of the arabidopsis anther has proved to be challenging to preserve for electron microscopy. METHODS: In this work, high-pressure freezing/freeze substitution and transmission electron microscopy were used to examine the sequence of developmental events in the anther that lead to sporopollenin deposition to form the exine and the dramatic differentiation and death of the tapetum, which produces the pollen coat. KEY RESULTS: Cryo-fixation revealed a new view of the interplay between sporophytic anther tissues and gametophytic microspores over the course of pollen development, especially with respect to the intact microspore/pollen wall and the continuous tapetum epithelium. These data reveal the ultrastructure of tapetosomes and Elaioplasts, highly specialized tapetum organelles that accumulate pollen coat components. The tapetum and middle layer of the anther also remain intact into the tricellular pollen and late uninucleate microspore stages, respectively. CONCLUSIONS: This high-quality structural information, interpreted in the context of recent functional studies, provides the groundwork for future mutant studies where tapetum and microspore ultrastructure is assessed.

  • part of a special issue on plant cellwalls new views of tapetum ultrastructure and pollen exine development in arabidopsis thaliana
    2014
    Co-Authors: Teagen D Quilichini, Carl J Douglas, Lacey A Samuels
    Abstract:

    † Background and AimsTheArabidopsisthalianapollencellwallisacomplexstructureconsistingofanoutersporopollenin framework and lipid-rich coat, as well as an inner cellulosic wall. Although mutant analysis has been a usefultoolto study pollencell walls,theultrastructureof thearabidopsisanther hasproved tobe challenging topreserve for electron microscopy. † MethodsInthiswork,high-pressurefreezing/freezesubstitutionandtransmissionelectronmicroscopywereused toexaminethesequenceofdevelopmentaleventsintheantherthatleadtosporopollenindepositiontoformtheexine and the dramatic differentiation and death of the tapetum, which produces the pollen coat. † Key Results Cryo-fixation revealed a new view of the interplay between sporophytic anther tissues and gametophytic microspores over the course of pollen development, especially with respect to the intact microspore/pollen wall and the continuous tapetum epithelium. These data reveal the ultrastructure of tapetosomes and Elaioplasts, highly specialized tapetum organelles that accumulate pollen coat components. The tapetum and middle layer of the anther also remain intact into the tricellular pollen and late uninucleate microspore stages, respectively. † Conclusions This high-quality structural information, interpreted in the context of recent functional studies, provides the groundwork for future mutant studies where tapetum and microspore ultrastructure is assessed.

Barry J. Pogson - One of the best experts on this subject based on the ideXlab platform.

  • Insights into chloroplast biogenesis and development.
    Biochimica et Biophysica Acta, 2015
    Co-Authors: Barry J. Pogson, Diep Ganguly, Verónica Albrecht-borth
    Abstract:

    In recent years many advances have been made to obtain insight into chloroplast biogenesis and development. In plants several plastids types exist such as the proplastid (which is the progenitor of all plastids), leucoplasts (group of colourless plastids important for storage including Elaioplasts (lipids), amyloplasts (starch) or proteinoplasts (proteins)), chromoplasts (yellow to orange-coloured due to carotenoids, in flowers or in old leaves as gerontoplasts), and the green chloroplasts. Chloroplasts are indispensable for plant development; not only by performing photosynthesis and thus rendering the plant photoautotrophic, but also for biochemical processes (which in some instances can also take place in other plastids types), such as the synthesis of pigments, lipids, and plant hormones and sensing environmental stimuli. Although we understand many aspects of these processes there are gaps in our understanding of the establishment of functional chloroplasts and their regulation. Why is that so? Even though chloroplast function is comparable in all plants and most of the algae, ferns and moss, detailed analyses have revealed many differences, specifically with respect to its biogenesis. As an update to our prior review on the genetic analysis of chloroplast biogenesis and development [1] herein we will focus on recent advances in Angiosperms (monocotyledonous and dicotyledonous plants) that provide novel insights and highlight the challenges and prospects for unravelling the regulation of chloroplast biogenesis specifically during the establishment of the young plants. This article is part of a Special Issue entitled: Chloroplast Biogenesis.

Carl J Douglas - One of the best experts on this subject based on the ideXlab platform.

  • new views of tapetum ultrastructure and pollen exine development in arabidopsis thaliana
    Annals of Botany, 2014
    Co-Authors: Teagen D Quilichini, Carl J Douglas, Lacey A Samuels
    Abstract:

    BACKGROUND AND AIMS: The Arabidopsis thaliana pollen cell wall is a complex structure consisting of an outer sporopollenin framework and lipid-rich coat, as well as an inner cellulosic wall. Although mutant analysis has been a useful tool to study pollen cell walls, the ultrastructure of the arabidopsis anther has proved to be challenging to preserve for electron microscopy. METHODS: In this work, high-pressure freezing/freeze substitution and transmission electron microscopy were used to examine the sequence of developmental events in the anther that lead to sporopollenin deposition to form the exine and the dramatic differentiation and death of the tapetum, which produces the pollen coat. KEY RESULTS: Cryo-fixation revealed a new view of the interplay between sporophytic anther tissues and gametophytic microspores over the course of pollen development, especially with respect to the intact microspore/pollen wall and the continuous tapetum epithelium. These data reveal the ultrastructure of tapetosomes and Elaioplasts, highly specialized tapetum organelles that accumulate pollen coat components. The tapetum and middle layer of the anther also remain intact into the tricellular pollen and late uninucleate microspore stages, respectively. CONCLUSIONS: This high-quality structural information, interpreted in the context of recent functional studies, provides the groundwork for future mutant studies where tapetum and microspore ultrastructure is assessed.

  • part of a special issue on plant cellwalls new views of tapetum ultrastructure and pollen exine development in arabidopsis thaliana
    2014
    Co-Authors: Teagen D Quilichini, Carl J Douglas, Lacey A Samuels
    Abstract:

    † Background and AimsTheArabidopsisthalianapollencellwallisacomplexstructureconsistingofanoutersporopollenin framework and lipid-rich coat, as well as an inner cellulosic wall. Although mutant analysis has been a usefultoolto study pollencell walls,theultrastructureof thearabidopsisanther hasproved tobe challenging topreserve for electron microscopy. † MethodsInthiswork,high-pressurefreezing/freezesubstitutionandtransmissionelectronmicroscopywereused toexaminethesequenceofdevelopmentaleventsintheantherthatleadtosporopollenindepositiontoformtheexine and the dramatic differentiation and death of the tapetum, which produces the pollen coat. † Key Results Cryo-fixation revealed a new view of the interplay between sporophytic anther tissues and gametophytic microspores over the course of pollen development, especially with respect to the intact microspore/pollen wall and the continuous tapetum epithelium. These data reveal the ultrastructure of tapetosomes and Elaioplasts, highly specialized tapetum organelles that accumulate pollen coat components. The tapetum and middle layer of the anther also remain intact into the tricellular pollen and late uninucleate microspore stages, respectively. † Conclusions This high-quality structural information, interpreted in the context of recent functional studies, provides the groundwork for future mutant studies where tapetum and microspore ultrastructure is assessed.