Hordeins are expressed in microspore-derived embryos and also during male gametophytic and very early stages of seed development.
Microspore-derived embryos induced by anther or isolated-microspore culture display certain characteristics of zygotic embryos. Furthermore, the expression of certain endosperm genes has been described in these non-zygotic embryos. The expression of hordein genes encoding the main barley endosperm proteins has been studied using a wide range of methods (RT-PCR, in situ hybridization, ELISA sandwich, western blotting immunocytochemistry, and cytochemistry) to ascertain their presence or absence during the induction and first stages of microspore embryogenesis. Due to the very sensitive techniques used it was possible to detect for the first time hordein expression during microspore embryogenesis. Surprisingly, these hordeins were also detected at different stages of male gametophytic development as well as during the very early stages of seed development, when they have not hitherto been detected. The expression and localization of these storage proteins and their corresponding transcripts provide new information about barley microspore embryogenesis and its relationship to zygotic embryogenesis. Although only small quantities of hordeins are accumulated during microspore embryogenesis they seem to be necessary for the initial development of the microspore-derived embryo. This idea is supported by the changes detected in their concentration throughout this process and is in accordance with previously published data concerning the importance of endosperm proteins for embryo development in both microspore culture and in planta.
Pulido
Amada
A
Department of Plant Biochemistry, Cell and Molecular Biology, EEZ, CSIC, Profesor Albareda 1, E-18008 Granada, Spain.
Hernando
Alberto
A
Bakos
Ferenc
F
Méndez
Enrique
E
Devic
Martine
M
Barnabás
Beata
B
Olmedilla
Adela
A
D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005983:Glutens; D001467:Hordeum / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D010940:Plant Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D011058:Pollen / Q000254:growth & development / Q000378:metabolism; D055315:Prolamins; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D046509:Tissue Culture Techniques
D010940:Plant Proteins; D055315:Prolamins; D012333:RNA, Messenger; D005983:Glutens