Cargando…
Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley
BACKGROUND: The ability to increase cellulose content and improve the stem strength of cereals could have beneficial applications in stem lodging and producing crops with higher cellulose content for biofuel feedstocks. Here, such potential is explored in the commercially important crop barley throu...
Autores principales: | , , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2015
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349714/ https://www.ncbi.nlm.nih.gov/pubmed/25850007 http://dx.doi.org/10.1186/s12870-015-0448-y |
_version_ | 1782360069789188096 |
---|---|
author | Tan, Hwei-Ting Shirley, Neil J Singh, Rohan R Henderson, Marilyn Dhugga, Kanwarpal S Mayo, Gwenda M Fincher, Geoffrey B Burton, Rachel A |
author_facet | Tan, Hwei-Ting Shirley, Neil J Singh, Rohan R Henderson, Marilyn Dhugga, Kanwarpal S Mayo, Gwenda M Fincher, Geoffrey B Burton, Rachel A |
author_sort | Tan, Hwei-Ting |
collection | PubMed |
description | BACKGROUND: The ability to increase cellulose content and improve the stem strength of cereals could have beneficial applications in stem lodging and producing crops with higher cellulose content for biofuel feedstocks. Here, such potential is explored in the commercially important crop barley through the manipulation of cellulose synthase genes (CesA). RESULTS: Barley plants transformed with primary cell wall (PCW) and secondary cell wall (SCW) barley cellulose synthase (HvCesA) cDNAs driven by the CaMV 35S promoter, were analysed for growth and morphology, transcript levels, cellulose content, stem strength, tissue morphology and crystalline cellulose distribution. Transcript levels of the PCW HvCesA transgenes were much lower than expected and silencing of both the endogenous CesA genes and introduced transgenes was often observed. These plants showed no aberrant phenotypes. Although attempts to over-express the SCW HvCesA genes also resulted in silencing of the transgenes and endogenous SCW HvCesA genes, aberrant phenotypes were sometimes observed. These included brittle nodes and, with the 35S:HvCesA4 construct, a more severe dwarfing phenotype, where xylem cells were irregular in shape and partially collapsed. Reductions in cellulose content were also observed in the dwarf plants and transmission electron microscopy showed a significant decrease in cell wall thickness. However, there were no increases in overall crystalline cellulose content or stem strength in the CesA over-expression transgenic plants, despite the use of a powerful constitutive promoter. CONCLUSIONS: The results indicate that the cellulose biosynthetic pathway is tightly regulated, that individual CesA proteins may play different roles in the synthase complex, and that the sensitivity to CesA gene manipulation observed here suggests that in planta engineering of cellulose levels is likely to require more sophisticated strategies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12870-015-0448-y) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-4349714 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-43497142015-03-05 Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley Tan, Hwei-Ting Shirley, Neil J Singh, Rohan R Henderson, Marilyn Dhugga, Kanwarpal S Mayo, Gwenda M Fincher, Geoffrey B Burton, Rachel A BMC Plant Biol Research Article BACKGROUND: The ability to increase cellulose content and improve the stem strength of cereals could have beneficial applications in stem lodging and producing crops with higher cellulose content for biofuel feedstocks. Here, such potential is explored in the commercially important crop barley through the manipulation of cellulose synthase genes (CesA). RESULTS: Barley plants transformed with primary cell wall (PCW) and secondary cell wall (SCW) barley cellulose synthase (HvCesA) cDNAs driven by the CaMV 35S promoter, were analysed for growth and morphology, transcript levels, cellulose content, stem strength, tissue morphology and crystalline cellulose distribution. Transcript levels of the PCW HvCesA transgenes were much lower than expected and silencing of both the endogenous CesA genes and introduced transgenes was often observed. These plants showed no aberrant phenotypes. Although attempts to over-express the SCW HvCesA genes also resulted in silencing of the transgenes and endogenous SCW HvCesA genes, aberrant phenotypes were sometimes observed. These included brittle nodes and, with the 35S:HvCesA4 construct, a more severe dwarfing phenotype, where xylem cells were irregular in shape and partially collapsed. Reductions in cellulose content were also observed in the dwarf plants and transmission electron microscopy showed a significant decrease in cell wall thickness. However, there were no increases in overall crystalline cellulose content or stem strength in the CesA over-expression transgenic plants, despite the use of a powerful constitutive promoter. CONCLUSIONS: The results indicate that the cellulose biosynthetic pathway is tightly regulated, that individual CesA proteins may play different roles in the synthase complex, and that the sensitivity to CesA gene manipulation observed here suggests that in planta engineering of cellulose levels is likely to require more sophisticated strategies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12870-015-0448-y) contains supplementary material, which is available to authorized users. BioMed Central 2015-02-21 /pmc/articles/PMC4349714/ /pubmed/25850007 http://dx.doi.org/10.1186/s12870-015-0448-y Text en © Tan et al.; licensee BioMed Central. 2015 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Article Tan, Hwei-Ting Shirley, Neil J Singh, Rohan R Henderson, Marilyn Dhugga, Kanwarpal S Mayo, Gwenda M Fincher, Geoffrey B Burton, Rachel A Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley |
title | Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley |
title_full | Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley |
title_fullStr | Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley |
title_full_unstemmed | Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley |
title_short | Powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley |
title_sort | powerful regulatory systems and post-transcriptional gene silencing resist increases in cellulose content in cell walls of barley |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349714/ https://www.ncbi.nlm.nih.gov/pubmed/25850007 http://dx.doi.org/10.1186/s12870-015-0448-y |
work_keys_str_mv | AT tanhweiting powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley AT shirleyneilj powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley AT singhrohanr powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley AT hendersonmarilyn powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley AT dhuggakanwarpals powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley AT mayogwendam powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley AT finchergeoffreyb powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley AT burtonrachela powerfulregulatorysystemsandposttranscriptionalgenesilencingresistincreasesincellulosecontentincellwallsofbarley |