Ethylene insensitivity conferred by a mutated Arabidopsis ethylene receptor gene alters nodulation in transgenic Lotus japonicus

Lohar, Dasharath, Stiller, Jiri, Kam, Jason, Stacey, Gary and Gresshoff, PM (2009) Ethylene insensitivity conferred by a mutated Arabidopsis ethylene receptor gene alters nodulation in transgenic Lotus japonicus. Annals of Botany, 104 2: 277-285. doi:10.1093/aob/mcp132


Author Lohar, Dasharath
Stiller, Jiri
Kam, Jason
Stacey, Gary
Gresshoff, PM
Title Ethylene insensitivity conferred by a mutated Arabidopsis ethylene receptor gene alters nodulation in transgenic Lotus japonicus
Formatted title
Ethylene insensitivity conferred by a mutated Arabidopsis ethylene receptor gene alters nodulation in transgenic Lotus japonicus
Journal name Annals of Botany   Check publisher's open access policy
ISSN 1095-8290
0305-7364
Publication date 2009-08
Sub-type Article (original research)
DOI 10.1093/aob/mcp132
Volume 104
Issue 2
Start page 277
End page 285
Total pages 9
Editor J. S. (Pat) Heslop-Harrison
Place of publication United Kingdom
Publisher Oxford University Press
Collection year 2010
Language eng
Subject C1
820503 Grain Legumes
820405 Soybeans
970106 Expanding Knowledge in the Biological Sciences
060702 Plant Cell and Molecular Biology
060110 Receptors and Membrane Biology
060703 Plant Developmental and Reproductive Biology
Abstract † Background and Aims Transgenics are used to demonstrate a causal relationship between ethylene insensitivity of a seedling legume plant, the level of ethylene receptor gene expression, lateral root growth and Mesorhizobium loti-induced nodule initiation. † Methods Lotus japonicus plants expressing the dominant etr1-1 allele of the Arabidopsis thaliana gene encoding a well-characterized mutated ethylene receptor were created by stable Agrobacterium tumefaciens transformation. Single insertion, homozygous lines were characterized for symbiotic properties. † Key Results Transgenic plants were ethylene insensitive as judged by the lack of the ‘Triple Response’, and their continued ability to grow and nodulate in the presence of inhibitory concentrations of ACC (1-aminocyclopropane- 1-carboxylic acid; an ethylene precursor). Transgenic plants with high insensitivity to ACC had significantly fewer lateral roots and exhibited increased nodulation while showing no altered nitrate sensitivity or lack of systemic autoregulation. Whereas ACC-insensitive shoot growth and nodulation were observed in transformants, root growth was inhibited similarly to the wild type. Increased nodulation was caused by increased infection and a seven-fold increase in nodules developing between xylem poles. Bacteroid numbers per symbiosome increased about 1.7-fold in ethylene-insensitive plants. †Conclusions The study further demonstrates multiple roles for ethylene in nodule initiation by influencing root cell infections and radial positioning, independent of autoregulation and nitrate inhibition of nodulation.
Formatted abstract
Background and Aims Transgenics are used to demonstrate a causal relationship between ethylene insensitivity of a seedling legume plant, the level of ethylene receptor gene expression, lateral root growth and Mesorhizobium loti-induced nodule initiation.
Methods Lotus japonicus plants expressing the dominant etr1-1 allele of the Arabidopsis thaliana gene encoding a well-characterized mutated ethylene receptor were created by stable Agrobacterium tumefaciens transformation. Single insertion, homozygous lines were characterized for symbiotic properties.
Key Results Transgenic plants were ethylene insensitive as judged by the lack of the ‘Triple Response’, and their continued ability to grow and nodulate in the presence of inhibitory concentrations of ACC (1-aminocyclopropane- 1-carboxylic acid; an ethylene precursor). Transgenic plants with high insensitivity to ACC had significantly
fewer lateral roots and exhibited increased nodulation while showing no altered nitrate sensitivity or lack of systemic autoregulation. Whereas ACC-insensitive shoot growth and nodulation were observed in transformants, root growth was inhibited similarly to the wild type. Increased nodulation was caused by increased infection and
a seven-fold increase in nodules developing between xylem poles. Bacteroid numbers per symbiosome increased about 1.7-fold in ethylene-insensitive plants.
Conclusions The study further demonstrates multiple roles for ethylene in nodule initiation by influencing root cell infections and radial positioning, independent of autoregulation and nitrate inhibition of nodulation.
Keyword Ethylene insensitivity
Lotus japonicus
Symbiosis
Phytohormone
Nodulation
Signal transduction
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Article (original research)
Collections: Centre for Integrative Legume Research Publications
2010 Higher Education Research Data Collection
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 33 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 37 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Thu, 03 Sep 2009, 07:48:42 EST by Mr Andrew Martlew on behalf of Centre for Integrative Legume Research