Mutants Disrupted in the Type III Secretion System of Bradyrhizobium elkanii BLY3-8 Overcame Nodulation Restriction by Rj3-genotype Soybean

Miku Shobudani; Aung Zaw Htwe; Takeo Yamakawa; Matsujiro Ishibashi; Hirohito Tsurumaru

doi:10.1264/jsme2.ME19151

Mutants Disrupted in the Type III Secretion System of Bradyrhizobium elkanii BLY3-8 Overcame Nodulation Restriction by Rj₃-genotype Soybean

Microbes Environ. 2020;35(2):ME19151. doi: 10.1264/jsme2.ME19151.

Authors

Miku Shobudani¹, Aung Zaw Htwe², Takeo Yamakawa³, Matsujiro Ishibashi⁴, Hirohito Tsurumaru⁴

Affiliations

¹ Graduate School of Agricultural Science, Kagoshima University.
² Department of Agronomy, Yezin Agricultural University.
³ Faculty of Agriculture, Kyushu University.
⁴ Faculty of Agriculture, Kagoshima University.

Abstract

Bradyrhizobium elkanii BLY3-8 does not form nodules on the roots of Rj₃-genotype soybean (cultivar D-51). This is a cultivar-specific nodulation restriction. The genes A6X20_40975 and A6X20_41030 in strain BLY3-8 were predicted to encode the transcriptional activator and apparatus of the type III secretion system (T3SS) (the proteins TtsI and RhcJ), respectively. Mutants disrupted in these genes overcame the nodulation restriction. These results suggest that an effector injected via T3SS into Rj₃-genotype soybean is involved in nodulation restriction by Rj₃-genotype soybean.

Keywords: Bradyrhizobium; Rj3; T3SS; nodulation; soybean.

MeSH terms

Bradyrhizobium / genetics*
Gene Expression Regulation, Bacterial
Genotype
Glycine max / genetics
Glycine max / microbiology*
Mutation
Plant Root Nodulation / genetics*
Symbiosis
Type III Secretion Systems / genetics*

Substances

Type III Secretion Systems

Supplementary concepts

Bradyrhizobium elkanii