Isolation and characterization of a full-length resistance gene homolog from soybean.
Using mixed resistance gene analogs as probes, a putative resistance gene (KR1) was isolated from soybean and characterized further. The KR1 protein consists of a Toll/interleukin receptor (TIR) domain, a nucleotide binding site (NBS) domain, an imperfect leucine-rich repeat (LRR) domain and two C-terminal transmembrane segments. Due to these features, KR1 represents a distinct member in the TIR-NBS-LRR class of resistance genes. Southern-blot analysis indicated that there were several KR1-related sequences within the soybean genome, and two polymorphic loci were mapped onto linkage group L. KR1 was induced by SA treatment and soybean mosaic virus (SMV) infection in the resistant line (Kefeng 1). An orthologue (NR1) and a homologue (NR2) of the KR1 gene were also identified in the SMV susceptible-line Nannong1138-2. Sequencing analysis revealed that NR2 was highly homologous to KR1 and NR1, but had a 21-bp deletion. Moreover, the NR1, NR2 transcription and the ratio of NR1/ NR2 was up-regulated by viral infection in Nannong1138-2. These results indicated the complexity of the regulatory mechanism in the plant responses to SMV infection.
He
Chao-Ying
CY
Plant Biotechnology Laboratory, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Tian
Ai-Guo
AG
Zhang
Jin-Song
JS
Zhang
Zhi-Yong
ZY
Gai
Jun-Yi
JY
Chen
Shou-Yi
SY
D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000494:pharmacology; D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D008040:Genetic Linkage; D006790:Host-Parasite Interactions / Q000187:drug effects / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D010942:Plant Viruses / Q000187:drug effects / Q000502:physiology*; D020156:Salicylic Acid / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000187:drug effects / Q000235:genetics* / Q000821:virology
D000890:Anti-Infective Agents; D020156:Salicylic Acid