Open AccessOverexpression of a soybean salicylic acid methyltransferase gene confers resistance to soybean cyst nematode
Author(s) -
Lin Jingyu,
Mazarei Mitra,
Zhao Nan,
Zhu Junwei J.,
Zhuang Xiaofeng,
Liu Wusheng,
Pantalone Vincent R.,
Arelli Prakash R.,
Stewart Charles N.,
Chen Feng
Publication year - 2013
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12108
Subject(s) - salicylic acid , biology , soybean cyst nematode , complementary dna , systemic acquired resistance , gene , gene expression , heterodera , transgene , mutant , microbiology and biotechnology , biochemistry , arabidopsis , nematode , ecology
Summary Salicylic acid plays a critical role in activating plant defence responses after pathogen attack. Salicylic acid methyltransferase (SAMT) modulates the level of salicylic acid by converting salicylic acid to methyl salicylate. Here, we report that a SAMT gene from soybean ( GmSAMT1 ) plays a role in soybean defence against soybean cyst nematode ( Heterodera glycines Ichinohe, SCN). GmSAMT1 was identified as a candidate SCN defence‐related gene in our previous analysis of soybean defence against SCN using GeneChip microarray experiments. The current study started with the isolation of the full‐length cDNA s of GmSAMT1 from a SCN‐resistant soybean line and from a SCN‐susceptible soybean line. The two cDNA s encode proteins of identical sequences. The GmSAMT1 cDNA was expressed in Escherichia coli . Using in vitro enzyme assays, E. coli ‐expressed GmSAMT1 was confirmed to function as salicylic acid methyltransferase. The apparent Km value of GmSAMT1 for salicylic acid was approximately 46 μ m . To determine the role of GmSAMT1 in soybean defence against SCN, transgenic hairy roots overexpressing GmSAMT1 were produced and tested for SCN resistance. Overexpression of GmSAMT1 in SCN‐susceptible backgrounds significantly reduced the development of SCN, indicating that overexpression of GmSAMT1 in the transgenic hairy root system could confer resistance to SCN. Overexpression of GmSAMT1 in transgenic hairy roots was also found to affect the expression of selected genes involved in salicylic acid biosynthesis and salicylic acid signal transduction.