Transgenic soybean overexpressing Gm SAMT 1 exhibits resistance to multiple‐ HG types of soybean cyst nematode Heterodera glycines

• Published in: Plant biotechnology journal Vol. 14; no. 11; pp. 2100 - 2109
• Main Authors: Lin, Jingyu, Mazarei, Mitra, Zhao, Nan, Hatcher, Catherine N., Wuddineh, Wegi A., Rudis, Mary, Tschaplinski, Timothy J., Pantalone, Vincent R., Arelli, Prakash R., Hewezi, Tarek, Chen, Feng, Stewart, Charles Neal
• Format: Journal Article
• Language: English
• Published: 01.11.2016
• ISSN: 1467-7644; 1467-7652
• DOI: 10.1111/pbi.12566

Summary Soybean ( Glycine max (L.) Merr.) salicylic acid methyl transferase (Gm SAMT 1) catalyses the conversion of salicylic acid to methyl salicylate. Prior results showed that when Gm SAMT 1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode ( SCN ), Heterodera glycines Ichinohe. In this study, we produced transgenic soybean overexpressing Gm SAMT 1 and characterized their response to various SCN races. Transgenic plants conferred a significant reduction in the development of SCN HG type 1.2.5.7 (race 2), HG type 0 (race 3) and HG type 2.5.7 (race 5). Among transgenic lines, Gm SAMT 1 expression in roots was positively associated with SCN resistance. In some transgenic lines, there was a significant decrease in salicylic acid titer relative to control plants. No significant seed yield differences were observed between transgenics and control soybean plants grown in one greenhouse with 22 °C day/night temperature, whereas transgenic soybean had higher yield than controls grown a warmer greenhouse (27 °C day/23 °C night) temperature. In a 1‐year field experiment in Knoxville, TN, there was no significant difference in seed yield between the transgenic and nontransgenic soybean under conditions with negligible SCN infection. We hypothesize that Gm SAMT 1 expression affects salicylic acid biosynthesis, which, in turn, attenuates SCN development, without negative consequences to soybean yield or other morphological traits. Thus, we conclude that Gm SAMT 1 overexpression confers broad resistance to multiple SCN races, which would be potentially applicable to commercial production.