Transgenic Rice Expressing Isoflavone Synthase Gene from Soybean Shows Resistance Against Blast Fungus (Magnaporthe oryzae)

Abstract

The isoflavones are a group of plant secondary metabolites primarily synthesized in legumes and are known for their role in improving human health and plant disease resistance. The isoflavones, especially genistein, act as precursors for the production of phytoalexins, which may induce broad-spectrum disease resistance in plants. In the present study, we screened transgenic rice lines expressing the isoflavone synthase (GmIFS1) gene from soybean for rice blast (Magnaporthe oryzae) resistance. Two homozygous transgenic lines (I2 and I10), based on single copy gene integration, were identified. The expression of GmIFS1 in transgenic lines was confirmed by qRT-PCR. Genistein was detected in the transgenic lines using LC-MS/MS. Subsequently, the transgenic lines were evaluated against the rice blast pathogen, isolate YJ54 (race IB-54). The results indicated that more than 60% of the plants in both the lines (I2 and I10) showed resistance against the blast pathogen. The progenies of one of the resistant transgenic lines (I10) also showed more than 65% resistance against rice blast. The resistance of these transgenic lines against rice blast may be attributed to the synthesis of isoflavone (genistein) in rice.

Exogenous genistein enhances soybean resistance to Xanthomonas axonopodis pv. glycines

“…61 The increase in genistein concentration led to an increase in the concentration of downstream isoflavones, such as genistin and Biochanin A. Transgenic rice, expressing isoflavone synthase gene from soybean, showed resistance to Magnaporthe oryzae, and this effect was attributed to the synthesis of genistein in rice. 62 Cheng et al reported that isoflavone synthase expression was correlated with the increase in disease resistance to soybean mosaic virus. 63 Silencing of genes for daidzein biosynthesis increased the concentrations of genistein and its derivatives but reduced the resistance to P. sojae.…”

“…Transgenic soybean plants with enhanced isoflavone biosynthesis showed a 4.36‐fold increase in genistein concentration and enhanced resistance to mosaic virus 61 . The increase in genistein concentration led to an increase in the concentration of downstream isoflavones, such as genistin and Biochanin A. Transgenic rice, expressing isoflavone synthase gene from soybean, showed resistance to Magnaporthe oryzae , and this effect was attributed to the synthesis of genistein in rice 62 . Cheng et al .…”

Joint transcriptomic and metabolomic analysis reveals the mechanism of low-temperature tolerance in Hosta ventricosa

“…For example, it has been shown to increase the resistance of alfalfa ( Medicago sativa ) to Acyrthosiphon pisum [ 47 ], and of rice ( O . sativa ) to Magnaporthe oryzae [ 48 ]. Genistein can also improve the response of plants to adverse environmental conditions.…”

Recent Progress in Rice Broad-Spectrum Disease Resistance

“…In addition to genes from Arabidopsis , transgenic rice plants expressing resistant Lr34 allele from wheat showed increased resistance against multiple isolates of the hemibiotrophic pathogen M. oryzae by delaying invasive hyphal growth [ 133 ]. In another example, transgenic rice lines expressing the isoflavone synthase (GmIFS1) gene from soybean contributed to the synthesis of isoflavone (genistein) to promote M. oryzae resistance, indicating that the synthesis of heterologous secondary metabolites, such as isoflavone, is a good way to develop blast resistance in rice [ 134 ]. As such, we believe that engineering resistant rice through ectopic transcription of defense genes cloud be a broadly applicable new strategy, which may lead to reduced use of pesticides and lightening the selection pressure of resistance pathogens.…”