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 this 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 quantitative real-time PCR. Genistein was detected in the transgenic lines using liquid chromatography with tandem mass spectrometry. Subsequently, the transgenic lines were evaluated against the rice blast pathogen, isolate YJ54 (race IB-54). The results indicated that >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 >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.

Post-harvest storage loss in sugar beets due to root rot and respiration can cause >20% sugar loss. Breeding strategies focused on factors contributing to improved post-harvest storage quality are of great importance to prevent losses. Using 16S rRNA and ITS sequencing and sugar beet mutational breeding lines with high disease resistance (R), along with a susceptible (S) commercial cultivar, the role of root microbiome and metabolome in storage performance was investigated. The R lines in general showed higher abundances of bacterial phyla, Patescibacteria at the M time point, and Cyanobacteria and Desulfobacterota at the L time point. Amongst fungal phyla, Basidiomycota (including Athelia) and Ascomycota were predominant in diseased samples. Linear discriminant analysis Effect Size (LEfSe) identified bacterial taxa such as Micrococcales, Micrococcaceae, Bacilli, Glutamicibacter, Nesterenkonia, and Paenarthrobacter as putative biomarkers associated with resistance in the R lines. Further functional enrichment analysis showed a higher abundance of bacteria, such as those related to the super pathway of pyrimidine deoxyribonucleoside degradation, L-tryptophan biosynthesis at M and L, and fungi, such as those associated with the biosynthesis of L-iditol 2-dehydrogenase at L in the R lines. Metabolome analysis of the roots revealed higher enrichment of pathways associated with arginine, proline, alanine, aspartate, and glutamate metabolism at M, in addition to beta-alanine and butanoate metabolism at L in the R lines. Correlation analysis between the microbiome and metabolites indicated that the root’s biochemical composition, such as the presence of nitrogen-containing secondary metabolites, may regulate relative abundances of key microbial candidates contributing to better post-harvest storage.