**3.8 Flavonoids in soybean breeding**

In adverse conditions, soybean (*Glycine max*) productivity drops significantly. Soybean breeding might benefit from discovering regulatory components that impart stress tolerance. *HSFB2b*, a class B heat shock factor, enhances salt tolerance by activating one subset of flavonoid biosynthesis-related genes and blocking the repressor *GmNAC2* to release another collection of flavonoid biosynthesis-related genes. Silencing *GmFNSII*, the principal flavone-producing gene, reduces flavone levels and increases salt sensitivity in hairy soybean roots [108]. Leaf-chewing insects are severe pests of soybeans, lowering seed quality and limiting output (*G. max*). The CRISPR/ Cas9 expression vector was introduced into the soybean cultivar via agrobacteriummediated transformation, resulting in *Glyma.07 g110300-*gene mutants. A 33-bp deletion and a single-bp insertion in the *GmUGT* coding domain increased resistance to Cotton bollworm (*Helicoverpa armigera*) and Tobacco cutworm (*Spodoptera litura*). Furthermore, *GmUGT* overexpression made soybean species susceptible to *H. armigera* and *S. litura* [109].
