Figure 1.

(a) Upland cotton plant and its different parts including a leaf epidermal gland (depicted as a black spot in the leaf) that produces terpenoid aldehyde (TA). (b) TA biosynthetic pathway in the genus Gossypium. TAs are derived from the common precursor, deoxyhemigossypol (dHG; C15). The dHG is converted into hemigossypol (HG), then two HG are joined to form gossypol (C30). Hemigossypolone (HGQ) is an oxidized form of dHG that is a precursor to form the heliocides (H1‐H4) (Figure 1b) (Opitz et al., 2008). The number of carbons and precursors are labeled in parenthesis at each step for this catalytic process