Developmental northern-blot analysis of candidate stigma-specific gene expression. Total RNA was extracted from S. squalidus tissues; each lane contains 10 μg of total RNA. Lane 1, root; lane 2, leaf; lane 3, stem; lane 4, small capitulum bud (2–3 mm); lane 5, medium capitulum bud (5–6 mm); lane 6, large capitulum bud (8–9 mm); lane 7, open capitulum; lane 8, floret buds; lane 9, mix of open florets and buds; lane 10, florets all open; lane 11, mature stigmas; lane 12, pollen. The RNA was probed separately with cytochrome P450 (A; GO255238), calcium-binding kinase (B; GO255154), nodulin (C; GO255182), myoinositol oxygenase (D; GO255123), membrane-associated protein (E; GO255107), and nematode resistance protein (F; GO255085). G represents a loading control.