Acid Fuchsin Staining of ABAP1 Transgenic Lines Infected Roots

Acid fuchsin staining was performed in infected roots of ABAP1/abap1, ABAP1^OE, and wild-type seedlings as described by de Almeida-Engler et al. (2016), to track nematode development within the roots. The whole infected roots (40 DAI) were fixed and stained for 5 h in a solution of equal parts of 95% ethanol and glacial acetic acid, containing 17.5 mg/L acid fuchsin. The root tissue and galls were distained by incubating in a solution of chloral hydrate (0.2 g/ml in water) for 16 h. After rinsing the roots several times with tap water, roots containing nematodes were stored in acidified glycerol (five drops of 1.0 M HCl were added to 50 ml of glycerol). Nematode-infected roots were observed with a digital camera (Axiocam; Zeiss).