2.3. RNA isolation
Total RNA was isolated from boll of uninfected and A. flavusinfected
cotton using Spectrum total RNA isolation kit (Sigmae
Aldrich, St. Louis, MO) at different time points after infection. The
RNA was independently extracted from cottonseed and pericarp
from each infected locules (L1) and three adjacent/distal locules
(Adj), respectively. Total RNA was quantified by an ND-1000 spectrophotometer
(Nanodrop Technologies, Wilmington, DE). The RNA
integritywas also assessed by running 2 ml of total RNA in a 1.2% (w/
v) agarose/formaldehyde gel, stained with ethidium bromide, and
visualized under UV light. An aliquot of 1 mg RNA extracted from
adjacent/distal locules (Adj) of cottonseed or pericarp was pooled
for cDNA preparation.