Figure 1.

(A) SOD specific activity assay of EC proteins isolated from DOA-40 DPA seeds. Extracellular proteins were extracted from trichome-bearing cotton seeds using 1 M NaCl and assayed for SOD activity according to the method of Flohè and Ötting.¹⁷ PCW, primary cell wall stage; SCW, secondary cell wall stage. (B) Immunoblot analysis of GhCSD extracted from cotton seeds from 4–40 DPA using a plant CSD antibody. EC protein was separated on a 15% SDS-polyacrylamide gel and blotted to nitrocellulose. Primary antibody was anti-plant CSD (1:6000 dilution) (EnVirtue Biotechnologies Inc., Winchester, VA). Secondary antibody was horseradish peroxidase-conjugated donkey anti-rabbit IgG (1:2000 dilution) with detection by SuperSignal West Pico Chemiluminescent Substrate (Pierce, Rockford, IL). (C) Relative transcript abundance of GhCSD genes in fiber. Relative transcript abundance of GhCSD genes in 8-24 DPA fibers measured by Q-RT-PCR. Specific primers for GhCSD3 (5′-CCATGCTGGAGATT TGGGTA-3′/ 5′-TCAGCAAC CCATCAGGGC-3′) and cotton 18S rRNA (5′-CGTCCCTGCCCTTTGTACA-3′/5′-AACCTTCACCGGACCATTCA-3′) as a normalizer were designed using Primer Express software (version 2.0, Applied Biosystems, Foster City, CA). The specificity of primer annealing was examined by monitoring product dissociation. The fold difference is relative to the lowest transcript level present in 12 DPA fibers for GhCSD3.