Changes in Levels of mRNAs for Cell Wall-Related Enzymes in Growing Cotton Fiber Cells

mRNAs for cell wall-related enzymes in developing cotton fiber cells were measured by reverse transcription-PCR analysis. Both endo-1,4-beta-glucanase and expansin mRNA levels were high during cell elongation but decreased when cell elongation ceased, and xyloglucan decreased. The endo-1,3-beta-glucanase mRNA level was very low in the elongating cells but increased gradually at the onset of secondary wall synthesis, accompanying the massive deposition of cellulose. Endoxyloglucan transferase and sucrose synthase mRNA levels were constant during all stages of growth.