Environmental Conditions During Wheat Grain Development Alter Temporal Regulation of Major Gluten Protein Genes

Abstract

ABSTRACTThe accumulation of transcripts for the major gluten storage proteins was assessed during grain development in wheat plants (Triticum aestivum L. ‘Butte 86’) grown under seven controlled environments where temperature, water, and fertilizer conditions were varied after anthesis. Transcripts within the α‐, γ‐ and ω‐gliadin, low molecular weight glutenin subunit (LMW‐GS), and high molecular weight glutenin subunit (HMW‐GS) gene families followed similar patterns of accumulation throughout grain development under each environmental regimen. Under moderate daytime temperatures in plants that were well watered and fertilized, transcripts from all gene families were detectable by eight days postanthesis (8 DPA), were present at high levels until ≈34 DPA, and disappeared between 36 and 38 DPA. Under high temperature regimens, transcripts from all gene families appeared slightly earlier, but the time frame of accumulation was shorter. The presence or absence of postanthesis fertilizer did not alter the temporal regulation of the gluten genes under the moderate temperature regimen. However, under the high daytime temperature regimen, transcripts disappeared slightly earlier in kernels from plants that did not receive postanthesis fertilizer. Reverse transcriptase polymerase chain reaction (RT‐PCR) using primer pairs for specific HMW‐GS and LMW‐GS transcripts revealed that individual genes within each family exhibited identical patterns of temporal regulation under different environmental conditions.