Abstract:

High molecular weight glutenin subunit (HMW-GS) and glutenin macropolymer (GMP) play key roles in determining grain quality in wheat (Triticum aestivum L.). The aim of this study was to evaluate effects of drought and waterlogging post anthesis on HMW-GS and GMP contents in grains of two wheat cultivars, Yumai 34 (strong gluten) and Yumai 9(weak gluten). According to our previously reported quantification protocol, each HMW-GS content was calorimetrically determined, following the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The treatments of waterlogging, drought, and moderate water supply (CK) were used from anthesis to maturity. The results showed that HMW-GS of both cultivars under drought and those of Yumai 34 under waterlogging appeared in grains at about 10 days post anthesis (DPA), while those of Yangmai 9 under waterlogging and of both cultivars under moderate water supply were firstly found at about 15 DPA. The results indicated that water stress post anthesis showed significantly negative impact on the formation of HMW-GS in grains of both cultivars, and drought enhanced the initial formation of HMW-GS in grains of both cultivars. Compared with the control, drought promoted the HMW-GS accumulation at early grain filling stage, while the case was just opposite at late grain filling stage. Waterlogging showed more obviously negative impact on HMW-GS and GMP accumulation than drought. Finally, the control had the highest total HMW-GS and GMP contents, followed by drought treatment, and waterlogging was the lowest for both wheat cultivars. Under the same water treatment, each HMW-GS content of grains was higher in Yumai 34 than in Yangmai 9.

Key words: Wheat, Drought, Waterlogging, High molecular weight glutenin subunits (HMW-GS), Glutenin macropolymer (GMP)