Dehydrin Expression and Drought Tolerance in Seven Wheat Cultivars

Abstract

The winter wheat (Triticum aestivum L.) producing region of the U.S. Pacific Northwest (PNW) is subject to periods of water deficit during sowing and grain filling. Improving the genetic adaptation of wheat to drought stress represents one of the main objectives of regional breeding programs. One biochemical response to dehydrative stress is the accumulation of a family of proteins called dehydrins, which are believed to protect membranes and macromolecules against denaturation. Although previous studies demonstrated the accumulation of dehydrins in drought‐stressed wheat, little was known about the relation of dehydrin expression to acquisition of drought tolerance in specific varieties adapted to the PNW. We characterized dehydrin accumulation during the exposure of seven cultivars (‘Connie’, ‘Gene’, ‘TAM105’, ‘Rod’, ‘Hiller’, ‘Rhode’, and ‘Stephens’) to progressive drought stress in four separate experiments. The objective was to identify differences in the nature or timing of dehydrin expression in these cultivars and to learn whether dehydrin expression was associated with the acquisition of stress tolerance during seedling development. Expression of a 24‐kDa dehydrin was observed in Connie, TAM105, and Gene after 4 d of stress and at subsequent sampling dates while no dehydrins were detected in nonstress control plants. Dehydrin expression was significantly delayed in the remaining cultivars. The presence of this dehydrin was related to acquisition of drought tolerance characterized by a greater maintenance of shoot dry matter production in Connie, TAM105, and Gene. Although the role of these proteins remains unknown, their association with stress tolerance suggests that dehydrins might be used to improve the adaptation to drought.

Influence of abiotic stresses on plant proteome and metabolome changes

“…Lopez and co-workers during their research found a correlation between the accumulation of dehydrin in seven winter wheat cultivars during the exposure to water deficit. Three of the tested cultivars showed a significantly enhanced expression of 24 kDa dehydrin in comparison with other genotypes (Lopez et al 2003). In control plants of other analyzed genotypes, the expression of these proteins was not detected.…”

Analysis of mRNA Levels of Ten Genes Under Water Stress in Triticum turgidum subsp. durum

“…A wheat dehydrin has been shown to increase dehydration tolerance in transgenic rice (Cheng et al, 2002). In addition, drought-induced accumulation of dehydrin proteins has been associated with drought tolerance in many plant species, especially annual crops (Close et al, 1993;Lopez et al, 2001;Lopez et al, 2003). DHNs have been extensively studied in barley, where a dispersed family of 12 Dhn genes was characterized (Choi et al, 1999;Zhu et al, 2000).…”

Effect of Polyethylene Glycol Induced Water Stress on Germination and Seedling Growth of Wheat (<i>Triticum aestivum</i>)

“…The average production of this crop in Bangladesh is low compared to other wheat growing countries because wheat is mainly grown under nonirrigated conditions during the dry winter (November to April) in Bangladesh (Hossain and Silva, 2013). Although the vast storage of soil moisture resulted from monsoon rain supports the plant growth favorably at the early stages of growth, the plant suffers from water stress at the reproductive stage when the residual soil moisture depletes (Lopez et al, 2003).…”