Relationship Between Dehydrin Accumulation and Winter Survival in Winter Wheat and Barley Grown in the Field

Abstract

Low temperatures represent a crucial environmental factor determining winter survival (WS) of barley and wheat winter-type varieties. In laboratory experiments, low temperatures induce an active plant acclimation response, which is associated with an enhanced accumulation of several stress-inducible proteins including dehydrins. Here, dehydrin accumulations in sampled wheat (WCS120 protein family, or WCS120 and WDHN13 transcripts) and barley (DHN5 protein) varieties grown in two locations for two winters were compared with the variety WS evaluated by a provocation wooden-box test. A high correlation between dehydrin transcripts or protein relative accumulation and variety WS score was found only in samples taken prior vernalization fulfillment, when high tolerant varieties accumulated dehydrins earlier and to higher level than less tolerant varieties, and the plants have not yet been vernalized. After vernalization fulfillment, the correlation was weak, and the apical development indicated that plants reached double ridge (DR) in barley or stayed before DR in wheat. Dehydrin proteins and transcripts can be thus used as reliable markers of wheat or barley variety winter hardiness in the field conditions; however, only at the beginning of winter, when the plants have not yet finished vernalization. In wheat, a higher correlation was obtained for the total amount of dehydrins than for the individual dehydrin proteins.

Highlights: -More tolerant winter-type wheat and barley plants reveal higher threshold induction temperatures for dehydrin accumulation in comparison to less tolerant varieties. Thus, more tolerant winter cereals have higher dehydrin levels than the less tolerant ones upon the same ambient temperature in November samplings.-A significant correlation between dehydrin transcript/protein accumulation and winter survival was found in both winter wheat and winter barley plants in the field conditions, but only prior to vernalization fulfillment.

Keywords: apical development; dehydrins; field trials; vernalization; winter barley; winter survival; winter wheat.

FIGURE 1

Temperature and precipitation during winters 2013–2015 at two locations. (A) Winter 2013/14 in CRI- Prague, (B) winter 2014/15 in CRI- Prague, (C) winter 2013/14 in Selgen-Lužany, and (D) winter 2014/15 in Selgen-Lužany. Arrow indicates date of the sampling.

FIGURE 2

Development of shoot apex and days to heading evaluated in greenhouse for wheat Bohemia and barley Saffron sampled from field during two winters (2013/2014 and 20104/2015). Error bars indicate SD, different letters indicate significant differences at 0.05 level using ANOVA analysis followed by Duncan’s multiple range test. Decimal code 20 indicates the double ridge stage (see more in the methods).

FIGURE 3

Representative visualization of (A) immunoblot of barley and wheat dehydrins extracted from crowns sampled on January 2014. (B) The visualization of sample load (cut of the same membrane stained by Ponceau S). Order of the samples from left to right – St-Fabian-V – mixture from all three biological replicates, Kaylin 2nd biological replicate, Kaylin, Travira, Fabian, Lancelot, Fridericus, Saffron, Sylva, Lancelot, Saffron, Kaylin, Fabian, Fridericus, Saffron 2nd biological replicate, Bohemia, Sultan, Dulina, Aranka, Bohemia 2nd biological replicate. Abbreviations: L – samples from SELGEN, Lužany; MW – ALL Blue Precision Plus Protein Standards (Bio-Rad); St – standard for gel normalization of quantity; V – samples from CRI, Prague.

FIGURE 4

Relationships between winter survival and (A) accumulation of DHN5 in barley, (B) accumulation of dehydrins in wheat. Asterisk marks significant correlation coefficient R (P ≤ 0.05). Dec, December samplings; Jan, January samplings; Nov, November; WS, winter survival.

FIGURE 5

Relationships between WS and (A) normalized relative gene expression of WDHN13 transcript and (B) normalized relative gene expression of WCS120 transcript in wheat. Asterisk marks significant correlation coefficient R (P ≤ 0.05). Abbreviations: Jan, January samplings; Nov, November samplings; WS, winter survival.