Stress- and development-induced expression of spliced and unspliced transcripts from two highly similar dehydrin 1 genes in V. riparia and V. vinifera

Abstract

Dehydrins are proteins that accumulate in vegetative tissues subjected to various dehydrating stress conditions such as cold, drought, and salinity and in seeds at later stages of embryogenesis. Here, we report on two highly identical dehydrin genes, DHN1a and DHN1b, in wild and cultivated grapes, Vitis riparia and Vitis vinifera, and their expression in different tissues and under different environmental conditions. The two genes and their transcripts can easily be distinguished by RT-PCR because DHN1b has an 18 bp deletion compared to DHN1a. V. riparia expressed only DHN1a; V. vinifera expressed both DHN1a and DHN1b. Spliced transcripts, DHN1-S, encoding a putative YSK(2)-type dehydrin were present in low amounts in control leaves, but in high amounts in buds and seeds. Unspliced transcripts, DHN1-U, accumulated to high levels in buds and seeds. Cold, drought, and ABA treatment increased accumulation of both DHN1-S and DHN1-U in leaves, whereas short-day treatment increased only DHN1-S. The possible relation of these results with the difference in freezing stress tolerance between V. riparia and V. vinifera is discussed.

A diurnally regulated dehydrin from Avicennia marina that shows nucleo-cytoplasmic localization and is phosphorylated by Casein kinase II in vitro

“…Dehydrins are thermostable, highly hydrophilic proteins that accumulate in vegetative plant tissues under drought or salt stress or in seeds during maturation drying [41]. They constitute a ubiquitous group of plant proteins that are found in lower plant families such as the cyanobacteria, algae as well as higher plants [1].…”

Alternative splicing in plant stress response

“…Experiments with overexpression of dehydrins in Arabidopsis improved stress tolerance in these plants (Puhakainen et al 2004). In Vitis, two genes encoding dehydrins were identified (DHN1a and DHN1b); they contain one intron producing two splice forms -fully spliced encoding for a full protein and its unspliced version (Xiao and Nassuth 2006). The unspliced form encodes for two short ORFs, each giving a truncated protein.…”

The Importance of Size and Disorder in the Cryoprotective Effects of Dehydrins

“…This protein appears to be a splice variant of YSK 2 mRNA whose transcription is up-regulated after cold stress (Xiao and Nassuth, 2006). K 2 represents a minimal dehydrin model that can be used to better understand the structure-function relationships of this family of proteins.…”