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Triticeae Genomics and Genetics 2012, Vol.3, No.1, 1
-
8
http://tgg.sophiapublisher.com
1
A Letter Open Access
Analysis of Characteristics, Mutant Sites and Evolution of Dehydrin 6 (DHN6)
Protein in Three Types of Rowed Barleys
Maosheng Liu
1,2
, Qian Zhou
3
, Junjiao Ping
2
, Zhen Zhang
2
, Gang Qian
2
1. Department of Anatomy, Zunyi Medical College, Zunyi, 563099, P.R. China;
2. Department of Cell Biology and Genetics, Zunyi Medical College, Zunyi, 563099, P.R. China;
3. Department of Obstetrics and Gynecology, Affiliated Hospital, Zunyi Medical College, Zunyi, 563099, P.R. China
Corresponding author email:
pengjiaqiong@163.com;
Authors
Triticeae Genomics and Genetics, 2012, Vol.3, No.1 doi: 10.5376/tgg.2012.03.0001
Received: 10 Feb., 2012
Accepted: 12 Mar., 2012
Published: 13 Mar., 2012
This article was first published in Molecular Plant Breeding in Chinese, and here was authorized to translate and publish the paper in English under the terms of Creative
Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Liu et al., 2012, Analysis of Characteristics, Mutant Sites and Evolution of Dehydrin 6 (DHN6) Protein in Three Types of Rowed Barleys, Triticeae Genomics
and Genetics, Vol.3, No.1 1-8 (doi: 10.5376/tgg.2012.03.0001)
Abstract
Dehydrins (DHNs), a special polypeptide generated in late embryogenesis of higher plants, could protect the plants from
the damage caused by cell dehydration. In order to learn the relationship between characteristics and functions of dehydrins, we
cloned
Dhn
6 genes from three types of rowed barleys, and bioinformatics analysis showed that they encoded proteins composed of
523 (six-rowed barley), 502 (four-rowed barley) and 486 (two-rowed barley) amino acid residues, respectively. Furthermore, analysis
of amino acid mutations found that there were whole conservative traits and mutant sites specificity in this gene. Analyses of protein
characteristics and the secondary structure indicated that DHN6 was a highly hydrophilic alkaline protein, and linear structure and
numerous random curls were the main component of secondary structure. Moreover, K-segment was involved in the formation of the
α-helix, which presumed that the amphipathic α-helices domain of DHN6 might play important roles in protecting membrane
structure during the hydration process. The construction of phylogenetic tree of 21 species in this study showed that
Dhn
6 gene could
be an efficient foundation for identifying and distinguishing of different species associated with special sequences of nucleotides, and
had a closer genetic distance in Gramineae crops.
Keywords
Barley (
Hordeum vulgare
L.);
Dhn
6 gene; Sequence alignment; Secondary structure; Phylogenesis
Background
Water deficit, the most limiting factor of plant growth
and crop production, induces various biochemical and
physiological responses in plants (Kiani et al., 2007).
Plants respond to water deficit through multiple
physiological mechanisms at the cellular, tissue, and
whole-plant levels. These responses are not only
dependent on the severity and duration of the water
deficit, but also on the developmental stage and
morphological/anatomical parameter of the plants
(Ludlow and Muchow, 1990; Smith and Griffiths,
1993). Late embryogenesis abundant (LEA) proteins
were believed to play a significant role in the stress
response in various organisms including plants, algae,
yeasts and bacteria (Ramanjulu and Bartels, 2002).
Dehydins (DHNs), molecular weight 9~20 kD, are
among the most frequently observed proteins in plants
under water stress (Suprunova et al., 2004). In the
barley genome, recent investigations into dehydrin
multigene family have been identified 13
Dhn
genes,
which encode 4 sub classes of DHNs: Y
n
SK
n
, SK
n
, K
n
and KS, respectively, based on permutations in the
arrangement of characterized domains (Campbell and
Close, 1997; Werner-Fraczek and Close, 1998;
Rodriguez et al., 2005).
In a few studies, Garay-Arroyo et al (2000) and Qian
et al (2010) argued the review that amphipathic
α-helices formed by K-sequence could play an
important role in protecting membrane structure.
Association between tolerance to stresses involving
dehydration (drought, salinity or freezing) and
accumulation of members of the
Dhn
family has been
established in different species such as wheat, barley
poplar and sunflower (Giordani et al., 1999; Lopez et
al., 2003). Genetic variability in the stress response