Proteomic analysis of temperature dependency
of buckwheat seed dormancy and quality degradation
Akiko Hashiguchi
.
Hiroyuki Yoshioka
.
Setsuko Komatsu
Received: 6 September 2017 / Accepted: 4 April 2018 / Published online: 24 May 2018
Ó Brazilian Society of Plant Physiology 2018
Abstract Buckwheat is a functional staple food,
which is rich in rutin and other flavonoids with strong
antioxidant potential. However, the quality of buck-
wheat grain is easy to degrade during storage and low
temperature is better to keep the flavor and texture. We
tested the hypothesis that the quality degradation is
related to seed dormancy which is lost at a rate in
temperature-dependent manner in most seeds. To
understand physiological processes in seeds under
temperature stress, which affects quality of stored
buckwheat grain, a gel-free/label-free proteomic anal-
ysis was conducted. Compared to the seeds before
storage, a total of 30, 76, 52, 14, and 61 proteins were
affected at 5 °C for 5 months, 5 °C for 10 months,
15 °C for 5 months, 15 °C for 10 months, and 25 °C
for 5 months, respectively. Functional classification
revealed that storage condition at 5 °C for 5 months
resulted in different protein profile from other condi-
tions and suitable for keeping best condition. Storage
at higher temperature for longer time influenced
proteins related to preparation for emergence by
carbohydrate metabolism, endogenous gene expres-
sion, and protein homeostasis. Proteins such as
granule-bound starch synthase and 13S seed storage
protein consistently decreased in abundance during
storage. These results suggest that stored buckwheat
seeds experience seed dormancy release, but the
processes are not clear in relation to temperature rise.
Dormancy break is recognized but emergence is
inhibited by abscisic acid, which was induced by
temperature stress, showing the complexity of buck-
wheat germination control. The quality degradation of
stored seeds might be due to changed starch compo-
sition and protein network.
Keywords Proteomic analysis Á Buckwheat Á
Storage Á Temperature stress Á Seed dormancy
Abbreviations
LC Liquid chromatography
MS Mass spectrometry
CHO Carbohydrate
GAPDH Glyceraldehyde-3-phosphate
dehydrogenase
FBPA Fructose-bisphosphate aldolase
Electronic supplementary material The online version of
this article (https://doi.org/10.1007/s40626-018-0104-7) con-
tains supplementary material, which is available to authorized
users.
A. Hashiguchi
Faculty of Medicine, University of Tsukuba,
Tsukuba 305-8572, Japan
H. Yoshioka (&)
Development Head Office, Kumamoto Flour Milling Co.
Ltd, Hanazono 1-25-1, Kumamoto 860-8625, Japan
e-mail: h-yoshioka@bears-k.co.jp
S. Komatsu (&)
Faculty of Life and Environmental Sciences, University of
Tsukuba, Tennodai 1-1-1, Tsukuba 305-8572, Japan
e-mail: komatsu.setsuko.fu@u.tsukuba.ac.jp
123
Theor. Exp. Plant Physiol. (2018) 30:77–88
https://doi.org/10.1007/s40626-018-0104-7
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