Amino acid substitutions of the limit dextrinase gene in barley are associated with enzyme thermostability |
| |
| Authors: | Xinquan Yang Sharon Westcott Xue Gong Evan Evans Xiao-Qi Zhang Reg C M Lance Chengdao Li |
| |
| Institution: | (1) National Natural Science Foundation of China, 83 Shuangqing Road, Haidian District, Beijing, 100085, China;(2) Department of Agriculture and Food, Agricultural Research Western Australia, South Perth, WA, 6151, Australia;(3) Tasmanian Institute of Agricultural Research, University of Tasmania, Private Bag 54, Hobart, TAS, 7001, Australia;(4) Western Australian State Agricultural Biotechnology Centre, Murdoch University, Murdoch, WA, 6051, Australia |
| |
| Abstract: | Limit dextrinase (LD) is a key enzyme in determining the malting quality. A survey of 60 barley varieties showed a wide range
of variation for the enzyme activity and thermostability. Galleon showed low enzyme activity and high thermostability while
Maud showed high activity and low thermostability. Alignment of the LD amino acid sequences of Galleon and Maud identified
seven amino acid substitutions Lys/Arg-102, Thr/Ala-233, Ser/Gly-235, Gly/Ala-298, Cys/Arg-415, Ala/Ser-885 and Gly/Cys-888.
Genetic diversity of LD was investigated using single strand conformation polymorphism based on the amino acid substitutions.
Only limited genetic variation was detected in the current malting barley varieties, although wide variation was observed
in the wider barley germplasm. The Thr/Ala-233 and Ala/Ser-885 substitutions were associated with enzyme thermostability (P < 0.0001), but no polymorphism was associated with the enzyme activity. This result was confirmed from further sequence analysis.
The results will provide a tool for understanding and selection of high LD thermostability. |
| |
| Keywords: | Debranching enzyme Malting quality SNP Thermostability Hordeum vulgare |
| 本文献已被 SpringerLink 等数据库收录！ |
|
