TY - JOUR
T1 - Mitogen-activated protein kinase kinase 3 regulates seed dormancy in barley
AU - Nakamura, Shingo
AU - Pourkheirandish, Mohammad
AU - Morishige, Hiromi
AU - Kubo, Yuta
AU - Nakamura, Masako
AU - Ichimura, Kazuya
AU - Seo, Shigemi
AU - Kanamori, Hiroyuki
AU - Wu, Jianzhong
AU - Ando, Tsuyu
AU - Hensel, Goetz
AU - Sameri, Mohammad
AU - Stein, Nils
AU - Sato, Kazuhiro
AU - Matsumoto, Takashi
AU - Yano, Masahiro
AU - Komatsuda, Takao
N1 - Funding Information:
We thank N. Shibuya (Meiji University) for advice on kinase assay experiments; J. Pohl (IPK) for screening TILLING mutants; H. Sasaki (NIAS) and S. Mori (NIAS) for sequence assembly; J.L. Molina-Cano (IRTA) for providing us Triumph grains; J. Valkoun (ICARDA) for providing us grains of the wild barley accessions; F. Abe (NICS) and Y. Nagamura (NIAS) for supporting our experiments; and R.R. Finkelstein (UCSB) and Y. Ogihara (Kihara Institute for Biological Research) for critical reading of the manuscript. Part of barley accessions was provided by the Institute of Plant Science and Resources, Okayama University, with support in part by the National Bio-Resource Project of MEXT, Japan. This research was financially supported by a grant from the Japanese Ministry of Agriculture, Forestry and Fisheries (Genomics for Agricultural Innovation, TRC-1002, TRG-1002, and Genomics based Technology for Agriculture Improvement, TRS-1001).
Publisher Copyright:
© 2016 Elsevier Ltd All rights reserved.
PY - 2016/3/21
Y1 - 2016/3/21
N2 - Seed dormancy has fundamental importance in plant survival and crop production; however, the mechanisms regulating dormancy remain unclear [1-3]. Seed dormancy levels generally decrease during domestication to ensure that crops successfully germinate in the field. However, reduction of seed dormancy can cause devastating losses in cereals like wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) due to pre-harvest sprouting, the germination of mature seed (grain) on the mother plant when rain occurs before harvest. Understanding the mechanisms of dormancy can facilitate breeding of crop varieties with the appropriate levels of seed dormancy [4-8]. Barley is a model crop [9, 10] and has two major seed dormancy quantitative trait loci (QTLs), SD1 and SD2, on chromosome 5H [11-19]. We detected a QTL designated Qsd2-AK at SD2 as the single major determinant explaining the difference in seed dormancy between the dormant cultivar "Azumamugi" (Az) and the non-dormant cultivar "Kanto Nakate Gold" (KNG). Using map-based cloning, we identified the causal gene for Qsd2-AK as Mitogen-activated Protein Kinase Kinase 3 (MKK3). The dormant Az allele of MKK3 is recessive; the N260T substitution in this allele decreases MKK3 kinase activity and appears to be causal for Qsd2-AK. The N260T substitution occurred in the immediate ancestor allele of the dormant allele, and the established dormant allele became prevalent in barley cultivars grown in East Asia, where the rainy season and harvest season often overlap. Our findings show fine-tuning of seed dormancy during domestication and provide key information for improving pre-harvest sprouting tolerance in barley and wheat.
AB - Seed dormancy has fundamental importance in plant survival and crop production; however, the mechanisms regulating dormancy remain unclear [1-3]. Seed dormancy levels generally decrease during domestication to ensure that crops successfully germinate in the field. However, reduction of seed dormancy can cause devastating losses in cereals like wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) due to pre-harvest sprouting, the germination of mature seed (grain) on the mother plant when rain occurs before harvest. Understanding the mechanisms of dormancy can facilitate breeding of crop varieties with the appropriate levels of seed dormancy [4-8]. Barley is a model crop [9, 10] and has two major seed dormancy quantitative trait loci (QTLs), SD1 and SD2, on chromosome 5H [11-19]. We detected a QTL designated Qsd2-AK at SD2 as the single major determinant explaining the difference in seed dormancy between the dormant cultivar "Azumamugi" (Az) and the non-dormant cultivar "Kanto Nakate Gold" (KNG). Using map-based cloning, we identified the causal gene for Qsd2-AK as Mitogen-activated Protein Kinase Kinase 3 (MKK3). The dormant Az allele of MKK3 is recessive; the N260T substitution in this allele decreases MKK3 kinase activity and appears to be causal for Qsd2-AK. The N260T substitution occurred in the immediate ancestor allele of the dormant allele, and the established dormant allele became prevalent in barley cultivars grown in East Asia, where the rainy season and harvest season often overlap. Our findings show fine-tuning of seed dormancy during domestication and provide key information for improving pre-harvest sprouting tolerance in barley and wheat.
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U2 - 10.1016/j.cub.2016.01.024
DO - 10.1016/j.cub.2016.01.024
M3 - Article
C2 - 26948880
AN - SCOPUS:84959293507
VL - 26
SP - 775
EP - 781
JO - Current Biology
JF - Current Biology
SN - 0960-9822
IS - 6
ER -