Diurnal Expression Pattern, Allelic Variation, and Association Analysis Reveal Functional Features of the E1 Gene in Control of Photoperiodic Flowering in Soybean.
Although four maturity genes, E1 to E4, in soybean have been successfully cloned, their functional mechanisms and the regulatory network of photoperiodic flowering remain to be elucidated. In this study, we investigated how the diurnal expression pattern of the E1 gene is related to photoperiodic length; and to what extent allelic variation in the B3-like domain of the E1 gene is associated with flowering time phenotype. The bimodal expression of the E1 gene peaked first at around 2 hours after dawn in long-day condition. The basal expression level of E1 was enhanced by the long light phase, and decreased by duration of dark. We identified a 5bp (3 SNP and 2-bp deletion) mutation, referred to an e1-b3a, which occurs in the middle of B3 domain of the E1 gene in the early flowering cultivar Yanhuang 3. Subcellular localization analysis showed that the putative truncated e1-b3a protein was predominately distributed in nuclei, indicating the distribution pattern of e1-b3a was similar to that of E1, but not to that of e1-as. Furthermore, genetic analysis demonstrated allelic variations at the E1 locus significantly underlay flowering time in three F2 populations. Taken together, we can conclude the legume specific E1 gene confers some special features in photoperiodic control of flowering in soybean. Further characterization of the E1 gene will extend our understanding of the soybean flowering pathway in soybean.
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China.
Hong
H
Zhai
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, China.
Shixiang
S
Lü
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China.
Hongyan
H
Wu
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, China.
Yupeng
Y
Zhang
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, China.
Xingzheng
X
Zhang
Huaiyin Institute of Agricultural Sciences of Xuhuai Region in Jiangsu, Huaian, China.
Jiayin
J
Yang
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, China.
Yaying
Y
Wang
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China.
Guang
G
Yang
Soybean Research Institute, Jilin Academy of Agricultural Sciences, Changchun, China.
Hongmei
H
Qiu
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China.
Tingting
T
Cui
Key Laboratory of Soybean Molecular Design Breeding, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China.
Zhengjun
Z
Xia
D000483:Alleles; D035264:Flowers / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D017343:Genes, Plant / Q000502:physiology*; D014644:Genetic Variation; D017440:Photoperiod; D013025:Glycine max / Q000235:genetics / Q000378:metabolism