TY - JOUR

T1 - Structural and functional divergence of the Mpc1 genes in wheat and barley

AU - Strygina, Ksenia V.

AU - Khlestkina, Elena K.

PY - 2019/2/26

Y1 - 2019/2/26

N2 - Background: The members of the Triticeae tribe are characterised by the presence of orthologous and homoeologous gene copies regulating flavonoid biosynthesis. Among transcription factors constituting a regulatory MBW complex, the greatest contribution to the regulation of flavonoid biosynthetic pathway is invested by R2R3-Myb-type TFs. Differently expressed R2R3-Myb copies activate the synthesis of various classes of flavonoid compounds in different plant tissues. The aim of this research was the identification, comparison and analysis of full-length sequences of the duplicated R2R3-Myb Mpc1 (Myb protein c1) gene copies in barley and wheat genomes. Results: The Mpc1 genes were identified in homoeologous group 4 and 7 chromosomes: a total of 3 copies in barley (Hordeum vulgare L.) and 8 copies in bread wheat (Triticum aestivum L.) genomes. All Mpc1 genes have a similar two-exon structure, and almost all of them are transcriptionally active. The calculation of the divergence time revealed that first duplication between 4 and 7 chromosomes of the common ancestor of the Triticeae tribe occurred about 35-46 million years ago (MYA); the last duplication arised about 16-19 MYA before the divergence Triticum and Hordeum genera The connection between gene expression and the appearance of anthocyanin pigmentation was found for three genes from homoeologous group 4 chromosomes: TaMpc1-A2 (5AL) in wheat coleoptile, HvMpc1-H2 (4HL) in barley lemma and aleurone layer, and HvMpc1-H3 (4HL) in barley aleurone layer. TaMpc1-D4 (4DL) from the wheat genome showed a strong level of expression regardless of the colour of coleoptile or pericarp. It is assumed, that this gene regulates the biosynthesis of uncoloured flavonoids in analysed tissues. Conclusions: The regulatory R2R3-Myb genes involved in anthocyanin synthesis were identified and characterised in Triticeae tribe species. Genes designated HvMpc1-H2 and HvMpc1-H3 appeared to be the main factors underlying intraspecific variation of H. vulgare by lemma and aleurone colour. TaMpc1-A2 is the co-regulator of the Mpc1-1 genes in bread wheat genome controlling anthocyanin synthesis in coleoptile.

AB - Background: The members of the Triticeae tribe are characterised by the presence of orthologous and homoeologous gene copies regulating flavonoid biosynthesis. Among transcription factors constituting a regulatory MBW complex, the greatest contribution to the regulation of flavonoid biosynthetic pathway is invested by R2R3-Myb-type TFs. Differently expressed R2R3-Myb copies activate the synthesis of various classes of flavonoid compounds in different plant tissues. The aim of this research was the identification, comparison and analysis of full-length sequences of the duplicated R2R3-Myb Mpc1 (Myb protein c1) gene copies in barley and wheat genomes. Results: The Mpc1 genes were identified in homoeologous group 4 and 7 chromosomes: a total of 3 copies in barley (Hordeum vulgare L.) and 8 copies in bread wheat (Triticum aestivum L.) genomes. All Mpc1 genes have a similar two-exon structure, and almost all of them are transcriptionally active. The calculation of the divergence time revealed that first duplication between 4 and 7 chromosomes of the common ancestor of the Triticeae tribe occurred about 35-46 million years ago (MYA); the last duplication arised about 16-19 MYA before the divergence Triticum and Hordeum genera The connection between gene expression and the appearance of anthocyanin pigmentation was found for three genes from homoeologous group 4 chromosomes: TaMpc1-A2 (5AL) in wheat coleoptile, HvMpc1-H2 (4HL) in barley lemma and aleurone layer, and HvMpc1-H3 (4HL) in barley aleurone layer. TaMpc1-D4 (4DL) from the wheat genome showed a strong level of expression regardless of the colour of coleoptile or pericarp. It is assumed, that this gene regulates the biosynthesis of uncoloured flavonoids in analysed tissues. Conclusions: The regulatory R2R3-Myb genes involved in anthocyanin synthesis were identified and characterised in Triticeae tribe species. Genes designated HvMpc1-H2 and HvMpc1-H3 appeared to be the main factors underlying intraspecific variation of H. vulgare by lemma and aleurone colour. TaMpc1-A2 is the co-regulator of the Mpc1-1 genes in bread wheat genome controlling anthocyanin synthesis in coleoptile.

KW - Anthocyanin biosynthesis

KW - Flavonoid pigments

KW - Gene duplication

KW - Gene evolution

KW - Hordeum

KW - Myb

KW - Near-isogenic lines

KW - Transcription factor

KW - Triticum

KW - PROTEIN

KW - MYB TRANSCRIPTION FACTORS

KW - FAMILY

KW - FLAVONOID BIOSYNTHESIS

KW - EVOLUTION

KW - COLOR GENES

KW - BREAD WHEAT

KW - PLANTS

KW - REGULATORS

KW - DIVERSITY

UR - http://www.scopus.com/inward/record.url?scp=85062226628&partnerID=8YFLogxK

U2 - 10.1186/s12862-019-1378-3

DO - 10.1186/s12862-019-1378-3

M3 - Article

C2 - 30813913

AN - SCOPUS:85062226628

VL - 19

SP - 45

JO - BMC Evolutionary Biology

JF - BMC Evolutionary Biology

SN - 1471-2148

IS - Suppl 1

M1 - 45

ER -