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Three genomes differentially contribute to the seedling lateral root number in allohexaploid wheat: evidence from phenotype evolution and gene expression
Author(s) -
Wang Huifang,
Hu Zhaorong,
Huang Ke,
Han Yao,
Zhao Aiju,
Han Haiming,
Song Long,
Fan Chaofeng,
Li Run,
Xin Mingming,
Peng Huiru,
Yao Yingyin,
Sun Qixin,
Ni Zhongfu
Publication year - 2018
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14005
Subject(s) - biology , ploidy , genome , genetics , gene , common wheat , arabidopsis , aegilops tauschii , aegilops , botany , chromosome , mutant
Summary Common wheat is an allohexaploid ( BBAADD ) that originated from the hybridization and polyploidization of the diploid Aegilops tauschii ( DD ) with the allotetraploid Triticum turgidum ( BBAA ). Phenotypic changes often arise with the formation and evolution of allopolyploid wheat, but little is known about the evolution of root traits in different wheat species with varying ploidy levels. Here, we reported that the lateral root number on the primary root ( LRNPR ) of synthetic and natural allohexaploid wheats ( BBAADD ) is significantly higher than that of their allotetraploid ( BBAA ) and diploid ( AA and SS ) progenitors, but is much lower than that of their diploid ( DD ) progenitors. The expression of the wheat gene Ta LBD 16 , an ortholog of the Arabidopsis LATERAL ORGAN BOUNDARIES ‐ DOMAIN 16/ ASYMMETRIC LEAVES 2‐ LIKE 18 ( LBD 16 ), which is involved in lateral root development in Arabidopsis, was positively correlated with the LRNPR in diploid and allopolyploid wheats. In natural and synthetic allohexaploid wheats, the transcript of the Ta LBD 16 from the D genome ( Ta LBD 16‐D ) was relatively more abundant compared with Ta LBD 16‐A and Ta LBD 16‐B . Consistent with the observed variation in LRNPR , the divergence in the expression of Ta LBD 16 homoeologous genes occurred before the formation of polyploidy wheat. Collectively, our observations indicate that the D genome played a crucial role in the increased lateral root number of allohexaploid wheats compared with their allotetraploid progenitors, and that Ta LBD 16‐D was one of the key genes involved in the formation of lateral root number during wheat evolution.