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A genotypic difference in primary root length is associated with the inhibitory role of transforming growth factor‐beta receptor‐interacting protein‐1 on root meristem size in wheat
Author(s) -
He Xue,
Fang Jingjing,
Li Jingjuan,
Qu Baoyuan,
Ren Yongzhe,
Ma Wenying,
Zhao Xueqiang,
Li Bin,
Wang Daowen,
Li Zhensheng,
Tong Yiping
Publication year - 2014
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.12449
Subject(s) - meristem , biology , arabidopsis , point of delivery , brassinosteroid , microbiology and biotechnology , gene , botany , genetics , mutant
Summary Previously we identified a major quantitative trait locus ( QTL ) qTaLRO‐B1 for primary root length ( PRL ) in wheat. Here we compare proteomics in the roots of the qTa LRO ‐B1 QTL isolines 178A, with short PRL and small meristem size, and 178B, with long PRL and large meristem size. A total of 16 differentially expressed proteins were identified: one, transforming growth factor ( TGF )‐beta receptor‐interacting protein‐1 (Ta TRIP 1), was enriched in 178A, while various peroxidases ( POD s) were more abundantly expressed in 178B. The 178A roots showed higher Ta TRIP 1 expression and lower levels of the unphosphorylated form of the brassinosteroid ( BR ) signaling component BZR 1, lower expression of POD genes and reduced POD activity and accumulation of the superoxide anion O 2 − in the root elongation zone compared with the 178B roots. Low levels of 24‐epibrassinolide increased POD gene expression and root meristem size, and rescued the short PRL phenotype of 178A. Ta TRIP 1 directly interacted with the BR receptor Ta BRI 1 of wheat. Moreover, overexpressing Ta TRIP 1 in Arabidopsis reduced the abundance of unphosphorylated BZR 1 protein, altered the expression of BR ‐responsive genes, inhibited POD activity and accumulation of the O 2 − in the root tip and inhibited root meristem size. Our data suggested that Ta TRIP 1 is involved in BR signaling and inhibited root meristem size, possibly by reducing POD activity and accumulation of O 2 − in the root tip. We further demonstrated a negative correlation between the level of Ta TRIP 1 m RNA and PRL of landraces and modern wheat varieties, providing a valuable insight for better understanding of the molecular mechanism underlying the genotypic differences in root morphology of wheat in the future.