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The maize ( Zea mays L.) roothairless3 gene encodes a putative GPI‐anchored, monocot‐specific, COBRA‐like protein that significantly affects grain yield
Author(s) -
Hochholdinger Frank,
Wen TsuiJung,
Zimmermann Roman,
ChimotMarolle Patricia,
Da Costa e Silva Oswaldo,
Bruce Wesley,
Lamkey Kendall R.,
Wienand Udo,
Schnable Patrick S.
Publication year - 2008
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/j.1365-313x.2008.03459.x
Subject(s) - biology , gene , mutant , oryza sativa , gene family , genetics , gene expression
Summary The rth3 ( roothairless 3 ) mutant is specifically affected in root hair elongation. We report here the cloning of the rth3 gene via a PCR‐based strategy (amplification of insertion mutagenized sites) and demonstrate that it encodes a COBRA‐like protein that displays all the structural features of a glycosylphosphatidylinositol anchor. Genes of the COBRA family are involved in various types of cell expansion and cell wall biosynthesis. The rth3 gene belongs to a monocot‐specific clade of the COBRA gene family comprising two maize and two rice genes. While the rice ( Oryza sativa ) gene OsBC1L1 appears to be orthologous to rth3 based on sequence similarity (86% identity at the protein level) and maize/rice synteny, the maize ( Zea mays L.) rth3‐like gene does not appear to be a functional homolog of rth3 based on their distinct expression profiles. Massively parallel signature sequencing analysis detected rth3 expression in all analyzed tissues, but at relatively low levels, with the most abundant expression in primary roots where the root hair phenotype is manifested. In situ hybridization experiments confine rth3 expression to root hair‐forming epidermal cells and lateral root primordia. Remarkably, in replicated field trials involving near‐isogenic lines, the rth3 mutant conferred significant losses in grain yield.