Conservation of lotus and Arabidopsis basic helix-loop-helix proteins reveals new players in root hair development.
Basic helix-loop-helix (bHLH) proteins constitute a large family of transcriptional regulators in plants. Although they have been shown to play important roles in a wide variety of developmental processes, relatively few have been functionally characterized. Here, we describe the map-based cloning of the Lotus japonicus ROOTHAIRLESS1 (LjRHL1) locus. Deleterious mutations in this locus prevent root hair development, which also aborts root hair-dependent colonization of the host root by nitrogen-fixing bacteria. We show that the LjRHL1 gene encodes a presumed bHLH transcription factor that functions in a nonredundant manner to control root hair development in L. japonicus. Homology search and cross-species complementation experiments defined three members of the Arabidopsis (Arabidopsis thaliana) bHLH protein family, At2g24260, At4g30980, and At5g58010, as functionally equivalent to LjRHL1. Curiously, At2g24260 and At4g30980 mRNA species accumulate independently from the known positive regulators of root hair cell fate, while all three genes act in a partially redundant manner to regulate root hair development in Arabidopsis.
Karas
Bogumil
B
Agriculture and Agri-Food Canada, Southern Crop Protection and Food Research Centre, London, Ontario, Canada N5V 4T3.
Amyot
Lisa
L
Johansen
Christopher
C
Sato
Shusei
S
Tabata
Satoshi
S
Kawaguchi
Masayoshi
M
Szczyglowski
Krzysztof
K
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005816:Genetic Complementation Test; D000070116:Lotus / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D018517:Plant Roots / Q000254:growth & development*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D018744:DNA, Plant
Cell. 1999 Nov 24;99(5):473-83
10589676
J Exp Bot. 2001 Mar;52(Spec Issue):413-7
11326047
Trends Plant Sci. 2008 Oct;13(10):515-7
18762442
Dev Biol. 2004 Apr 15;268(2):506-13
15063185
EMBO J. 2002 Oct 1;21(19):5036-46
12356720
Plant Physiol. 2006 Aug;141(4):1167-84
16896230
Development. 2008 Apr;135(7):1335-45
18305006
Plant Physiol. 2007 Jun;144(2):538-49
17556517
Biochem J. 1971 Dec;125(4):1075-80
5144223
Development. 2005 Feb;132(3):603-14
15634699
Development. 2003 Dec;130(26):6431-9
14627722
Dev Biol. 1994 Dec;166(2):740-54
7813791
Nucleic Acids Res. 2002 Jan 1;30(1):94-7
11752264
Development. 2003 Oct;130(20):4859-69
12917293
Proc Natl Acad Sci U S A. 2001 Nov 20;98(24):13778-83
11717436
Science. 2007 Jan 5;315(5808):101-4
17110535
Plant J. 2008 Aug;55(3):504-13
18410479
Science. 2003 Aug 1;301(5633):653-7
12893945
Development. 1996 Apr;122(4):1253-60
8620852
J Bacteriol. 2007 Nov;189(22):8347-52
17827288
Plant Cell. 1999 Jul;11(7):1337-50
10402433
Mol Plant Microbe Interact. 2002 Jan;15(1):17-26
11843301
Science. 1997 Aug 22;277(5329):1113-6
9262483
Mol Biol Evol. 2003 May;20(5):735-47
12679534
Genetics. 2000 Nov;156(3):1349-62
11063707
Trends Plant Sci. 2006 Dec;11(12):601-9
17088095
J Exp Bot. 2007;58(14):3829-40
18162628
Science. 2007 Jun 8;316(5830):1477-80
17556585
Plant Physiol. 2005 Apr;137(4):1331-44
15778455
Annu Rev Plant Biol. 2008;59:519-46
18444906
Proc Natl Acad Sci U S A. 2000 Mar 28;97(7):3718-23
10737809
Mol Plant Microbe Interact. 2006 Oct;19(10):1082-91
17022172
Nature. 1993 May 6;363(6424):38-45
8479534
DNA Res. 2008 Aug;15(4):227-39
18511435
Annu Rev Plant Biol. 2008;59:365-86
18257710