The expression of genes coding for auxin carriers in different tissues and along the organ can explain variations in auxin transport and the growth pattern in etiolated lupin hypocotyls.
Novel cDNA clones encoding putative auxin influx and efflux carriers have been isolated and characterized from etiolated lupin (Lupinus albus L) hypocotyls. The full length of LaAUX1 and LaPIN1 and the partial length of LaPIN3 were obtained and the deduced amino acid sequence revealed a high degree of identity with the corresponding auxin carrier proteins from several species. The expression of these genes depended on the tissue, the hypocotyl zone and seedling age. LaAUX1 and LaPIN3 were expressed in stele and outer tissues, while LaPIN1 was restricted to the stele. From the above-mentioned results and taking into account the role proposed for the efflux carrier PIN1, it is suggested that LaPIN1 could mediate the basipetal auxin transport already described in this organ. LaAUX1 might facilitate auxin influx in the transport cells. The expression of the three genes decreased down the hypocotyl. The basipetally decreasing gradient in the expression of LaPIN1 coincides with previous results showing a similar gradient in the intensity and polarity of auxin transport. The decisive role ascribed to PIN1 in polar auxin transport due to its localization in the basal end of transporting cells and the existence of such a gradient in the expression of LaPIN1 support the hypothesis of a barrier effect (generated by decreasing auxin transport) previously proposed by our research group as being responsible for the auxin gradient, which controls the growth pattern in etiolated lupin hypocotyls.
Oliveros-Valenzuela
M Rocío
MR
Departamento de Biología Vegetal (Fisiología Vegetal), Facultad de Biología, Universidad de Murcia, Campus de Espinardo, 30100, Murcia, Spain.
Reyes
David
D
Sánchez-Bravo
José
J
Acosta
Manuel
M
Nicolás
Carlos
C
D000595:Amino Acid Sequence; D001692:Biological Transport / Q000235:genetics / Q000502:physiology; D015152:Blotting, Northern; D015139:Blotting, Southern; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018546:Hypocotyl / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D031297:Lupinus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D007210:Indoleacetic Acids; D010940:Plant Proteins
Nature. 2005 Jun 30;435(7046):1251-6
15988527
Plant Physiol. 1998 Aug;117(4):1473-86
9701602
Proc Natl Acad Sci U S A. 1988 Apr;85(8):2444-8
3162770
Plant Physiol. 2001 Jun;126(2):524-35
11402184
Nature. 2001 Sep 27;413(6854):425-8
11574889
Plant J. 2002 Nov;32(4):509-17
12445122
Plant Physiol. 2004 Jan;134(1):28-31
14730061
Plant Physiol. 1992 Sep;100(1):108-14
16652931
Planta. 2003 Nov;218(1):15-26
12905024
Nature. 2002 Feb 14;415(6873):806-9
11845211
EMBO J. 1996 May 1;15(9):2115-24
8641277
Cell. 2003 Nov 26;115(5):591-602
14651850
J Plant Physiol. 2007 Jul;164(7):851-60
16904231
Plant Cell. 2004 Jul;16(7):1898-911
15208397
Plant Cell. 2002 Mar;14(3):589-97
11910006
Physiol Plant. 2004 Jun;121(2):294-304
15153197
Planta. 1987 Feb;170(2):168-80
24232875
Planta. 1991 Oct;185(3):391-6
24186424
Plant Physiol. 1997 May;114(1):295-305
9159952
Cell. 1996 Apr 19;85(2):183-94
8612271
Plant Physiol. 1998 Feb;116(2):455-62
9489005
Plant Physiol. 2001 Jun;126(2):536-48
11402185
Science. 1998 Dec 18;282(5397):2226-30
9856939
Genes Dev. 2001 Oct 15;15(20):2648-53
11641271
Plant Cell. 2007 Jan;19(1):131-47
17237354
Plant Physiol. 1992 Jul;99(3):808-11
16669004
Nature. 2003 Jun 26;423(6943):999-1002
12827205
Planta. 2003 Jan;216(3):366-76
12520327
J Theor Biol. 1988 Oct 21;134(4):547-59
3255010