A DNA element between At4g28630 and At4g28640 confers companion-cell specific expression following the sink-to-source transition in mature minor vein phloem

被引:20
作者
McGarry, Roisin C. [1 ]
Ayre, Brian G. [1 ]
机构
[1] Univ N Texas, Dept Biol Sci, Denton, TX 76203 USA
基金
美国国家科学基金会;
关键词
enhancer trap; minor vein phloem; sink-to-source transition;
D O I
10.1007/s00425-008-0786-1
中图分类号
Q94 [植物学];
学科分类号
071001 ;
摘要
The collection phloem in minor veins is distinct from other vein classes in that the minor veins mature during the sink to source transition and are the primary sites of phloem loading. After maturation, minor vein phloem maintains its character in part through minor-vein specific regulatory cascades; however despite its physiological significance, little of these developmental programs is understood. From an Arabidopsis enhancer trap screen, we identified MATURE MINOR VEIN ELEMENT1 (MMVE1) in the intergenic region between two oppositely oriented genes, the ABC transporter ATM1 (At4g28630) and IAA11 (At4g28640). MMVE1 promotes reporter gene activity in minor vein phloem in a pattern resembling the sink to source transition. Promoter truncation experiments and phylogenetic footprinting demonstrate sequences proximal to ATM1 promote minor vein expression whereas sequences closer to IAA11 repress it. Both orientations of the promoter were used to drive expression of CONSTANS to generate a phloem mobile signal conferring early flowering under non-inductive conditions. Tandem copies of MMVE1 increase minor vein expression strength and specificity. MMVE1 is the first minor vein enhancer characterized from a species that loads from the apoplast, and supports the presence of unique regulatory cascades operating in minor vein phloem.
引用
收藏
页码:839 / 849
页数:11
相关论文
共 54 条
[1]   THE PS-IAA4/5-LIKE FAMILY OF EARLY AUXIN-INDUCIBLE MESSENGER-RNAS IN ARABIDOPSIS-THALIANA [J].
ABEL, S ;
NGUYEN, MD ;
THEOLOGIS, A .
JOURNAL OF MOLECULAR BIOLOGY, 1995, 251 (04) :533-549
[2]   Systematics and phylogeny of the Brassicaceae (Cruciferae): an overview [J].
Al-Shehbaz, I. A. ;
Beilstein, M. A. ;
Kellogg, E. A. .
PLANT SYSTEMATICS AND EVOLUTION, 2006, 259 (2-4) :89-120
[3]  
[Anonymous], 1983, COLD SPRING HARBOR L
[4]   Construction of a specialized cDNA library from plant cells isolated by laser capture microdissection: toward comprehensive analysis of the genes expressed in the rice phloem [J].
Asano, T ;
Masumura, T ;
Kusano, H ;
Kikuchi, S ;
Kurita, A ;
Shimada, H ;
Kadowaki, K .
PLANT JOURNAL, 2002, 32 (03) :401-408
[5]  
Ausubel F. M., 2002, SHORT PROTOCOLS MOL
[6]   Graft transmission of a floral stimulant derived from CONSTANS [J].
Ayre, BG ;
Turgeon, R .
PLANT PHYSIOLOGY, 2004, 135 (04) :2271-2278
[7]   Functional and phylogenetic analyses of a conserved regulatory program in the phloem of minor veins [J].
Ayre, BG ;
Blair, JE ;
Turgeon, R .
PLANT PHYSIOLOGY, 2003, 133 (03) :1229-1239
[8]   Symplastic continuity between companion cells and the translocation stream: Long-distance transport is controlled by retention and retrieval mechanisms in the phloem [J].
Ayre, BG ;
Keller, F ;
Turgeon, R .
PLANT PHYSIOLOGY, 2003, 131 (04) :1518-1528
[9]  
BASKIN TI, 1992, PLANTA, V187, P405, DOI 10.1007/BF00195665
[10]   NEW PLANT BINARY VECTORS WITH SELECTABLE MARKERS LOCATED PROXIMAL TO THE LEFT T-DNA BORDER [J].
BECKER, D ;
KEMPER, E ;
SCHELL, J ;
MASTERSON, R .
PLANT MOLECULAR BIOLOGY, 1992, 20 (06) :1195-1197