QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online 30 March 2005
doi: 10.1242/dev.01815

This Article Summary Full Text Full Text (PDF) Supplementary Material Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Norberg, M. Articles by Nilsson, O. Search for Related Content PubMed PubMed Citation Articles by Norberg, M. Articles by Nilsson, O. Social Bookmarking                         What's this?

The BLADE ON PETIOLE genes act redundantly to control the growth and development of lateral organs

Mikael Norberg^*, Mattias Holmlund^* and Ove Nilsson

Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-90183 Umeå, Sweden

View larger version (67K): [in a new window]   Fig. 1. Molecular characterization of BOP1 and BOP2. (A) Genomic structure (left) and BOP1 and BOP2 expression in the various mutant alleles compared with wild type (right). Dark-shaded boxes are exons, light-shaded boxes are 5' untranslated regions. Black arrows show translational start sites. Triangles mark the T-DNA insertion sites in the various mutant alleles. 4 x 35S indicates the four 35S enhancers present in the activation-tagging T-DNA. The expression levels of BOP1 and BOP2 in the mutants and wild type were quantified by RT-PCR with 18S ribosomal RNA used as control. The BOP1 expression in bop1-6D was detected with northern blot. (B) Alignment of predicted amino-acid sequences of BOP1, BOP2 and NPR1, with BTB/POZ domains and ankyrin-repeats (ANK) indicated. Identical residues between all three proteins are shaded in black, residues that are identical in at least two sequences are shaded in grey. (C) Phylogenetic interrelationship of all Arabidopsis proteins predicted to contain BTB/POZ domains followed by ANK repeats. The At3g43700 gene contains only the BTB/POZ domain and has been used as an outgroup. Bootstrap support values are indicated.

View larger version (122K): [in a new window]   Fig. 2. Phenotypes of bop1 and bop1 bop2 mutants. (A) Ectopic leaf formed from the petiole of a bop1-5 mutant plant grown in short days. (B) 24-day-old Col-0 wild-type plant (left) and bop1-5 bop2-2 double mutant plant (right). (C) Growth and development of leaf 1 and 2 from Col-0 wild type (left) and bop1-5 bop2-2 (right) from day 7 to day 22 after germination. Scale bar: 1 cm. (D,E) Inflorescences of Col-0 wild type (D) and a bop1-5 bop2-2 double mutant (E). Arrowheads point to bracts subtending the flowers. (F,G) Flowers of Col-0 wild type (F) and a bop1-5 bop2-2 double mutant (G). Arrowheads point to stipules growing from the base of the bract. Inset in G is a magnification of the proximal part of the bract. Scale bars: 1 mm. (H) Phenotypes of plants grown in short days. From left to right: Col-0 wild type (2 months old), bop1-5 bop2-2 double mutant (2 months old) and bop1-5 bop2-2 double mutant (5 months old). (I-K) Floral organ abscission in wild type (I) and bop1-5 bop2-2 double mutant (J,K). While wild type abscise their flower organs at an early stage (I), bop1-5 bop2-2 double mutants never abscise their flower organs (J,K). Scale bars: 1 cm. (K) Dry silique from a bop1-5 bop2-2 double mutant plant after dehiscence of seeds. The large arrowhead indicates the dry floral organs that are still attached. The small arrowhead (b) points to a bract that is delayed in senescence compared with the sepals.

View larger version (184K): [in a new window]   Fig. 6. Ectopic expression of JAG in bop mutants. JAG (A,C,D) and BOP2 (B) expression, as determined by in situ hybridization. (A-C) Vegetative shoot apex from 11-day-old wild-type (A,B) and bop1-5 bop2-2 (C) plants. (A) JAG is expressed in the distal parts of leaf primordia (brackets). (B) BOP2 is expressed in the proximal parts of leaf primordia (bracket). (C) In bop1-5 bop2-2, JAG is ectopically expressed in the whole leaf primordium (brackets). (D) Section through a bop1-5 bop2-2 flower. JAG shows a uniform expression in the bract (arrowhead). Scale bars: 100 µm.

View larger version (137K): [in a new window]   Fig. 4. Expression of BOP1 and BOP2. (A,B) BOP2 expression in Col-0 wild type as determined by in situ hybridization. (A) Vegetative shoot apex from an 11-day-old plant. BOP2 is expressed in the incipient leaf primordia (ip) and in the proximal regions of emerging leaves (arrowheads). Scale bar: 100 µm. (B) BOP2 expression in the inflorescence apex. Expression can be seen in the incipient flower primordium (fp) and in the proximal parts of developing flower organs (arrowhead). Scale bar: 100 µm. (C-I) Expression of BOP1::GUS. (C-E) 5-day-old seedling. (C) BOP1 expression can be found in the proximal parts of leaf 1 and 2 and at the base of the cotyledons. (D) Histological section showing BOP1 expression in the proximal margins of leaf primordia. (E) BOP1 is expressed along the midveins of leaf 1 and 2, and along the cotyledon petioles. (F,G) 10-day-old seedling. BOP1 is expressed at the base of the petioles. In G, young leaves have been removed for clarity. (H) Section of an inflorescence apex showing BOP1 expression in proximal parts of developing flower organs. Scale bar: 100 µm. (I) Inflorescence showing BOP1 expression overlapping the flower organ abscission zone (az) and at the base of the pedicels (arrowhead). The base of the indicated pedicel has been magnified (inset) to show the BOP1 expression.

View larger version (64K): [in a new window]   Fig. 3. Phenotypes of bop1-6D, 35S::BOP1 and 35S::BOP2 plants. (A) bop1-6D mutant plant. (B) bop1-6D inflorescence. (C) 35S::BOP2 plant (D) 35S::BOP2 inflorescence. Note the clusters of paraclades and flowers formed from the same node and the similarity between the bop1-6D and 35S::BOP2 phenotypes. (E) 16-day-old wild-type plant. Scale bar: 1 cm. (F) 16-day-old 35S::BOP1 plant. Note the reduction in leaf size. Scale bar: 1 cm. (G) 35S::BOP1 inflorescence carrying very small flowers with reduced organ size. Scale bar: 2 mm. (H) Extreme phenotype of a 30-day-old 35S::BOP2 plant. Cot, cotyledon. Scale bar: 1 mm.

View larger version (34K): [in a new window]   Fig. 5. The BOP genes repress the expression of JAG and JGL. Gene expression was analyzed using quantitative RT-PCR. Results were normalized to the expression of 18S ribosomal RNA, then to the value of the wild-type control that was arbitrarily set to 1. Bars represent standard deviation of the mean for three separate biological replicates. (A,C) Relative expression levels of JAG (A) and JGL (C) in leaf 1 and 2 (left) and apical shoots (right) of 11-day-old Col-0 wild-type and bop1-5 bop2-2 mutant plants. (B,D) Relative expression levels of JAG (B) and JGL (D), in leaf 1 and 2 (left) and apical shoots (right) of 8-day-old Col-0 wild-type and bop1-6D mutant plants.

View larger version (92K): [in a new window]   Fig. 7. The BOP genes and LFY cooperate in the suppression of bract formation. (A) bop1-5 bop2-2 jag-1 flower with bract (arrowhead). (B) lfy-12 flower-like structure with bract (arrowhead). (C) bop1-5 bop2-2 lfy-12 flower-like structures with bracts (arrowheads). (D) Comparison of typical bracts from, from left to right: bop1-5 bop2-2, lfy-12 and bop1-5 bop2-2 lfy-12 mutants. Scale bar: 1 mm.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

Twitter