spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online February 2, 2004
doi: 10.1242/10.1242/dev.00993

Development 131, 915-922 (2004)
Published by The Company of Biologists 2004
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Weir, I.
Right arrow Articles by Davies, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Weir, I.
Right arrow Articles by Davies, B.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

CUPULIFORMIS establishes lateral organ boundaries in Antirrhinum

Irene Weir1,*, Jianping Lu1,*, Holly Cook1, Barry Causier1, Zsuzsanna Schwarz-Sommer2 and Brendan Davies1,{dagger}

1 Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, UK
2 Max-Planck Institut für Züchtungsforschung, Carl-von-Linné-Weg 10, 50829 Köln, Germany



View larger version (98K):

[in a new window]
  		Fig. 1. The early cup phenotype. (A,C) A wild-type embryo and seedling are shown for comparison. (B) Representative cup embryo, note the complete fusion between the two cotyledons. (D,E,H) Fused cotyledons can also be seen in seedlings. After a variable period of time, shoots emerge from the hypocotyl (arrow in E; magnified in F) and these shoots also develop cup-shaped tips. The emerging shoot shown in F is shown again after 1 day in G. Further shoots arise from the primary hypocotyl and from the new shoots themselves (arrow in H), to produce a small mass of abortive shoots, each topped by a single cup (H). Scale bar in C and D: 1 mm.

 


View larger version (80K):

[in a new window]
  		Fig. 2. The cup phenotype in escape shoots. Wild-type stem, leaf, flower, carpel and ovules are shown for comparison (A,E,I,K,M). After a highly variable period of time most cup plants produce an escape shoot, which is not topped by a cup but which shows a series of characteristic abnormalities. Fusions between adjacent petioles at nodes (B) and between adjacent leaves (C,F,G) are clearly visible in adult cup plants. The lack of side shoots and spiral of fused bracts in the inflorescence can be seen in mature plants (D), eventually leading to a loss of meristem organisation and fasciation (H). Occasionally flowers are formed (H,J), although these are deformed (J) and contain organ fusions (J,L). Adjacent ovules in cup mutants are also often fused (arrow in N). cup-1 mutant flowers are always female sterile and usually male sterile. Scale bars in M and N: 0.1 mm.

 


View larger version (30K):

[in a new window]
  		Fig. 3. Isolation of the CUP gene. (A) Only one of the isolated Antirrhinum NAC-domain genes belonged to the same clade as CUC1, CUC2 and NAM (shaded). Other Arabidopsis NAC-domain proteins are included for comparison. Accession numbers are: NAP, CAA10955; CUC1, BAB20598; CUC2, BAA19529; NAM, CAA63101; CUP, AJ568269; GRAB2, CAA09372; CUC3, AAP82630; AtNAC1, AAF21437; and GRAB1, CAA09371. The tree was constructed by the neighbour-joining method in MacVector, using only the conserved NAC-domains. Bootstrap values are indicated. (B) The CUP gene consists of three exons. Untranslated transcribed regions are shown in grey and the conserved NAC-domain is stippled. The transposon insertion sites are shown for each allele. DNA sequence analysis of PCR products spanning the insertion sites indicated that the transposons were related to Tam-1 (cup-1) (Nacken et al., 1991Go) and Tam-4 (cup-2) (Luo et al., 1991Go), respectively. (C) Northern blot hybridised with a truncated CUP probe, lacking the NAC-domain, shows expression in the wild-type control but not in the two cup alleles. Stripping and re-hybridisation of the northern with a constitutive GAPDH probe demonstrates that RNA is present in each lane.

 


View larger version (113K):

[in a new window]
  		Fig. 4. CUP expression. (A) CUP expression in a young seedling is restricted to a band of cells between the vegetative apex and the young leaves (arrows). (B) A longitudinal section through the inflorescence apex shows CUP expression separating the developing bracts from the centre of the SAM. (C) A late stage 3 flower (Carpenter et al., 1995Go) shows CUP expression between the sepal primordia and the centre of the floral meristem. (D) By stage 5, CUP expression can be seen between the emerging primordia in all whorls. (E) In longitudinal sections within whorls, CUP expression can also be observed between organs, in this case between two stamen primordia in a stage 5 flower. (F) At later stages of flower development a strong line of CUP expression is observed in the connective of the anthers. Expression is also observed at the tip of developing carpels in whorl 4. (G) CUP expression is observed between emerging ovule primordia and in the ovule primordia themselves. (H) More mature ovules show CUP expression in a ring surrounding the nucellus at the point of integument attachment. An enlargement of one ovule (inset) shows the ring of CUP expression. Numbers indicate floral whorls. se, sepal; br, bract; pl, placenta; cw, carpel wall; n, nucellus; i, integument. Scale bars: 100 µm.

 


View larger version (65K):

[in a new window]
  		Fig. 5. CUP interacts with TIC. (A) The interaction between CUP and TIC, first detected in a yeast two-hybrid screen, was confirmed by GST pulldown. The lanes labelled CUP and TIC contain in vitro synthesised, radiolabelled CUP and TIC protein controls, respectively. The lanes labelled CUP* and TIC* contain the pulldown products resulting from combining labelled CUP or TIC with GST-fusion proteins with CUP (CUPG) or TIC (TICG) or GST alone. The strong band in the CUP*TICG lane corresponds to an interaction between labelled CUP and GST-TIC. A weaker band in the TIC*CUPG lane shows the interaction between labelled TIC and GST-CUP. A band is also observed in the TIC*TICG lane, indicating that TIC also interacts with itself. (B) The tissue specific expression of TIC and CUP was investigated by RT-PCR (35 cycles) using RNA derived from leaf (L), inflorescence (I), sepal (Se), petal (P), stamen (St) and carpel (C) tissues. The expression pattern of CUP is as expected from in situ hybridisation experiments, being absent from mature leaves, sepals and stamens, and present in carpels and petals. The strongest expression is detected in inflorescences, where in situ hybridisation shows that CUP is expressed at the many boundaries between developing meristems and primordia. The expression pattern of TIC broadly follows that of CUP, but shows a wider tissue distribution. Equal loading is shown by an elongation factor control.

 

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?



© The Company of Biologists Ltd 2004