PMC

The numbers labeled on the right are the cycle numbers of the corresponding genes in the RT-PCR. The primer sequences were from the reference .

A: The primary stem-cauline leaf junction fusion seen in abcb19-5 was enhanced by ett-3. White arrowheads indicate stem-cauline leaf fusion. B: The rate of fusion in abcb19 was obviously enhanced by ett-3. At least 30 samples were analyzed. The values represent the mean and standard deviation from two independent biological replicates (N = 2). */**Significantly different (p<0.05/p<0.01). Scale bar = 2.5 mm in A.

A: abcb19-5 flowers later than wild-type (WT). B and C: Eight-day-old wild-type and abcb19-5 plants. abcb19-5 exhibits epinastic cotyledons and wavy roots. D and E: Four-day-old seedlings grown in the dark. The hypocotyls of abcb19-5 are wave-shaped, while those of WT are straight. F and G: Stem-cauline leaf junctions in WT and abcb19-5. abcb19-5 shows a stem-leaf fusion phenotype. H and I: Stem-pedicel junctions in WT and abcb19-5. The first several pedicels were fused with the main stem in abcb19-5. The arrowheads in G and I indicate the fusion sites. J Pedicel angle of the first 20 siliques in WT and abcb19-5. For each silique position, 10 samples were photographed and the angles were analyzed using Image J. Scale bar = 2.5 mm in C and E, and 5 mm in G and I.

A: Fusion defects between the primary stem and cauline leaf in abcb19-5, abcb19-5 cuc2, abcb19-5 cuc3, and cuc2 cuc3. White arrowheads indicate stem-cauline leaf fusion; white arrow shows the fusion of axillary shoot to the main stem. B: Fusion defects between the primary inflorescence stem and pedicel in abcb19-5, abcb19-5 cuc2, abcb19-5 cuc3, and cuc2 cuc3. White arrowheads indicate stem-pedicel fusion. C: The rate of fusion at primary stem-cauline leaf junctions in different genotypes. At least 30 samples were analyzed for each genotype in every biological replicate. The values represent the mean and standard deviation from two independent biological replicates (N = 2). * Significantly different, P<0.05. Scale bar = 5 mm in A and B.

The upper and lower panels are representative of the DII-VENUS fluorescence signal in wild type and abcb19-5 plants, respectively. Plants were from the F2 population of abcb19-5×DII-VENUS. Among the 19 wild type plants, 16 of them had similar (8) or even stronger (8) signal than the upper panel; only 3 plants show a weak signal than that in the upper panel. However, only 5 among 22 abcb19 plants had similar level of fluorescence to the lower panel; for the other 16 plants, almost no signal was detected in the inflorescence apex; and only one plant show fluorescence signal as strong as that in the upper panel. As a whole, the DII-VENUS signal is obviously reduced in abcb19. Arrowheads indicate the organ boundary between inflorescence meristem and floral primordia. IM, inflorescence meristem. Bar  =  50 µm.

A: The upper model shows the gene structure of ABCB19. The filled black boxes and lines represent exons and introns, respectively. The lower model shows the protein structure of ABCB19. The protein domain information was analyzed at http://smart.embl-heidelberg.de. The gray boxes and ellipses represent the transmembrane domains and ATP-binding domains in ABCB19, respectively. P1, P2, P3 and P4 are primers used in transcript identification. TAIL-PCR revealed that the T-DNA insertion in abcb19-5 was in the last exon and the ATP-binding domain in ABCB19 (shown by triangles). The electrophoretic image shows that abcb19-5 expressed a partial transcript (P3/P4) rather than the full-length transcript (P1/P2). Rosette leaves (B), leaf-stem fusion (C), and stem-pedicel fusion defects (D) in F1 plants of abcb19-5×abcb19-3, abcb19-3 (mdr1-3), and abcb19-5. E-H Transgenic complementation of abcb19-5 by CaMV 35S::ABCB19. E RNA expression level of abcb19-5 in two transgenic recovered plants (Re-1 and -2 are two representative recovered lines). The upper and lower panels represent ABCB19 and ACTIN, respectively. F The rosette leaf shape was complemented by ABCB19. G and H Restoration of the stem-cauline leaf and stem-pedicel fusion defects. Arrowheads indicate the fusion sites. Scale = 10 mm in B and F, and 2 mm in C, D, G, and H.

A: A longitudinal paraffin section after histological GUS staining of the inflorescence meristem region after the floral transition. Compared with WT, the level of CUC2::GUS activity in abcb19-5 was obviously reduced. B: Histological CUC2::GUS staining of the inflorescence, cauline leaves, and axillary branches done after bolting. The CUC2::GUS level was low in abcb19-5. C and D: β-glucuronidase assay of CUC2::GUS in wild type and abcb19-5 stem-cauline leaf junctions and inflorescences. For C and D, the values are the mean and standard deviation from three biological replicates (N = 3). The decrease in CUC2::GUS activity in abcb19-5 was significant (Student's t-test, p = 0.046 in C and p = 0.026 in D). * Significantly different, P<0.05. E and F were similar results as A and B, respectively, except that these are in abcb19-3. G: Relative expression level of CUC2 revealed by real-time quantitative-PCR using about 3 mm region including the stem-cauline leaf junction from the secondary branch. ACTIN2 was used as an endogenous control. Error bars indicate the standard deviation from the three biological replicates. *** Significantly different from the wild type, P<0.001. H: Histological CUC3::GUS staining of the inflorescence, cauline leaves, and axillary branches. The CUC3::GUS level in abcb19-5 was not obviously different from that in WT. I and J: β-glucuronidase assay of CUC3::GUS in wild-type and abcb19-5 stem-cauline leaf junctions and inflorescences. For I and J, the values are the mean and standard deviation from three independent biological replicates (N = 3). CUC3::GUS activity in abcb19-5 was not significantly different from that in WT (Student's t-test, p = 0.152 in I and p = 0.756 in J). m, meristem; p, pedicel; ab, axillary bud; cl, cauline leaf. Bar  =  200 µm in A and E, 1 mm in B and F and 5 mm in H.