Article Figures & Data
Figures
- Figure 1.
Terpenoid Indole Alkaloid Biosynthetic Pathway in C. roseus.
TDC converts tryptophan to tryptamine, and several enzymes convert geraniol into secologanin. STR1 converts tryptamine and secologanin into the central intermediate strictosidine, from which are derived the Iboga, Corynanthe, and Aspidosperma alkaloids, such as ajmalicine, catharanthine, and vindoline, respectively. The condensation of vindoline and catharanthine leads to the biosynthesis of the bisindole alkaloid vinblastine. Single and multiple enzymatic steps are shown as solid and dashed arrows, respectively.
- Figure 2.
Localization of tdc, str1, d4h, and dat mRNA in Developing Leaves.
Paraffin-embedded serial longitudinal sections from 15-mm leaves were hybridized with digoxigenin-labeled transcripts. Hybridized transcripts were immunolocalized with anti-digoxigenin–alkaline phosphatase conjugate followed by BCIP/nitro blue tetrazolium color development. Boxes in the profile of a longitudinal section at the top show the photographed area: the revoluted leaf base (first box; [A], [E], [I], and [M]), the middle area of the leaf at a distance of 4.5 mm from the base (second box; [C], [G], [K], and [O]), and the tip portion of the leaf at 8.5 mm from the base (third box; [D], [H], [L], and [P]). Boxed areas in (A), (E), (I), and (M) are magnified in (B), (F), (J), and (N), respectively. A magnification of the leaf base also is shown in (Q) to (T).
(A) to (D) Sections were hybridized with antisense RNA for tdc.
(E) to (H) Sections were hybridized with antisense RNA for str1.
(I) to (L) Sections were hybridized with antisense RNA for d4h.
(M) to (P) Sections were hybridized with antisense RNA for dat.
(Q) to (T) Sections were hybridized with sense RNA for tdc (Q), str1 (R), d4h (S), and dat (T).
cl, cross-connecting laticifer cells; le, lower epidermis; pm, palisade mesophyll cells; sm, spongy mesophyll cells; t, tracheid; ue, upper epidermis. Solid arrowheads show laticifer cells; open arrowheads point to idioblast cells. Bar in (A) = 100 μm for panels (A), (E), (I), and (M); bar in (C) = 50 μm for (B) to (D), (F) to (H), (J) to (L), and (N) to (T).
- Figure 3.
Localization of dat mRNA, Fluorescent Compounds, and Vascular Tissue in Developing Leaves.
(A) to (D) Paraffin-embedded sections were hybridized with antisense RNA for dat. (A) shows a longitudinal section of the leaf base, (B) a paradermal section mainly through the palisadic mesophyll, (C) a paradermal section 20 μm under the section shown in (B), and (D) magnification of the boxed area shown in (C).
(E) to (H) Reflected light fluorescence microscopy ([E], [F], and [H]) of fresh tissues and cross-illumination microscopy of cleared tissues (G). Shown are fresh hand-cut cross-sections (E), adaxial and abaxial face of whole mount ([F] and [H], respectively), and vascular tissue of the leaf section (G) shown in (F) after clearing of the tissues. cl, cross-connecting laticifer cells; h, trichome; le, lower epidermis; pi, palisade mesophyll–associated idioblast cells; si, spongy mesophyll–associated idioblast cells; t, tracheid; ue, upper epidermis; vl, vasculature-associated laticifer cells. Bars in (A) and (D) = 50 μm; bars in (B), (C), and (E) to (H) = 100 μm.
- Figure 4.
Immunolocalization of TDC, D4H, and DAT Proteins in Developing Leaves.
Longitudinal sections of the same leaf shown in Figure 2. Microscopy is from the base ([A], [C], [E], and [G]) and from the middle portion (4.5 mm from the base) of the leaf ([B], [D], [F], and [H]).
(A) and (B) Leaf section reacted with the TDC antiserum (1:1000).
(C) and (D) Leaf section reacted with the D4H antiserum (1:2500).
(E) and (F) Leaf section reacted with the DAT antiserum (1:400).
(G) and (H) Leaf section reacted with the preimmune antiserum (1:500).
Abbreviations are the same as given for Figure 3. Bars in (A) to (H) = 50 μm.
- Figure 5.
Distribution of Protein and mRNA for Alkaloid Biosynthetic Genes in Dissected Developing Leaves.
Whole leaves (W) and leaves that were dissected into base (B), middle (M), and tip (T) regions, as shown at lower right, were analyzed for antigen levels (right) of TDC, D4H, and DATand RNA levels (left) of tdc, str1, d4h, and dat. Bar = 5 mm.
- Figure 6.
Localization of tdc, str1, d4h, and dat mRNA in Flower Primordia, Stems, and Roots.
Serial longitudinal sections of flower buds ([A], [D], [G], and [J]) and root apices ([C], [F], [I], and [L]) and cross-sections of first internodes under the youngest developing leaf ([B], [E], [H], and [K]) were hybridized with digoxigenin-labeled transcripts.
(A) to (C) Sections were hybridized with antisense RNA for tdc.
(D) to (F) Sections were hybridized with antisense RNA for str1.
(G) to (I) Sections were hybridized with antisense RNA for d4h.
(J) to (L) Sections were hybridized with antisense RNA for dat.
e, epidermal cells; la, laticifer cells; pt, petals; sp, sepals. Arrowheads point to laticifer cells in stem. Bars in (A) to (L) = 100 μm.
