Figure 1.
Rafflesia cantleyi Solms-Laubach buds and flower.
(A) Bud of approximately 4 cm developing on a Tetrastigma sp. vine in the forest in Pulau Tioman, Malaysia. (B) A longitudinal section of an older bud approximately 8 cm in diameter. (C) An open flower of Rafflesia sp. (approximately 1 m in diameter). Scale bars A = 2 cm, B = 1 cm and C = 15 cm.
Figure 2.
Phylogenetic tree of selected MADS-box genes from StMADS11 clade.
(A) The tree was constructed based on the deduced amino acid sequences using the Phylogeny.fr with one click mode. (B) Phylogenetic tree of RcMADS1 with only AGL24, SVP and StMADS11. In both the trees RcMADS1 is nested closer to AGL24 than to SVP. AGL24 and SVP from Arabidopsis thaliana; BnAGL24 from Brassica napus; BjSVP from Brassica juncea; INCOMPOSITA from Antirrhinum majus; IbMADS3 and IbMADS4 from Ipomoea batatas; JOINTLESS from Solanum lycopersicum; MPF2 from Physalis pubescens; MPP3 from Physalis peruviana; OsMADS22, OsMADS47, OsMADS55 from Oryza sativa; PtMADS1 from Populus tomentosa; RcMADS1 from Rafflesia cantleyi; StMADS16 and StMADS11 from Solanum tuberosum; TaVRT2 from Triticum aestivum; ZmMADS22 and ZmMADS26 from Zea mays. The numbers next to the nodes are bootstrap percentages. The scale bars denote a divergence of 0.2 amino acid substitutions per site.
Figure 3.
Ectopic expression of RcMADS1 in Arabidopsis thaliana causes conversion of carpels into inflorescence-like structures.
The stronger phenotypic lines are shown (A) Comparison of 35S::RcMADS1 (right) with WT (left). (B) Close-up of one inflorescence stem of 35S::RcMADS1 (right) and WT (left). (C). A wild-type Arabidopsis flower. (D) A 35S::RcMADS1 flower showing conversion of sepals and petals into leaf-like structures bearing conspicuous trichomes. (E) A 35S::RcMADS1 flower showing the conversion of carpel into an inflorescence-like structure. (F) A 35S::RcMADS1 flower with a secondary inflorescence developing from the axil of a sepal (red arrowhead). (G) 35S::RcMADS1 flowers displaying the three different severities of phenotypes. Weak: flower from EL4 similar to wild-type (left), Medium: flower from EL2 exhibiting conversion of sepals and petals into leaf-like structures while the carpel develops into a silique (middle), Strong: flower from EL8 exhibiting conversion of sepals and petals into leaf-like structures and the carpel is converted into inflorescence-like structure with secondary inflorescences (right). (H) Expression levels of RcMADS1 in the three different transgenic lines exhibiting weak, medium and strong phenotypes. Expression levels were normalized against the expression of TUB2. Error bars indicate s.d. (I) Flowers of 35S::AGL24 (right), 35S::RcMADS1 (middle) and 35S::SVP (left). Scale bars A, B = 1cm, C, D, E, F = 1 mm, G and I = 2 mm.
Figure 4.
Ectopic expression of RcMADS1 causes early flowering in Arabidopsis.
(A) Representative plants from independent transgenic lines showing different flowering times (plant1 WT, plant2 EL4, plant3 EL2 and plant4 EL8). (B) The flowering time of plants in (A) indicated by rosette leaf numbers at bolting. Data are mean ± s.d. from 20 plants of each line. (C) Flowering time comparison of EL8 with WT, 35S::AGL24 and 35S::SVP. Data are mean ± s.d. from 20 plants of each genotype. Asterisks indicate significantly different means (P≤0.05) according to Student’s t-Test. Scale bar = 1cm.
Figure 5.
Complementation analysis of agl24-1 mutant by RcMADS1 expression driven by two different promoters.
(A) Functional complementation of agl24-1 by 35S::RcMADS1. WT (left), agl24-1 mutant (middle) and agl24-1+35S::RcMADS1 (right). (B) The flowering time of plants in (A) represented by rosette leaf numbers at bolting (mean ± s.d.). (C) Functional complementation of agl24-1 by AGL24::RcMADS1. WT (left), agl24-1 mutant (middle) and agl24-1+ AGL24::RcMADS1 (right). (D) The flowering time of plants in (C) represented by rosette leaf numbers at bolting (mean ± s.d.). Asterisks indicate that means are significantly different (P≤0.05) according to Student’s t-Test. Scale bars = 1cm.
Figure 6.
Complementation analysis of svp-41 mutant and rescue of FRI phenotype by RcMADS1 expression.
(A) RcMADS1 failed to rescue svp-41. WT (left), svp-41 mutant (middle) and svp-41+RcMADS1 (right). (B) The flowering time of plants in (A) represented by rosette leaf numbers at bolting (mean ± s.d.). (C) Rescuing of FRI phenotype. WT (left), FRI containing Col line (middle) and FRI containing Col line +RcMADS1 (right). (D) The flowering time of plants in (C) represented by rosette leaf numbers (mean ± s.d.). Asterisks indicate that means are significantly different (P≤0.05) according to Student’s t-Test. Scale bars = 1cm.
Figure 7.
SOC1 expression is up regulated by RcMADS1 during floral transition.
The expression levels of SOC1 in different genotypes (mean ± s.d.) during floral transition. Results were normalized against the expression of TUB2.