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Abstract Anthurium andraeanum is a high-grade potted flower that enjoys global popularity. Its floral organs have been substantially modified, and its ornamental value is based on its petaloid bracts. MADS-box gene products are important transcription factors that control plant development. In particular, the APETALA1 (AP1)/ FRUITFULL (FUL) family of MADS-box genes plays a key role in flowering transitions and out-whorl floral organ identity specification. In this report, one FUL -like gene was cloned from Anthurium andraeanum and named AaFUL1 after bioinformatics identification. Subsequent subcellular localization experiments confirmed that the AaFUL1 protein was located in the nucleus, and data obtained from an expression analysis indicated that the relative expression level of AaFUL1 was the highest in bracts and inflorescences, while its expression was relatively low in stems and roots. Next, an AaFUL1 overexpression vector was constructed and ectopically expressed in tobacco. The transformants did not show any early flowering phenotype, but the average internode length of the inflorescence branch was significantly higher than that observed in the control, and its petal color had substantially faded. The morphology of the petal and pistil was clearly changed, the fruit was deformed, and the seed was largely aborted. These data indicate that even though the sequence of AaFUL1 is relatively conserved, its function differs from that of other orthologs, and the FUL subfamily of MADS-box transcription factors may have taken on new functions during the evolution processes. The results of this experiment enrich our knowledge of FUL transcription factors in monocotyledon plants. Highlights • A new FUL-like gene, AaFUL1 , that encodes 255 amino acid residues was cloned from Anthurium andraeanum. • Subcellular localization experiments showed that the transcription factor located in the nucleus. • Expression pattern analysis indicated that AaFUL1 expressed the highest in spathe, followed by inflorescence. • Overexpression of AaFUL1 in tobacco made the petal color much lighter and seeds largely aborted. [ABSTRACT FROM AUTHOR]

Chloroplasts convert solar energy into biologically useful forms of energy by performing photosynthesis. Although light and particular genes are known to promote chloroplast development, little is known about the mechanisms that regulate the tissue‐specificity and cell‐specificity of chloroplast biogenesis. Thus, the mechanisms that determine whether non‐photosynthetic plastids rather than chloroplasts develop in petals remain largely unexplored. Although heat stress is known to inhibit photosynthesis, we do not know whether heat stress affects chloroplast biogenesis. Here, we report that heat stress up‐regulates the expression of chlorophyll biosynthesis‐related genes and promotes chloroplasts biogenesis in petals overexpressing SOC1 (suppressor of overexpression of CO) and novel SOC1‐like genes. We also found that these specific MADS‐box transcription factors are present in most photosynthetic eukaryotes and that the expression of more than one homolog is observed in chloroplast‐containing tissues. These findings not only provide novel insights into the tissue specificity of chloroplast biogenesis and a method for producing green petals but also are consistent with heat stress influencing chloroplast biogenesis in higher plants. Mechanisms that control the tissue specificity of chloroplast biogenesis are poorly understood. We found that overexpressing genes encoding particular MADS‐box transcription factors up‐regulate the expression of chlorophyll biosynthesis‐related genes and promote chloroplasts biogenesis in the petals of heat‐stressed plants. These findings provide novel insight into the mechanisms that control the tissue specificity of chloroplast biogenesis and a method for producing green petals. [ABSTRACT FROM AUTHOR]

FBP21 is one of the SOC1-like genes isolated from Petunia hybrida. Based on sequence analysis, FPB21 is suggested to have a role in promoting flowering. In this study, FBP21 was expressed in a tobacco host plant under the control of the CaMV 35S promoter. Our results showed that the transgene accelerated flowering, i.e. the transgenic plants flowered just 3 months after germination, in comparison to the wild-type tobacco which flowered after 5 months. Plant morphology was also affected, with the transgenic tobacco plants developing at least five robust lateral branches, while the control plants generally had just three. Total leaf area was significantly reduced in the transgenic tobacco compared to wild-type tobacco. By contrast, there was no significant difference between transgenic and control plants for the total number of flowers or fruits. Thus, the flower or fruit yield expressed per unit leaf area was higher in transgenic tobacco than in wild-type plants. Semi-quantitative RT-PCR analysis indicated that overexpression of FBP21 in tobacco resulted in the up-regulation of some flowering-related genes. The results of this study in tobacco indicate that the Petunia FBP21 gene may permit the engineering of early-flowering and short-growth habits without compromising flower or fruit yields. [ABSTRACT FROM AUTHOR]