Deciphering the evolutionary development of the "Chinese lantern" within Solanaceae.

MAIN CONCLUSION: The key genetic variation underlying the evo-devo of ICS in Solanaceae may be further pinpointed using an integrated strategy of forward and reverse genetics studies under the framework of phylogeny. The calyx of Physalis remains persistent throughout fruit development. Post-flowering, the fruiting calyx is inflated rapidly to encapsulate the berry, giving rise to a "Chinese lantern" structure called inflated calyx syndrome (ICS). It is unclear how this novelty arises. Over the past 2 decades, the role of MADS-box genes in the evolutionary development (evo-devo) of ICS has mainly been investigated within Solanaceae. In this review, we analyze the main achievements, challenges, and new progress. ICS acts as a source for fruit development, provides a microenvironment to protect fruit development, and assists in long-distance fruit dispersal. ICS is a typical post-floral trait, and the onset of its development is triggered by specific developmental signals that coincide with fertilization. These signals can be replaced by exogenous gibberellin and cytokinin application. MPF2-like heterotopic expression and MBP21-like loss have been proposed to be two essential evolutionary events for ICS origin, and manipulating the related MADS-box genes has been shown to affect the ICS size, sepal organ identity, and/or male fertility, but not completely disrupt ICS. Therefore, the core genes or key links in the ICS biosynthesis pathways may have undergone secondary mutations during evolution, or they have not yet been pinpointed. Recently, we have made some encouraging progress in acquiring lantern mutants in Physalis floridana. In addition to technological innovation, we propose an integrated strategy to further analyze the evo-devo mechanisms of ICS in Solanaceae using forward and reverse genetics studies under the framework of phylogeny.

Unraveling the Genetic Control of Pigment Accumulation in Physalis Fruits.

Physalis pubescens and Physalis alkekengi, members of the Physalis genus, are valued for their delicious and medicinal fruits as well as their different ripened fruit colors-golden for P. pubescens and scarlet for P. alkekengi. This study aimed to elucidate the pigment composition and genetic mechanisms during fruit maturation in these species. Fruit samples were collected at four development stages, analyzed using spectrophotometry and high-performance liquid chromatography (HPLC), and complemented with transcriptome sequencing to assess gene expression related to pigment biosynthesis. ß-carotene was identified as the dominant pigment in P. pubescens, contrasting with P. alkekengi, which contained both lycopene and ß-carotene. The carotenoid biosynthesis pathway was central to fruit pigmentation in both species. Key genes pf02G043370 and pf06G178980 in P. pubescens, and TRINITY_DN20150_c1_g3, TRINITY_DN10183_c0_g1, and TRINITY_DN23805_c0_g3 in P. alkekengi were associated with carotenoid production. Notably, the MYB-related and bHLH transcription factors (TFs) regulated zeta-carotene isomerase and ß-hydroxylase activities in P. pubescens with the MYB-related TF showing dual regulatory roles. In P. alkekengi, six TF families-bHLH, HSF, WRKY, M-type MADS, AP2, and NAC-were implicated in controlling carotenoid synthesis enzymes. Our findings highlight the intricate regulatory network governing pigmentation and provide insights into Physalis germplasm's genetic improvement and conservation.

Production and Structural Diversification of Withanolides by Aeroponic Cultivation of Plants of Solanaceae: Cytotoxic and Other Withanolides from Aeroponically Grown Physalis coztomatl.

Withanolides constitute one of the most interesting classes of natural products due to their diversity of structures and biological activities. Our recent studies on withanolides obtained from plants of Solanaceae including Withania somnifera and a number of Physalis species grown under environmentally controlled aeroponic conditions suggested that this technique is a convenient, reproducible, and superior method for their production and structural diversification. Investigation of aeroponically grown Physalis coztomatl afforded 29 withanolides compared to a total of 13 obtained previously from the wild-crafted plant and included 12 new withanolides, physacoztolides I-M (9-13), 15α-acetoxy-28-hydroxyphysachenolide C (14), 28-oxophysachenolide C (15), and 28-hydroxyphysachenolide C (16), 5α-chloro-6ß-hydroxy-5,6-dihydrophysachenolide D (17), 15α-acetoxy-5α-chloro-6ß-hydroxy-5,6-dihydrophysachenolide D (18), 28-hydroxy-5α-chloro-6ß-hydroxy-5,6-dihydrophysachenolide D (19), physachenolide A-5-methyl ether (20), and 17 known withanolides 3-5, 8, and 21-33. The structures of 9-20 were elucidated by the analysis of their spectroscopic data and the known withanolides 3-5, 8, and 21-33 were identified by comparison of their spectroscopic data with those reported. Evaluation against a panel of prostate cancer (LNCaP, VCaP, DU-145, and PC-3) and renal carcinoma (ACHN) cell lines, and normal human foreskin fibroblast (WI-38) cells revealed that 8, 13, 15, and 17-19 had potent and selective activity for prostate cancer cell lines. Facile conversion of the 5,6-chlorohydrin 17 to its 5,6-epoxide 8 in cell culture medium used for the bioassay suggested that the cytotoxic activities observed for 17-19 may be due to in situ formation of their corresponding 5ß,6ß-epoxides, 8, 27, and 28.

Effect of Salt Stress on Growth and Metabolite Profiles of Cape Gooseberry (Physalis peruviana L.) along Three Growth Stages.

Colombia is the main producer of cape gooseberry (Physalis peruviana L.), a plant known for its various consumption practices and medicinal properties. This plant is generally grown in eroded soils and is considered moderately tolerant to unfavorable conditions, such as nutrient-poor soils or high salt concentrations. Most studies conducted on this plant focus on fruit production and composition because it is the target product, but a small number of studies have been conducted to describe the effect of abiotic stress, e.g., salt stress, on growth and biochemical responses. In order to better understand the mechanism of inherent tolerance of this plant facing salt stress, the present study was conducted to determine the metabolic and growth differences of P. peruviana plants at three different BBCH-based growth substages, varying salt conditions. Hence, plants were independently treated with two NaCl solutions, and growth parameters and LC-ESI-MS-derived semi-quantitative levels of metabolites were then measured and compared between salt treatments per growth substage. A 90 mM NaCl treatment caused the greatest effect on plants, provoking low growth and particular metabolite variations. The treatment discrimination-driving feature classification suggested that glycosylated flavonols increased under 30 mM NaCl at 209 substages, withanolides decreased under 90 mM NaCl at 603 and 703 substages, and up-regulation of a free flavonol at all selected stages can be considered a salt stress response. Findings locate such response into a metabolic context and afford some insights into the plant response associated with antioxidant compound up-regulation.

Carotenogenesis and chromoplast development during ripening of yellow, orange and red colored Physalis fruit.

MAIN CONCLUSION: Formation of specific ultrastructural chromoplastidal elements during ripening of fruits of three different colored Physalis spp. is closely related to their distinct carotenoid profiles. The accumulation of color-determining carotenoids within the chromoplasts of ripening yellow, orange, and red fruit of Physalis pubescens L., Physalis peruviana L., and Physalis alkekengi L., respectively, was monitored by high-performance liquid chromatography/diode array detector/tandem mass spectrometry (HPLC-DAD-MS/MS) as well as light and transmission electron microscopy. Both yellow and orange fruit gradually accumulated mainly ß-carotene and lutein esters at variable levels, explaining their different colors at full ripeness. Upon commencing ß-carotene biosynthesis, large crystals appeared in their chromoplasts, while large filaments protruding from plastoglobules were characteristic elements of chromoplasts of orange fruit. In contrast to yellow and orange fruit, fully ripe red fruit contained almost no ß-carotene, but esters of both ß-cryptoxanthin and zeaxanthin at very high levels. Tubule bundles and unusual disc-like crystallites were predominant carotenoid-bearing elements in red fruit. Our study supports the earlier hypothesis that the predominant carotenoid type might shape the ultrastructural carotenoid deposition form, which is considered important for color, stability and bioavailability of the contained carotenoids.

Transcriptomic variation of the flower-fruit transition in Physalis and Solanum.

MAIN CONCLUSION: Gene expression variations in response to fertilization between Physalis and Solanum might play essential roles in species divergence and fruit evolution. Fertilization triggers variation in fruit development and morphology. The Chinese lantern, a morphological novelty derived from the calyx, is formed upon fertilization in Physalis but is not observed in Solanum. The underlying genetic variations are largely unknown. Here, we documented the developmental and morphological differences in the flower and fruit between Physalis floridana and Solanum pimpinellifolium and then evaluated both the transcript sequence variation and gene expression at the transcriptomic level at fertilization between the two species. In Physalis transcriptomic analysis, 468 unigenes were identified as differentially expressed genes (DEGs) that were strongly regulated by fertilization across 3 years. In comparison with tomato, 14,536 strict single-copy orthologous gene pairs were identified between P. floridana and S. pimpinellifolium in the flower-fruit transcriptome. Nine types of gene variations with specific GO-enriched patterns were identified, covering 58.82% orthologous gene pairs that were DEGs in either trend or dosage at the flower-fruit transition between the two species, which could adequately distinguish Solanum and Physalis, implying that differential gene expression at fertilization might play essential roles during the divergence and fruit evolution of Solanum-Physalis. Virus-induced gene silencing analyses revealed the developmental roles of some transcription factor genes in fertility, Chinese lantern development, and fruit weight control in Physalis. This study presents the first floral transcriptomic resource of Physalis, and reveals some candidate genetic variations accounting for the early fruit developmental evolution in Physalis in comparison to Solanum.

Exon junction complex (EJC) core genes play multiple developmental roles in Physalis floridana.

KEY MESSAGE: Molecular and functional characterization of four gene families of the Physalis exon junction complex (EJC) core improved our understanding of the evolution and function of EJC core genes in plants. The exon junction complex (EJC) plays significant roles in posttranscriptional regulation of genes in eukaryotes. However, its developmental roles in plants are poorly known. We characterized four EJC core genes from Physalis floridana that were named PFMAGO, PFY14, PFeIF4AIII and PFBTZ. They shared a similar phylogenetic topology and were expressed in all examined organs. PFMAGO, PFY14 and PFeIF4AIII were localized in both the nucleus and cytoplasm while PFBTZ was mainly localized in the cytoplasm. No protein homodimerization was observed, but they could form heterodimers excluding the PFY14-PFBTZ heterodimerization. Virus-induced gene silencing (VIGS) of PFMAGO or PFY14 aborted pollen development and resulted in low plant survival due to a leaf-blight-like phenotype in the shoot apex. Carpel functionality was also impaired in the PFY14 knockdowns, whereas pollen maturation was uniquely affected in PFBTZ-VIGS plants. Once PFeIF4AIII was strongly downregulated, plant survival was reduced via a decomposing root collar after flowering and Chinese lantern morphology was distorted. The expression of Physalis orthologous genes in the DYT1-TDF1-AMS-bHLH91 regulatory cascade that is associated with pollen maturation was significantly downregulated in PFMAGO-, PFY14- and PFBTZ-VIGS flowers. Intron-retention in the transcripts of P. floridana dysfunctional tapetum1 (PFDYT1) occurred in these mutated flowers. Additionally, the expression level of WRKY genes in defense-related pathways in the shoot apex of PFMAGO- or PFY14-VIGS plants and in the root collar of PFeIF4AIII-VIGS plants was significantly downregulated. Taken together, the Physalis EJC core genes play multiple roles including a conserved role in male fertility and newly discovered roles in Chinese lantern development, carpel functionality and defense-related processes. These data increase our understanding of the evolution and functions of EJC core genes in plants.

Withanolides from Aeroponically Grown Physalis peruviana and Their Selective Cytotoxicity to Prostate Cancer and Renal Carcinoma Cells.

Investigation of aeroponically grown Physalis peruviana resulted in the isolation of 11 new withanolides, including perulactones I-L (1-4), 17-deoxy-23ß-hydroxywithanolide E (5), 23ß-hydroxywithanolide E (6), 4-deoxyphyperunolide A (7), 7ß-hydroxywithanolide F (8), 7ß-hydroxy-17-epi-withanolide K (9), 24,25-dihydro-23ß,28-dihydroxywithanolide G (10), and 24,25-dihydrowithanolide E (11), together with 14 known withanolides (12-25). The structures of 1-11 were elucidated by the analysis of their spectroscopic data, and 12-25 were identified by comparison of their spectroscopic data with those reported. All withanolides were evaluated for their cytotoxic activity against a panel of tumor cell lines including LNCaP (androgen-sensitive human prostate adenocarcinoma), 22Rv1 (androgen-resistant human prostate adenocarcinoma), ACHN (human renal adenocarcinoma), M14 (human melanoma), SK-MEL-28 (human melanoma), and normal human foreskin fibroblast cells. Of these, the 17ß-hydroxywithanolides (17-BHWs) 6, 8, 9, 11-13, 15, and 19-22 showed selective cytotoxic activity against the two prostate cancer cell lines LNCaP and 22Rv1, whereas 13 and 20 exhibited selective toxicity for the ACHN renal carcinoma cell line. These cytotoxicity data provide additional structure-activity relationship information for the 17-BHWs.

The euAP1 protein MPF3 represses MPF2 to specify floral calyx identity and displays crucial roles in Chinese lantern development in Physalis.

The Chinese lantern phenotype or inflated calyx syndrome (ICS) is a postfloral morphological novelty in Physalis. Its origin is associated with the heterotopic expression of the MADS box gene 2 from Physalis floridana (MPF2) in floral organs, yet the process underlying its identity remains elusive. Here, we show that MPF3, which is expressed specifically in floral tissues, encodes a core eudicot APETALA1-like (euAP1) MADS-domain protein. MPF3 was primarily localized to the nucleus, and it interacted with MPF2 and some floral MADS-domain proteins to selectively bind the CC-A-rich-GG (CArG) boxes in the MPF2 promoter. Downregulating MPF3 resulted in a dramatic elevation in MPF2 in the calyces and androecium, leading to enlarged and leaf-like floral calyces; however, the postfloral lantern was smaller and deformed. Starch accumulation in pollen was blocked. MPF3 MPF2 double knockdowns showed normal floral calyces and more mature pollen than those found in plants in which either MPF3 or MPF2 was downregulated. Therefore, MPF3 specifies calyx identity and regulates ICS formation and male fertility through interactions with MPF2/MPF2. Furthermore, both genes were found to activate Physalis floridana invertase gene 4 homolog, which encodes an invertase cleaving Suc, a putative key gene in sugar partitioning. The novel role of the MPF3-MPF2 regulatory circuit in male fertility is integral to the origin of ICS. Our results shed light on the evolution and development of ICS in Physalis and on the functional evolution of euAP1s in angiosperms.

17ß-Hydroxy-18-acetoxywithanolides from Aeroponically Grown Physalis crassifolia and Their Potent and Selective Cytotoxicity for Prostate Cancer Cells.

When cultivated under aeroponic growth conditions, Physalis crassifolia produced 11 new withanolides (1-11) and seven known withanolides (12-18) including those obtained from the wild-crafted plant. The structures of the new withanolides were elucidated by the application of spectroscopic techniques, and the known withanolides were identified by comparison of their spectroscopic data with those reported. Withanolides 1-11 and 16 were evaluated for their potential anticancer activity using five tumor cell lines. Of these, the 17ß-hydroxy-18-acetoxywithanolides 1, 2, 6, 7, and 16 showed potent antiproliferative activity, with some having selectivity for prostate adenocarcinoma (LNCaP and PC-3M) compared to the breast adenocarcinoma (MCF-7), non-small-cell lung cancer (NCI-H460), and CNS glioma (SF-268) cell lines used. The cytotoxicity data obtained for 12-15, 17, and 19 have provided additional structure-activity relationship information for the 17ß-hydroxy-18-acetoxywithanolides.

Effect of osmopriming on germination and initial growth of Physalis angulata L. under salt stress and on expression of associated genes.

This study aimed to evaluate the effects of priming on seed germination under salt stress and gene expression in seeds and seedlings of P. angulata L. After priming for 10 days, seed germination was tested in plastic trays containing 15 ml of water (0 dS m-1 - control) or 15 ml of NaCl solution (2, 4, 6, 8, 10, 12, 14 and 16 dS m-1). Fresh and dry weight of shoots and roots of seedlings were evaluated at 0, 2, 4, 6, 8 dS m-1. Total RNA was extracted from whole seeds and seedlings followed by RT-qPCR. The target genes selected for this study were: ascorbate peroxidase (APX), glutathione-S-transferase (GST), thioredoxin (TXN), high affinity potassium transporter protein 1 (HAK1) and salt overly sensitive 1 (SOS1). At an electroconductivity of 14 dS m-1 the primed seeds still germinated to 72%, in contrast with the non-primed seeds which did not germinate. The relative expression of APX was higher in primed seeds and this may have contributed to the maintenance of high germination in primed seeds at high salt concentrations. GST and TXN displayed increased transcript levels in shoots and roots of seedlings from primed seeds. Priming improved seed germination as well as salt tolerance and this is correlated with increased expression of APX in seeds and SOS1, GST and TXN in seedlings.

Evaluation of antidesmone alkaloid as a photosynthesis inhibitor.

Antidesmone, isolated from Waltheria brachypetala Turcz., owns special structural features as two α,ß-unsaturated carbonyl groups and a side alkyl chain that can compete with the quinones involved in the pool of plastoquinones at photosystem II (PSII). In this work, we showed that the alkaloid is an inhibitor of Hill reaction and its target was located at the acceptor side of PSII. Studies of chlorophyll (Chl) a fluorescence showed a J-band that indicates direct action of antidesmone in accumulation of QA- (reduced plastoquinone A) due to the electron transport blocked at the QB (plastoquinone B) level similar to DCMU. In vivo assays indicated that antidesmone is a selective post-emergent herbicide probe at 300µM by reducing the biomass production of Physalis ixacarpa plants. Furthermore, antidesmone also behaves as pre-emergent herbicide due to inhibit Physalis ixacarpa plant growth about 60%. Antidesmone, a natural product containing a 4(1H)-pyridones scaffold, will serve as a valuable tool in further development of a new class of herbicides.

Deciphering the Physalis floridana double-layered-lantern1 mutant provides insights into functional divergence of the GLOBOSA duplicates within the Solanaceae.

Physalis spp. develop the "Chinese lantern" trait, also known as inflated calyx syndrome, that is a morphological novelty. Here, we identified the double-layered-lantern1 (doll1) mutant, a recessive and monofactorial mutation, in Physalis floridana; its corolla and androecium were transformed into the calyx and gynoecium, respectively. Two GLOBOSA-like MADS-box paralogous genes PFGLO1 and PFGLO2 were found in Physalis floridana, while the mutated phenotype was cosegregated with a large deletion harboring PFGLO1 and was complemented by the PFGLO1 genomic locus in transgenic plants, and severe PFGLO1 knockdowns phenocopied doll1. Thus, DOLL1 encodes the PFGLO1 protein and plays a primary role in determining corolla and androecium identity. However, specific PFGLO2 silencing showed no homeotic variation but rather affected pollen maturation. The two genes featured identical floral expression domains, but the encoding proteins shared 67% identity in sequences. PFGLO1 was localized in the nucleus when expressed in combination with a DEFICIENS homolog from Physalis floridana, whereas PFGLO2 was imported to the nucleus on its own. The two proteins were further found to have evolved different interacting partners and regulatory patterns, supporting the hypothesis that PFGLO2 is functionally separated from organ identity. Such a divergent pattern of duplicated GLO genes is unusual within the Solanaceae. Moreover, the phenotypes of the PFGLO1PFGLO2 double silencing mutants suggested that PFGLO2, through genetically interacting with PFGLO1, also exerts a role in the control of organ number and tip development of the second floral whorl. Our results, therefore, shed new light on the functional evolution of the duplicated GLO genes.

Physalis floridana Cell Number Regulator1 encodes a cell membrane-anchored modulator of cell cycle and negatively controls fruit size.

Physalis species show a significant variation in berry size; however, the underlying molecular basis is unknown. In this work, we showed that cell division difference in the ovaries might contribute to the ultimate berry size variation within Physalis species, and that mRNA abundance of Physalis floridana Cell Number Regulator1 (PfCNR1), the putative orthologue of the tomato fruit weight 2.2 (FW2.2), was negatively correlated with cell division in the ovaries. Moreover, heterochronic expression variation of the PfCNR1 genes in the ovaries concomitantly correlated with berry weight variation within Physalis species. In transgenic Physalis, multiple organ sizes could be negatively controlled by altering PfCNR1 levels, and cell division instead of cell expansion was primarily affected. PfCNR1 was shown to be anchored in the plasma membrane and to interact with PfAG2 (an AGAMOUS-like protein determining ovary identity). The expression of PfCYCD2;1, a putative orthologue of the mitosis-specific gene CyclinD2;1 in the cell cycle was negatively correlated with the PfCNR1 mRNA levels. PfAG2 was found to selectively bind to the CArG-box in the PfCYCD2;1 promoter and to repress PfCYCD2;1 expression, thus suggesting a PfAG2-mediated pathway for PfCNR1 to regulate cell division. The interaction of PfCNR1 with PfAG2 enhanced the repression of PfCYCD2;1 expression. The nuclear import of PfAG2 was essential in the proposed pathway. Our data provide new insights into the developmental pathways of a cell membrane-anchored protein that modulates cell division and governs organ size determination. This study also sheds light on the link between organ identity and organ growth in plants.

Influence of cultivar and ripening time on bioactive compounds and antioxidant properties in Cape gooseberry (Physalis peruviana L.).

BACKGROUND: Cape gooseberry (Physalis peruviana) is an exotic fruit highly valued for its organoleptic properties and bioactive compounds. Considering that the presence of phenolics and ascorbic acid could contribute to its functional capacity, it is important to investigate the quality parameters, bioactive contents and functional properties with respect to genotype and ripening time. In this study the genotype effect was evaluated in 15 cultivars for two different harvest times. Changes during maturation were recorded in two commercial cultivars within seven levels of maturity. RESULTS: Multivariate statistical analysis suggested that phenolic content and ORAC value were mainly affected by harvest time and that ascorbic acid content and DPPH level were mainly affected by genotype. In addition, acidity, phenolic content, ORAC value and inhibition of LDL oxidation decreased with maturity, but soluble solids content, ascorbic acid content, ß-carotene content and DPPH-scavenging activity were higher in mature fruits. CONCLUSION: The phenolic content, ascorbic acid content and antioxidant properties of Cape gooseberry fruit were strongly affected by cultivar, harvest time and maturity state. Consequently, the harvest time must be scheduled carefully to gain the highest proportion of bioactive compounds according to the specific cultivar and the environment where it is grown.

Transcriptome-wide mining of the differentially expressed transcripts for natural variation of floral organ size in Physalis philadelphica.

Natural phenotypic variation, a result of genetic variation, developed during evolution in response to environmental selections. Physalis philadelphica, known as tomatillo in the Solanaceae, is rich in floral and post-floral organ size diversity. However, its genetic variation is unknown. Here P. philadelphica was classified into three groups with large, intermediate, and small reproductive organ size, and a positive correlation was observed between floral organ and berry sizes. Through cDNA-amplified fragment length polymorphism (AFLP) analyses, 263 differentially expressed transcript-derived fragments (TDFs) were isolated from two accessions with different floral organ sizes. The genes encode various transcription factors, protein kinases, and enzymes, and they displayed multiple expression patterns during floral development, indicating a complexity in the genetic basis of phenotypic variation. Detailed expression analyses revealed that they were differentially expressed during floral and post-floral development, implying that they have roles in the development of flowers and fruits. Expression of three genes was further monitored in 26 accessions, and in particular the expression variation of Pp30, encoding an AP2-like transcription factor, correlates well with the observed phenotypic variations, which strongly supports an essential role for the gene in the natural variation of floral and post-floral organ size in Physalis. The results suggest that alteration in the expression pattern of a few key regulatory genes in the developmental process may be an important source of genetic variations that lead to natural variation in morphological traits.

Anther Culture of the Gametophytic Self-Incompatible Species Physalis ixocarpa Brot.

Here we present an optimized protocol for in vitro embryo formation and plant regeneration through anther culture of the Mexican husk tomato (Physalis ixocarpa Brot.). This protocol relies on the application of an anther thermal shock at a specific developmental stage prior to the in vitro culture, ensures embryo formation from anthers without callus formation, and allows spending less time to regenerate doubled haploid complete plants. This protocol has been used for different cultivars of Physalis ixocarpa (Chapingo, Rendidora, Puebla, Arandaz, Manzano, Tamazula, Salamanca, and Milpero), and also for two wild-type accessions, all of them cultivated in Mexico. Chapingo cultivar responded with the highest percentage of androgenesis on the embryo induction medium (EIM).

The MADS-domain protein MPF1 of Physalis floridana controls plant architecture, seed development and flowering time.

Floral and vegetative development of plants is dependent on the combinatorial action of MADS-domain transcription factors. Members of the STMADS11 subclade, such as MPF1 of Physalis, are abundantly expressed in leaves as well as in floral organs, but their function is not yet clear. Our studies with transgenic Arabidopsis that over-express MPF1 suggest that MPF1 interacts with SOC1 to determine flowering time. However, MPF1 RNAi-mediated knockdown Physalis plants revealed a complex phenotype with changes in flowering time, plant architecture and seed size. Flowering of these plants was delayed by about 20% as compared to wild type. Expression of PFLFY is upregulated in the MPF1 RNAi lines, while PFFT and MPF3 genes are strongly repressed. MPF1 interacts with a subset of MADS-domain factors, namely with PFSOC1 in planta, and with PFSEP3 and PFFUL in yeast, supporting a regulatory role for this protein in flowering. The average size of seeds produced by the transgenic MPF1 RNAi plants is increased almost twofold. The height of these plants is also increased about twofold, but most axillary buds are stunted when compared to controls. Taken together, this suggests that members of the STMADS11 subclade act as positive regulators of flowering but have diverse functions in plant growth.

Chinese lantern in Physalis is an advantageous morphological novelty and improves plant fitness.

The origin of morphological novelties is an important but neglected issue of evolutionary biology. The fruit of the genus Physalis, a berry, is encapsulated by a novel morphological feature of the post-floral, accrescent calyx that is referred to as a Chinese lantern. The evolutionary developmental genetics of the Chinese lantern have been investigated in the last decade; however, the selective values of the morphological novelty remain elusive. Here, we measured the photosynthetic parameters of the fruiting calyces, monitored microclimatic variation within the Chinese lanterns during fruit development, performed floral-calyx-removal experiments, and recorded the fitness-related traits in Physalis floridana. Ultimately, we show that the green-fruiting calyx of Physalis has photosynthetic capabilities, thus serving as an energy source for fruit development. Moreover, the developing Chinese lantern provides a microclimate that benefits the development and maturation of berry and seed, and it improves plant fitness in terms of fruit/seed weight and number, and fruit maturation under low-temperature environments. Furthermore, the lantern structure facilitates the dispersal of fruits and seeds by water and wind. Our results suggest that the Chinese lantern morphology of Physalis is an evolutionary adaptive trait and improves plant fitness, thus providing new insight into the origin of morphological novelties.

Metabolomic Profiling of Carotenoid Constituents in Physalis peruviana During Different Growth Stages by LC-MS/MS Technology.

With the current ongoing changes in global food demands, natural carotenoids are preferred by consumers and are gaining attention among food scientists and producers alike. Metabolomic profiling of carotenoid constituents in Physalis peruviana during distinct on-tree growth stages was performed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology. The results show that the ß rings of ß-carotene are hydroxylated with great efficiency, and there is a continual synthesis of zeaxanthin at half-ripe and full-ripe stages, which is confirmed by relating the zeaxanthin content to that of its precursor (ß-carotene). Lutein was, in terms of mass intensity, the most abundant carotenoid constituent (64.61 µg/g at the half-ripe stage) observed in this study. In addition, γ-carotene, which is rare in dietary fruits and vegetables, was detected in the mature and breaker stages, albeit at a relatively low level. The results suggest that when we consider the variation in carotenoid content during different growth stages, Physalis peruviana can be considered a good source of natural carotenoids.