The Phalaenopsis orchid produces complex flowers that are commercially valuable, which has promoted the study of its flower development. E‐class MADS‐box genes, SEPALLATA (SEP), combined with B‐, C‐ ...and D‐class MADS‐box genes, are involved in various aspects of plant development, such as floral meristem determination, organ identity, fruit maturation, seed formation and plant architecture. Four SEP‐like genes were cloned from Phalaenopsis orchid, and the duplicated PeSEPs were grouped into PeSEP1/3 and PeSEP2/4. All PeSEPs were expressed in all floral organs. PeSEP2 expression was detectable in vegetative tissues. The study of protein–protein interactions suggested that PeSEPs may form higher order complexes with the B‐, C‐, D‐class and AGAMOUS LIKE6‐related MADS‐box proteins to determine floral organ identity. The tepal became a leaf‐like organ when PeSEP3 was silenced by virus‐induced silencing, with alterations in epidermis identity and contents of anthocyanin and chlorophyll. Silencing of PeSEP2 had minor effects on the floral phenotype. Silencing of the E‐class genes PeSEP2 and PeSEP3 resulted in the downregulation of B‐class PeMADS2‐6 genes, which indicates an association of PeSEP functions and B‐class gene expression. These findings reveal the important roles of PeSEP in Phalaenopsis floral organ formation throughout the developmental process by the formation of various multiple protein complexes.
Orchidaceae are well known for their fascinating floral morphologic features, specialized pollination, and distinctive ecological strategies. With their long-lasting flowers of various colors and ...pigmentation patterning, Phalaenopsis spp. have become important ornamental plants worldwide. In this study, we identified three R2R3-MYB transcription factors PeMYB2, PeMYB11, and PeMYB12. Their expression profiles were concomitant with red color formation in Phalaenopsis spp. flowers. Transient assay of overexpression of three PeMYBs verified that PeMYB2 resulted in anthocyanin accumulation, and these PeMYBs could activate the expression of three downstream structural genes Phalaenopsis spp. Flavanone 3-hydroxylase5, Phalaenopsis spp. Dihydroflavonol 4-reductase1, and Phalaenopsis spp. Anthocyanidin synthase3. In addition, these three PeMYBs participated in the distinct pigmentation patterning in a single flower, which was revealed by virus-induced gene silencing. In the sepals/petals, silencing of PeMYB2, PeMYB11, and PeMYB12 resulted in the loss of the full-red pigmentation, red spots, and venation patterns, respectively. Moreover, different pigmentation patterning was regulated by PeMYBs in the sepals/petals and lip. PeMYB11 was responsive to the red spots in the callus of the lip, and PeMYB12 participated in the full pigmentation in the central lobe of the lip. The differential pigmentation patterning was validated by RNA in situ hybridization. Additional assessment was performed in six Phalaenopsis spp. cultivars with different color patterns. The combined expression of these three PeMYBs in different ratios leads to a wealth of complicated floral pigmentation patterning in Phalaenopsis spp.
Evolution of Terpene Synthases in Orchidaceae Huang, Li-Min; Huang, Hsin; Chuang, Yu-Chen ...
International journal of molecular sciences,
06/2021, Volume:
22, Issue:
13
Journal Article
Peer reviewed
Open access
Terpenoids are the largest class of plant secondary metabolites and are one of the major emitted volatile compounds released to the atmosphere. They have functions of attracting pollinators or ...defense function, insecticidal properties, and are even used as pharmaceutical agents. Because of the importance of terpenoids, an increasing number of plants are required to investigate the function and evolution of terpene synthases (
s) that are the key enzymes in terpenoids biosynthesis. Orchidacea, containing more than 800 genera and 28,000 species, is one of the largest and most diverse families of flowering plants, and is widely distributed. Here, the diversification of the
s evolution in Orchidaceae is revealed. A characterization and phylogeny of
s from four different species with whole genome sequences is available. Phylogenetic analysis of orchid
s indicates these genes are divided into
,
,
and
subfamilies, and their duplicated copies are increased in derived orchid species compared to that in the early divergence orchid,
. The large increase of both
and
copies can probably be attributed to the pro-duction of different volatile compounds for attracting pollinators or generating chemical defenses in derived orchid lineages; while the duplications of
and
copies occurred in a species-dependent manner.
SUMMARY
Terrestrial plants emit volatiles into the atmosphere to attract both pollinators and the enemies of herbivores, for defense. Phalaenopsis bellina is a scented orchid species in which the ...main scent components are monoterpenes, including linalool and geraniol, and their derivatives. Here, we investigated whether ABC transporters are involved in floral scent emission. We carried out whole‐genome identification of ABC transporter‐related genes using four floral transcriptomics libraries of P. bellina. We identified 86 ABC subfamily G genes related to terpenoid transport. After comparing the gene expression patterns of P. bellina with that of Phalaenopsis aphrodite subsp. formosana, a scentless species, followed by gene‐to‐gene correlation analysis, PbABCG1 and PbABCG2 were selected. The temporal expression of both PbABCG1 and PbABCG2 was highly correlated with that of the key enzyme PbGDPS and the major transcription factor PbbHLH4 in monoterpene biosynthesis, with optimal expression on day 5 post‐anthesis. Spatial gene expression analysis showed that PbABCG1 was highly expressed in sepals, whereas PbABCG2 was expressed in the lip. Subcellular localization with a GFP fusion protein revealed that both PbABCG1 and PbABCG2 are cytoplasmic membrane proteins. Co‐downregulation of PbABCG1 and PbABCG2 using both double‐strand RNA interference and tobacco rattle virus‐based gene silencing led to a significant decrease in monoterpene emission, accompanied by an increase in the internal monoterpene pools. Furthermore, ectopic expression of PbABCG1 and PbABCG2 in an ABC16− mutant yeast strain rescued its tolerance to geraniol. Altogether, our results indicate that PbABCG1 and PbABCG2 play substantial roles in monoterpene transport/emission in P. bellina floral scent.
Significance Statement
The biosynthesis and regulation of volatile organic compounds are understood well, but the mechanism through which they are emitted to the atmosphere has remained unclear until now. We identified two PbABCG1 and PbABCG2 transporters and assessed them for involvement in the emission of monoterpene floral scent in Phalaenopsis bellina, the results suggest that PbABCG1 and PbABCG2 play a substantial role in the transport/emission of monoterpenes from flowers.
The underlying mechanism of colorectal cells developing into cancer cells has been extensively investigated, yet is still not fully delineated, resulting in the treatment of advanced colorectal ...cancer (CRC) remains regrettably an unmet need. Zinc Finger Protein 746/Parkin‐interacting substrate (ZNF746/PARIS) has previously been identified to play a fundamental role on bladder cancer cell proliferation and metastasis that were effectively inhibited by melatonin (Mel). In this study, we utilized ex vivo/in vivo studies to verify whether the ZNF746 signaling was also crucial in CRC growth/invasion/migration. Tissue‐bank specimens showed that the protein expression of ZNF746 was significantly increased in CRC than that of healthy colorectal tissues (p < 0.001). Additionally, in vitro study demonstrated that excessive expression of ZNF746 significantly inhibited mitochondrial activity via (1) interfering with the dynamic balance of mitochondrial fusion/fission and (2) inhibiting the protein expression of MFN1/MFN2/PGC1a (all p < 0.001). Furthermore, we identified that inhibition of ZNF746 protein expression significantly reduced the resistance of CRC cell lines to the anticancer drug of 5‐FU (p < 0.001), whereas overexpression of ZNF746 significantly augmented resistance of CRC cells to 5‐FU (all p < 0.001). Finally, using the cell culture method, we found that combined Mel and 5‐FU was superior to merely one on promoting the CRC cell apoptosis (p < 0.001). Our results confirmed that ZNF746 signaling played a cardinal role of CRC cell proliferation/survival and combined Mel and 5‐FU treatment attenuated the resistance of CRC cells to the drug mainly through suppressing this signaling.
Phalaenopsis represents an important cash crop worldwide. Abundant flower colors observed in Phalaenopsis orchids range from red-purple, purple, purple-violet, violet, and violet-blue. However, ...violet-blue orchids are less bred than are those of other colors. Anthocyanin, vacuolar pH and metal ions are three major factors influencing flower color. This study aimed to identify the factors causing the violet-blue color in Phalaenopsis flowers and to analyze whether delphinidin accumulation and blue pigmentation formation can be achieved by transient overexpression of heterologous F3'5'H in Phalaenopsis.
Cyanidin-based anthocyanin was highly accumulated in Phalaenopsis flowers with red-purple, purple, purple-violet, and violet to violet-blue color, but no true-blue color and no delphinidin was detected. Concomitantly, the expression of PeF3'H (Phalaenopsis equestrsis) was high, but that of PhF3'5'H (Phalaenopsis hybrid) was low or absent in various-colored Phalaenopsis flowers. Transient overexpression of DgF3'5'H (Delphinium grandiflorum) and PeMYB2 in a white Phalaenopsis cultivar resulted a 53.6% delphinidin accumulation and a novel blue color formation. In contrast, transient overexpression of both PhF3'5'H and PeMYB2 did not lead to delphinidin accumulation. Sequence analysis showed that the substrate recognition site 6 (SRS6) of PhF3'5'H was consistently different from DgF3'5'Hs at positions 5, 8 and 10. Prediction of molecular docking of the substrates showed a contrary binding direction of aromatic rings (B-ring) with the SRS6 domain of DgF3'5'H and PhF3'5'H. In addition, the pH values of violet-blue and purple Phalaenopsis flowers ranged from 5.33 to 5.54 and 4.77 to 5.04, respectively. Furthermore, the molar ratio of metal ions (including Al
, Ca
and Fe
) to anthocyanin in violet-blue color Phalaenopsis was 190-, 49-, and 51-fold higher, respectively, than those in purple-color Phalaenopsis.
Cyanidin-based anthocyanin was detected in violet-blue color Phalaenopsis and was concomitant with a high pH value and high molar ratio of Al
, Ca
and Fe
to anthocyanin content. Enhanced expression of delphinidin is needed to produce true-blue Phalaenopsis.
Phalaenopsis spp. represent the most popular orchids worldwide. Both P. equestris and P. aphrodite are the two important breeding parents with the whole genome sequence available. However, ...marker-trait association is rarely used for floral traits in Phalaenopsis breeding. Here, we analyzed markers associated with aesthetic traits of Phalaenopsis orchids by using genome-wide association study (GWAS) with the F1 population P. Intermedia of 117 progenies derived from the cross between P. aphrodite and P. equestris. A total of 113,517 single nucleotide polymorphisms (SNPs) were identified in P. Intermedia by using genotyping-by-sequencing with the combination of two different restriction enzyme pairs, Hinp1 I/Hae III and Apek I/Hae III. The size-related traits from flowers were negatively related to the color-related traits. The 1191 SNPs from Hinp1 I/ Hae III and 23 simple sequence repeats were used to establish a high-density genetic map of 19 homolog groups for P. equestris. In addition, 10 quantitative trait loci were highly associated with four color-related traits on chromosomes 2, 5 and 9. According to the sequence within the linkage disequilibrium regions, 35 candidate genes were identified and related to anthocyanin biosynthesis. In conclusion, we performed marker-assisted gene identification of aesthetic traits with GWAS in Phalaenopsis orchids.
This study tested whether combined therapy with melatonin and apoptotic adipose‐derived mesenchymal stem cells (A‐ADMSCs) offered additional benefit in ameliorating sepsis‐induced acute kidney ...injury. Adult male Sprague–Dawley rats (n = 65) were randomized equally into five groups: Sham controls (SC), sepsis induced by cecal‐ligation and puncture (CLP), CLP‐melatonin, CLP‐A‐ADMSC, and CLP‐melatonin‐A‐ADMSC. Circulating TNF‐α level at post‐CLP 6 hr was highest in CLP and lowest in SC groups, higher in CLP‐melatonin than in CLP‐A‐ADMSC and CLP‐melatonin‐A‐ADMSC groups (all P < 0.001). Immune reactivity as reflected in the number of splenic helper‐, cytoxic‐, and regulatory‐T cells at post‐CLP 72 hr exhibited the same pattern as that of circulating TNF‐α among all groups (P < 0.001). The histological scoring of kidney injury and the number of F4/80+ and CD14+ cells in kidney were highest in CLP and lowest in SC groups, higher in CLP‐melatonin than in CLP‐A‐ADMSC and CLP‐melatonin‐A‐ADMSC groups, and higher in CLP‐A‐ADMSC than in CLP‐melatonin‐A‐ADMSC groups (all P < 0.001). Changes in protein expressions of inflammatory (RANTES, TNF‐1α, NF‐κB, MMP‐9, MIP‐1, IL‐1β), apoptotic (cleaved caspase 3 and PARP, mitochondrial Bax), fibrotic (Smad3, TGF‐β) markers, reactive‐oxygen‐species (NOX‐1, NOX‐2), and oxidative stress displayed a pattern identical to that of kidney injury score among the five groups (all P < 0.001). Expressions of antioxidants (GR+, GPx+, HO‐1, NQO‐1+) were lowest in SC group and highest in CLP‐melatonin‐A‐ADMSC group, lower in CLP than in CLP‐melatonin and CLP‐A‐ADMSC groups, and lower in CLP‐melatonin‐ than in CLP‐A‐ADMSC‐tretaed animals (all P < 0.001). In conclusion, combined treatment with melatonin and A‐ADMSC was superior to A‐ADMSC alone in protecting the kidneys from sepsis‐induced injury.
The orchid industry has seen a recent surge in export values due to the floral morphology and versatile applications of orchids in various markets for medicinal, food additive, and cosmetic usages. ...However, plant-related diseases, including the yellow leaf disease caused by Fusarium solani, have caused significant losses in the production value of Phalaenopsis (up to 30%). In this study, 203 Phalaenopsis cultivars were collected from 10 local orchid nurseries, and their disease severity index and correlation with flower size were evaluated. Larger flowers had weaker resistance to yellow leaf disease, and smaller flowers had stronger resistance. For the genetic relationship of disease resistance to flower size, the genetic background of all cultivars was assessed using OrchidWiz Orchid Database Software and principal component analysis. In addition, we identified the orthologous genes of BraTCP4, namely PeIN6, PeCIN7, and PeCIN8, which are involved in resistance to pathogens, and analyzed their gene expression. The expression of PeCIN8 was significantly higher in the most resistant cultivars (A7403, A11294, and A2945) relative to the most susceptible cultivars (A10670, A6390, and A10746). We identified a correlation between flower size and resistance to yellow leaf disease in Phalaenopsis orchids. The expression of PeCIN8 may regulate the two traits in the disease-resistant cultivars. These findings can be applied to Phalaenopsis breeding programs to develop resistant cultivars against yellow leaf disease.
We tested the hypothesis that combined melatonin and autologous adipose‐derived mesenchymal stem cells (ADMSC) was superior to either alone against small bowel ischemia‐reperfusion (SBIR) injury ...induced by superior mesenteric artery clamping for 30 min followed by reperfusion for 72 hr. Male adult Sprague Dawley rats (n = 50) were equally categorized into sham‐operated controls SC, SBIR, SBIR‐ADMSC (1.0 × 106 intravenous and 1.0 × 106 intrajejunal injection), SBIR‐melatonin (intraperitoneal 20 mg/kg at 30 min after SI ischemia and 50 mg/kg at 6 and 18 hr after SI reperfusion), and SBIR‐ADMSC‐melatonin groups. The results demonstrated that the circulating levels of TNF‐α, MPO, LyG6+ cells, CD68+ cells, WBC count, and gut permeability were highest in SBIR and lowest in SC, significantly higher in SBIR‐ADMSC group and further increased in SBIR‐melatonin group than in the combined therapy group (all P < 0.001). The ischemic mucosal damage score, the protein expressions of inflammation (TNF‐α, NF‐κB, MMP‐9, MPO, and iNOS), oxidative stress (NOX‐1, NOX‐2, and oxidized protein), apoptosis (APAF‐1, mitochondrial Bax, cleaved caspase‐3 and PARP), mitochondrial damage (cytosolic cytochrome C) and DNA damage (γ‐H2AX) markers, as well as cellular expressions of proliferation (PCNA), apoptosis (caspase‐3, TUNEL assay), and DNA damage (γ‐H2AX) showed an identical pattern, whereas mitochondrial cytochrome C exhibited an opposite pattern compared to that of inflammation among all groups (all P < 0.001). Besides, antioxidant expressions at protein (NQO‐1, GR, and GPx) and cellular (HO‐1) levels progressively increased from SC to the combined treatment group (all P < 0.001). In conclusion, combined melatonin‐ADMSC treatment offered additive beneficial effect against SBIR injury.
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