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Herbaceous peony (Paeonia lactiflora Pall.) is a famous flower with medicinal values, and its flowers have a number of medicinal constituents, especially flavonoids. In this study, a P. lactiflora cultivar with double colors including white outer-petal and yellow inner-petal was used as the experimental materials to perform the qualitative and quantitative analysis of flavonoids by high-performance liquid chromatograph-electrospray ionization-mass spectrometry (HPLC-ESI-MSn) and investigate the expression patterns of flavonoid biosynthetic genes using real-time quantitative polymerase chain reaction (Q-PCR). The results showed that the colors of both petals gradually weakened with flower development. Moreover, one main anthocyanin composition (peonidin 3,5-di-O-glucoside) and five main anthoxanthin compositions (kaempferol di-hexo-side, kaempferol-3-O-malonylglucoside-7-O-glucoside, quercetin-3-O-galactoside, luteolin-7-O-glucoside and isorhamnetin-3-O-glucoside) were found in the both, differing significantly in their peak areas only. Total anthocyanin, anthoxanthin and flavonoid contents in white outer-petal and yellow inner-petal gradually decreased during flower development, and were consistently higher in white outer-petal. Furthermore, the expression patterns of nine structural genes in P. lactiflora flavonoid biosynthetic pathway showed that the expression levels of phenylalanine ammonialyase gene (PIPAL), chalcone synthase gene (PICHS), flavanone 3-hydroxylase gene (PIF3H), anthocyanidin synthase gene (PIANS) and UDP-glucoside: flavonoid 5-O-glucosyltransferase gene (PIF5GT) in two petals basically presented declined tendencies, and transcription levels of PIPAL, PICHS, PIANS, PIF3GT and PIF5GT also tended to be higher in white outer-petal, which was correlated with their flavonoid contents. These results would lay a solid foundation for the exploration and utilization of flavonoid resources in P. lactiflora flowers.

We investigated the relationship between the blue-light photoreceptor cryptochrome (CRY) and melatonin biosynthesis by generating RNA interference (RNAi) transgenic rice plants that suppress the cryptochrome 1b gene (CRY1b). The resulting CRY1b RNAi rice lines expressed less CRY1b mRNA, but not CRY1a or CRY2 mRNA, suggesting that the suppression is specific to CRY1b. The growth of CRY1b RNAi rice seedlings was enhanced under blue light compared to wild-type growth, providing phenotypic evidence for impaired CRY function. When these CRY1b RNAi rice plants were challenged with cadmium to induce melatonin, wild-type plants produced 100 ng/g fresh weight (FW) melatonin, whereas CRY1b RNAi lines produced 60 ng/g FW melatonin on average, indicating that melatonin biosynthesis requires the CRY photoreceptor. Due to possible feedback regulation, the expression of melatonin biosynthesis genes such as T5H, SNAT1, SNAT2, and COMT was elevated in the CRY1b RNAi lines compared to the wild-type plants. In addition, laminar angles decreased in the CRY1b RNAi lines via the suppression of brassinosteroid (BR) biosynthesis genes such as DWARF. The main cause of the BR decrease in the CRY1b RNAi lines seems to be the suppression of CRY rather than decreased melatonin because the melatonin decrease suppressed DWARF4 rather than DWARF.

Carotenoids are natural functional pigments produced by plants and microorganisms and play essential roles in human health. Cabbage ( Brassica oleracea L. var. capitata L.) is an economically important vegetable in terms of production and consumption. It is highly nutritious and contains β-carotene, lutein, and other antioxidant carotenoids. Here, we systematically analyzed carotenoid biosynthetic genes (CBGs) on the whole genome to understand the carotenoid biosynthetic pathway in cabbage. In total, 62 CBGs were identified in the cabbage genome, which are orthologs of 47 CBGs in Arabidopsis thaliana . Out of the 62 CBGs, 46 genes in cabbage were mapped to nine chromosomes. Evolutionary analysis of carotenoid biosynthetic orthologous gene pairs among B. oleracea , B. rapa , and A. thaliana revealed that orthologous genes of B. oleracea underwent a negative selection similar to that of B. rapa . Expression analysis of the CBGs showed functional differentiation of orthologous gene copies in B. oleracea and B. rapa . Exogenous phytohormone treatment suggested that ETH, ABA, and MeJA can promote some important CBGs expression in cabbage. Phylogenetic analysis showed that BoPSYs exhibit high conservatism. Subcellular localization analysis indicated that BoPSYs are located in the chloroplast. This study is the first to study carotenoid biosynthesis genes in cabbage and provides a basis for further research on carotenoid metabolic mechanisms in cabbage.

Aspergillus section Circumdati includes 27 species, some of which are considered ochratoxin A (OTA) producers. However, there is considerable controversy about their potential OTA synthesis ability. In this work, the complete genomes of 13 species of Aspergillus section Circumdati were analyzed in order to study the cluster of OTA biosynthetic genes and the region was compared to those previously reported in A. steynii and A. westerdijkiae. The results obtained reveal that the genomes of some species in this section, including A. affinis, A. cretensis, A. elegans, A. muricatus, A. pulvericola, A. roseoglobulosus, and A. subramanianii, contain a potentially functional OTA biosynthetic cluster. Therefore, they might be able to synthesize the toxin. On the contrary, A. melleus, A. ochraceus, A. ostianus, A. persii, A. sclerotiorum, A. sesamicola, and A. westlandensis contain a truncated version of the cluster that lacks many of the genes involved in OTA biosynthesis, which might be related to their inability to produce OTA. The gain/loss pattern is different in all species, which suggests that the genetic evolution of this region might be due to independent events.

Gene elongation is a molecular mechanism consisting of an in-tandem duplication of a gene and divergence and fusion of the two copies, resulting in a gene constituted by two divergent paralogous modules. The aim of this work was to evaluate the importance of gene elongation in the evolution of histidine biosynthetic genes and to propose a possible evolutionary model for some of them. Concerning the genes hisA and hisF, which code for two homologous (β/α)8-barrels, it has been proposed that the two extant genes could be the result of a cascade of gene elongation/domain shuffling events starting from an ancestor gene coding for just one (β/α) module. A gene elongation event has also been proposed for the evolution of hisB and hisD; structural analyses revealed the possibility of an early elongation event, resulting in the repetition of modules. Furthermore, it is quite possible that the gene elongations responsible for the evolution of the four proteins occurred before the earliest phylogenetic divergence. In conclusion, gene elongation events seem to have played a crucial role in the evolution of the histidine biosynthetic pathway, and they may have shaped the structures of many genes during the first steps of their evolution.

Fungi are a prospective resource of bioactive compounds, but conventional methods of drug discovery are not effective enough to fully explore their metabolic potential. This study aimed to develop an easily attainable method to elicit the metabolic potential of fungi using Aspergillus nidulans laeA as a transcription regulation tool. In this study, functional analysis of Aspergillus nidulans laeA (AnLaeA) and Aspergillus sp. Z5 laeA (Az5LaeA) was done in the fungus Aspergillus sp. Z5. Heterologous AnLaeA-and native Az5LaeA-overexpression exhibited similar phenotypic effects and caused an increase in production of a bioactive compound diorcinol in Aspergillus sp. Z5, which proved the conserved function of this global regulator. In particular, heteroexpression of AnLaeA showed a significant impact on the expression of velvet complex genes, diorcinol synthesis-related genes, and different transcription factors (TFs). Moreover, heteroexpression of AnLaeA influenced the whole genome gene expression of Aspergillus sp. Z5 and triggered the upregulation of many genes. Overall, these findings suggest that heteroexpression of AnLaeA in fungi serves as a simple and easy method to explore their metabolic potential. In relation to this, AnLaeA was overexpressed in the fungus Penicillium sp. LC1-4, which resulted in increased production of quinolactacin A.

Background: Several MYB genes belonging to R2R3 MYB transcription factors have been used in several plant species to enhance anthocyanin production, and have shown various expression or regulation patterns. This study focused on the effect of ectopic expression of an RsMYB1 isolated from radish (Raphanus sativa) on chrysanthemum cv. ‘Shinma’. Results: The RT-PCR results confirmed that RsMYB1 regulated the expression of three key biosynthetic genes (CmF3H, CmDFR, and CmANS) that are responsible for anthocyanin production in transgenic chrysanthemum, but were not detected in the non-transgenic line. In all transgenic plants, higher expression levels of key biosynthetic genes were observed in flowers than in leaves. However, the presence of RsMYB1 in chrysanthemum did not affect any morphological characteristics, such as plant height, leaf shape or size, and number of flowers. Furthermore, no anthocyanin accumulation was visually observed in the leaves and floral tissue of any of the transgenic lines, which was further confirmed by anthocyanin content estimation. Conclusion: To our knowledge, this is the first time the role of an MYB transcription factor in anthocyanin production has been investigated in chrysanthemum.

Background and Objectives: Rare actinomycetes are a promising source of novel metabolites of pharmaceutical importance. The current study focussed on selective isolation of specific genera of rare actinomycetes and screening the isolates for biosynthetic genes particularly polyketide synthases (PKS) and non ribosomal peptide synthetases (NRPS). Materials and Methods: The soil samples were subjected to various pre-treatments like 1.5% phenol treatment, 0.3% chloramine T treatment, benzethonium chloride treatment, etc. and plated on selective media supplemented with specific antibiotics targeting rare genera of actinomycetes. The putative rare actinomycete isolates were screened for bioactivity using agar cross streak method and agar well diffusion method. The ability of the isolates to produce anti-quorum sensing compounds was tested against Serratia marcescens. The isolates were also screened for the presence of biosynthetic gene clusters associated with PKS-I, PKS-II and NRPS pathways using the degenerate primer sets K1F-M6R, KSα/KSβ and A3F-A7R, respectively. The expression of these gene clusters was tracked by physicochemical screening of the extracts of isolates using spectroscopic and chromatographic techniques. Results: In this study, 1.5% phenol treatment was found to be the most promising followed by heat treatment and chloramine treatment. Our studies showed that ISP5 agar was the best for isolation of rare genera followed by ISP7, Starch Caesin agar and ISP2 supplemented with antibiotics like gentamicin, nalidixic acid and streptomycin. Micromonospora was the most abundant genus followed by Dactylosporangium. Actinomadura, Nocardiopsis and Actinoplanes were almost equal in number. Primary screening showed that 92% of the isolates were active against one of the test organisms. Thirty seven isolates were found to produce anti-quorum sensing (QS) compounds. NRPS sequences were detected in thirty nine isolates (42.8%), whereas PKS-I and PKS-II sequences were detected in seventeen and twenty eight strains (18.6% and 30.7%), respectively. Conclusion: Nine type I and type II polyketide-producing isolates as well as six peptide-producing isolates were found. The peptide extract of isolate KCR3 and a polyketide extract of isolate NCD10 were found to possess anti-tumor activity exhibiting an IC50 value of 3 μg/ml and 2.5 μg/ml against HeLa cells.

Human Milk Oligosaccharides (HMOs) are abundant carbohydrates fundamental to infant health and development. Although these oligosaccharides were discovered more than half a century ago, their biosynthesis in the mammary gland remains largely uncharacterized. Here, we use a systems biology framework that integrates glycan and RNA expression data to construct an HMO biosynthetic network and predict glycosyltransferases involved. To accomplish this, we construct models describing the most likely pathways for the synthesis of the oligosaccharides accounting for >95% of the HMO content in human milk. Through our models, we propose candidate genes for elongation, branching, fucosylation, and sialylation of HMOs. Our model aggregation approach recovers 2 of 2 previously known gene-enzyme relations and 2 of 3 empirically confirmed gene-enzyme relations. The top genes we propose for the remaining 5 linkage reactions are consistent with previously published literature. These results provide the molecular basis of HMO biosynthesis necessary to guide progress in HMO research and application with the goal of understanding and improving infant health and development., (© 2022. The Author(s).)

Araliaceae species produce various classes of triterpene and triterpenoid saponins, such as the oleanane-type triterpenoids in Aralia species and dammarane-type saponins in Panax, valued for their medicinal properties. The lack of genome sequences of Panax relatives has hindered mechanistic insight into the divergence of triterpene saponins in Araliaceae. Here, we report a chromosome-level genome of Aralia elata with a total length of 1.05 Gb. The loss of 12 exons in the dammarenediol synthase (DDS)-encoding gene in A. elata after divergence from Panax might have caused the lack of dammarane-type saponin production, and a complementation assay shows that overexpression of the PgDDS gene from Panax ginseng in callus of A. elata recovers the accumulation of dammarane-type saponins. Tandem duplication events of triterpene biosynthetic genes are common in the A. elata genome, especially for AeCYP72As, AeCSLMs, and AeUGT73s, which function as tailoring enzymes of oleanane-type saponins and aralosides. More than 13 aralosides are de novo synthesized in Saccharomyces cerevisiae by overexpression of these genes in combination. This study sheds light on the diversity of saponins biosynthetic pathway in Araliaceae and will facilitate heterologous bioproduction of aralosides., (© 2022. The Author(s).)

Background: Using genetically modified plants as natural dispensers of insect pheromones may eventually become part of a novel strategy for integrated pest management., Results: In the present study, we first characterized essential functional genes for sex pheromone biosynthesis in the rice stem borer Chilo suppressalis (Walker) by heterologous expression in Saccharomyces cerevisiae and Nicotiana benthamiana, including two desaturase genes CsupYPAQ and CsupKPSE and a reductase gene CsupFAR2. Subsequently, we co-expressed CsupYPAQ and CsupFAR2 together with the previously characterized moth desaturase Atr∆11 in N. benthamiana. This resulted in the production of (Z)-11-hexadecenol together with (Z)-11-hexadecenal, the major pheromone component of C. suppressalis. Both compounds were collected from the transformed N. benthamiana headspace volatiles using solid-phase microextraction. We finally added the expression of a yeast acetyltransferase gene ATF1 and could then confirm also (Z)-11-hexadecenyl acetate release from the plant., Conclusions: Our results pave the way for stable transformation of plants to be used as biological pheromone sources in different pest control strategies., (© 2022. The Author(s).)

During embryogenesis of eudicots, the apical region of the embryo develops two cotyledon primordia and the shoot meristem. In Arabidopsis thaliana , this process is dependent on the functionally redundant activities of the CUP-SHAPED COTYLEDON (CUC) transcription factors, namely CUC1, CUC2, and CUC3, as well as the phytohormone auxin. However, the relationship between the CUC proteins and auxin has yet to be fully elucidated. In the present study, we examined whether the expression of auxin biosynthetic genes is dependent on CUC gene activities. Comprehensive quantitative RT-PCR analysis of the main auxin biosynthetic gene families of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS1 / TRYPTOPHAN AMINOTRANSFERASE RELATED and YUCCA ( YUC ) showed that YUC1 and YUC4 expression levels were lower in cuc double mutant embryos than the expression levels of these genes in wild type embryos. Reporter analysis also revealed that the expression of YUC1 and YUC4 in the cotyledon boundary region was reduced in cuc double mutant embryos. In contrast, the loss of function mutation in the SHOOT MERISTEMLESS gene, a shoot stem cell regulator that acts downstream of the CUC genes, did not markedly affect YUC1 expression levels. These results demonstrate that CUC genes play an important role in the regulation of auxin biosynthetic gene expression during embryogenesis; furthermore, they raise the possibility that the auxin produced by this regulation contributes to cotyledon boundary development., (© 2022 Japanese Society for Plant Biotechnology.)

Peppermint is of great economic importance, mainly due to its valuable essential oils. The present study aimed to compare the expression level of genes coding for proteins involved in the rosmarinic acid biosynthesis pathway and some physiological responses in peppermint under three levels of salinity (0, 60 and 120 mM) and two levels of thermal stresses (at 25 °C, optimal plant heat, and 35 °C, for thermal stress). The results showed that salinity at 25 °C resulted in an increased relative level of phenolic compounds, proline and antioxidant activity by 1.88, 1.92 and 2.58 times after 72 h respectively at salinity of 120 mM. Rosmarinic acid as well as soluble sugar, chlorophyll and K + /N + ratio showed a decreasing trend by 3.2, 1.8, 4.6 and 9 times after 72 h respectively at salinity of 120 mM at 35 °C. Gene expression analysis showed a significant increase in HPPR and C4H expression and a significant decrease in RAS expression in plants subjected to simultaneous stresses. The higher levels of C4H and HPPR expression indicate the roles of these genes in defense processes and the effects of phenolic compounds in inhibiting oxidative stress. Our results may help increase knowledge about the stress-dependent alterations in gene expression profiles and physiological patterns in plants. This information may be used for medicinal plant improvement programs aimed at increasing rosmarinic acid production., Competing Interests: Conflict of interestThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© Prof. H.S. Srivastava Foundation for Science and Society 2022.)