Explore the vast range of titles available.

Background Accumulating evidences show that SPL s are crucial regulators of plant abiotic stress tolerance and the highly conserved module miR156/ SPL appears to balance plant growth and stress responses. The halophyte Tamarix chinensis is highly resistant to salt tress. SPL s of T. chinensis ( TcSPLs ) and theirs roles in salt stress responses remain elusive. Results In this study, we conducted a systematic analysis of the TcSPLs gene family including 12 members belonging to 7 groups. The physicochemical properties and conserved motifs showed divergence among groups and similarity in each group. The microRNA response elements (MREs) are conserved in location and sequence, with the exception of first MRE within TcSPL 5. The miR156-targeted SPL s are identified by dual-luciferase reporter assay of MRE-miR156 interaction. The digital expression gene profiles cluster suggested potential different functions of miR156-targeted SPL s vs non-targeted SPL s in response to salt stress. The expression patterns analysis of miR156-targeted SPL s with a reverse expression trend to TcmiR156 suggested 1 h (salt stress time) could be a critical time point of post-transcription regulation in salt stress responses. Conclusions Our work demonstrated the post-transcription regulation of miR156-targeted TcSPLs and transcription regulation of non-targeted TcSPLs in salt stress responses, and would be helpful to expound the miR156/ SPL -mediated molecular mechanisms underlying T. chinensis salt stress tolerance.

Background Cinnamomum camphora has been cultivated as an economically important tree for its medicinal and aromatic properties. Selective breeding has produced Cinnamomum plants for special uses, including spice strains with characteristic flavors and aromas and high-potency medicinal cultivars. The molecular biology underlying terpenoid biosynthesis is still unexplored. Results Gas chromatography-mass spectrometry was used to analyze the differences in contents and compositions of essential oil terpenoids in linalool- and borneol-type chemotypes of C. camphora . The data revealed that the essential oils consist primarily of monoterpenes with only very minor quantities of sesquiterpenes and diterpenes and that the essential oil differs in different chemotypes of C. camphora , with higher yields of (−)-borneol from the borneol-type than from the linalool-type. To study the terpenoid biosynthesis of signature compounds of the major monoterpenes, we performed RNA sequencing to profile the leaf transcriptomes of the two chemotypes of C. camphora . A total of 23.76 Gb clean data was generated from two chemotypes and assembled into 156,184 unigenes. The total length, average length, N50 and GC content of unigenes were 155,645,929 bp, 997 bp, 1430 bp, and 46.5%, respectively. Among them, 76,421 unigenes were annotated by publicly available databases, of which 67 candidate unigenes were identified to be involved in terpenoid biosynthesis in C. camphora . A total of 2863 unigenes were identified to be differentially expression between borneol-type and linalool-type, including 1714 up-regulated and 1149 down-regulated unigenes. Most genes encoding proteins involved in terpenoid precursor MVA and MEP pathways were expressed in similar levels in both chemotypes of C. camphora . In addition, 10 and 17 DEGs were significantly enriched in the terpene synthase activity and oxidoreductase activity terms of their directed acyclic graphs (DAG), respectively. Three monoterpene synthase genes, TPS14-like1, TPS14-like2 and TPS14-like3 were up-regulated in the borneol-type compared to the linalool-type, and their expression levels were further verified using quantitative real-time PCR. Conclusions This study provides a global overview of gene expression patterns related to terpenoid biosynthesis in C. camphora , and could contribute to a better understanding of the differential accumulation of terpenoids in different C. camphora chemotypes.

Plant AT-rich protein and zinc-binding protein (PLATZ) is a class of plant-specific zinc-dependent DNA-binding protein that binds to A/T-rich DNA sequences. PLATZ plays an important role in seed development, water tolerance, and cell proliferation in early plant growth. In this study, 11 GbPLATZ s were identified from the ginkgo genome with complete PLATZ-conserved domains, which represents a smaller number compared with angiosperms. Multi-species phylogenetic analysis showed that PLATZ genes were conserved in seed plants, and the 11 members were represented by four groups, among which groups I and II were closely related. Analysis of gene structures, sequence module characteristics, and expression patterns showed that GbPLATZ s were similar within and differed between groups. RNA-seq and qRT-PCR results showed that GbPLATZ s had distinct expression patterns. Most genes were associated with seed development, among which six genes were highly related. Subcellular localization experiments showed that six GbPLATZ proteins related to seed development were localized in the nucleus, suggesting that they might function as traditional transcription factors. This study provides a basis for understanding the structural differentiation, evolutionary characteristics, expression profile, and potential functions of PLATZ transcription factors in Ginkgo biloba .

In a randomized trial involving patients with advanced previously treated renal-cell carcinoma, nivolumab produced higher response rates than everolimus (25% vs. 5%) and median overall survival was longer (by 5.4 months), to more than 2 years. Each year, an estimated 338,000 new cases of renal-cell carcinoma are diagnosed worldwide, 1 and approximately 30% of patients present with metastatic disease at the time of diagnosis. 2 A number of targeted therapies have been approved for the treatment of advanced or metastatic renal-cell carcinoma. These agents include vascular endothelial growth factor (VEGF) pathway inhibitors and mammalian target of rapamycin (mTOR) inhibitors. 3 , 4 Everolimus is an mTOR inhibitor that is recommended for the treatment of advanced renal-cell carcinoma after treatment with sorafenib or sunitinib has failed. 3 – 6 Although everolimus and other agents have changed the therapeutic landscape for this disease, these . . .

Ginkgo biloba L. has a unique evolutionary status. Owing to its high medicinal and ornamental value, ginkgo has also recently become a research hotspot. However, the large genome and long juvenile period, as well as the lack of an effective genetic transformation system, have hindered gaining a full understanding of the comprehensive functions of ginkgo genes. At present, heterologous expression of genes in model plants is the primary method used in ginkgo-related research; however, these distant plant model relatives limit reliable interpretation of the results for direct applications in ginkgo breeding. To overcome these limitations, in this study, an efficient isolation and transient expression system for ginkgo protoplasts was established. A large number of intact and homogeneous ginkgo mesophyll protoplasts were isolated using 2% cellulase and 0.25% pectinase in 0.4 M mannitol. The activity of these protoplasts remained above 90% even after 24 h. Furthermore, when the concentration of the polyethylene glycol 4000 solution was 30%–40% (w/v), the transformation efficiency of the protoplasts reached 40%. Finally, the reliability of the system was verified using subcellular localization, transient overexpression, and protein interaction experiments with ginkgo genes, thereby providing a technical platform for the identification and analysis of ginkgo gene functions. The proposed method partially compensates for the limitations associated with the lack of a genetic transformation system and provides technical support to expand research on elucidating the functions of ginkgo genes.

The chloroplast genome (CPG) of Pinus massoniana belonging to the genus Pinus (Pinaceae), which is a primary source of turpentine, was sequenced and analyzed in terms of gene rearrangements, ndh genes loss, and the contraction and expansion of short inverted repeats (IRs). P. massoniana CPG has a typical quadripartite structure that includes large single copy (LSC) (65,563 bp), small single copy (SSC) (53,230 bp) and two IRs (IRa and IRb, 485 bp). The 108 unique genes were identified, including 73 protein-coding genes, 31 tRNAs, and 4 rRNAs. Most of the 81 simple sequence repeats (SSRs) identified in CPG were mononucleotides motifs of A/T types and located in non-coding regions. Comparisons with related species revealed an inversion (21,556 bp) in the LSC region; P. massoniana CPG lacks all 11 intact ndh genes (four ndh genes lost completely; the five remained truncated as pseudogenes; and the other two ndh genes remain as pseudogenes because of short insertions or deletions). A pair of short IRs was found instead of large IRs, and size variations among pine species were observed, which resulted from short insertions or deletions and non-synchronized variations between “IRa” and “IRb”. The results of phylogenetic analyses based on whole CPG sequences of 16 conifers indicated that the whole CPG sequences could be used as a powerful tool in phylogenetic analyses.

Auxin response factors ( ARF s) are important transcription factors (TFs) that are differentially expressed in response to various abiotic stresses. The important roles of ARF s and small RNA- ARF pathways in mediating plant growth and stress responses have emerged in several recent studies. However, no studies on the involvement of ARF s in tamarisk trees, which are resistant to salinity, have been conducted. In this study, systematic analysis revealed 12 TcARF genes belonging to five different groups in Tamarix chinensis . The microRNA response elements of miR160, which belongs to group I and miR167, which belongs to group III, were conserved in terms of their location and sequence. Moreover, digital gene expression profiles suggested that a potential miR167 target gene, TcARF6 , was rapidly expressed in response to salt stress. Cloning of TcARF6 revealed that TcARF6 could be an activation TF with a glutamine-rich region and expression pattern analysis revealed that the expression of TcARF6 was significantly downregulated specifically in the roots. A significant negative correlation in the expression pattern of tch-miR167/ TcARF6 indicated that this module may play a key role in the response to salt stress. Overall, these results provide basic information on the posttranscriptional regulation of TcARF6 for future investigations of the T. chinensis salt-stress response.

Ornamental crabapple is an important woody ornamental plant in the Northern Hemisphere. Its flowers, fruits, leaves and tree habit are all important ornamental characters. As there has been no research on the selection of superior parents and phenotypic variation, new varieties of ornamental crabapple are mainly selected from open-pollination progeny. In order to explore the transmission rule of ornamental traits between parents and offspring of crabapple, and to provide a basis for the selection of hybrid parents for directional breeding, 14 pairs of SSR markers were used in this study for paternity analysis of 384 offspring from 4 female parents crossed with 91 candidate male parents. And 273 offspring (71.1%) were matched with only the father at a 95% strict confidence level. We reconstructed 7 full-sib families (number of progeny ≥ 10) on the basis of the paternity analysis results. Genetic analysis of characters in the full-sib families revealed that green leaves and white flowers were dominant traits. All the hybrid offspring from the white flower (♀) × non-white flower (♂) cross produced white flowers, while 7.04% produced non-white flowers when both parents had white flowers. The results showed that white flowers might be a dominant qualitative trait in crabapple, while the depth of red was a quantitative trait. The genetic characteristics of green and non-green leaves and the depth of red of the peel were similar to flower color. Compared with the upright and spreading traits, the weeping trait was recessive. Some progeny showed an earlier blooming period, indicating the possibility of breeding for blooming period. Our findings are important for parent screening and improving the breeding efficiency of new varieties in ornamental crabapple hybridization.

Although the detailed biosynthetic mechanism is still unclear, the unique secondary metabolites of Ginkgo biloba , including ginkgolic acids (GAs) and terpene trilactones, have attracted increasing attention for their potent medicinal, physiological and biochemical properties. In particular, GAs have shown great potential in the fields of antibacterial and insecticidal activities, making it urgent to elucidate their biosynthetic mechanism. In this study, we systematically revealed the landscape of metabolic-transcriptional regulation across continuous growth stages of G. biloba seeds (GBS) based on multi-omics mining and experimental verification, and successfully identified all major types of GAs and terpene trilactones along with more than a thousand kinds of other metabolites. The phenological changes and the essential gene families associated with these unique metabolites were analyzed in detail, and several potential regulatory factors were successfully identified based on co-expression association analysis. In addition, we unexpectedly found the close relationship between large introns and the biosynthesis of these secondary metabolites. These genes with large introns related to the synthesis of secondary metabolites showed higher gene expression and expression stability in different tissues or growth stages. Our results may provide a new perspective for the study of the regulatory mechanism of these unique secondary metabolites in GBS.

The flavonoids in Ginkgo biloba L. (ginkgo) have important medicinal uses due to their antioxidant, antitumor, and blood circulation-promoting effects. However, the genetic mechanisms underlying flavonoid biosynthesis in ginkgo remain elusive. Flavonoid 3′, 5′-hydroxylase (F3′5′H) is an important enzyme in flavonoid synthesis. We detected a novel differentially expressed GbF3′5′H1 gene homologous to the F3′5′H enzyme involved in the flavonoid synthesis pathway through transcriptome sequencing. In this study, we characterized this gene, performed an expression analysis, and heterologously overexpressed GbF3′5′H1 in Populus. Our results showed that GbF3′5′H1 is abundant in the leaf and highly expressed during April. We also found four metabolites closely related to flavonoid biosynthesis. Importantly, the contents of 4′,5-dihydroxy-7-glucosyloxyflavanone, epicatechin, and gallocatechin were significantly higher in transgenic plants than in nontransgenic plants. Our findings revealed that the GbF3′5′H1 gene functions in the biosynthesis of flavonoid-related metabolites, suggesting that GbF3′5′H1 represents a prime candidate for future studies (e.g., gene-editing) aiming to optimize ginkgo flavonoid production, especially that of flavan-3-ols.