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Tung tree (Vernicia fordii) as an important industrial raw material used to produce tung oil in China. Genetic transformation system has not been established for the tung tree, hindering research on the functions of tung tree genes and the cultivation of new stress-resistant varieties. In this study, we optimized the tissue culture regeneration system of tung tree hypocotyls, screened out a callus state suitable for Agrobacterium tumefaciens infection, and improved the efficiency of genetic transformation. RNA interference (RNAi) vector was constructed using FAD2 as the target gene. Adventitious shoots were obtained by infecting the hypocotyl calli cultured for 25 days through Agrobacterium -mediated infection. The positive adventitious shoot transformation rate of the pBI121 vector was 22.86%, and the adventitious shoot transformation rate of the RNAi vector was 7.84%. We established a complete genetic transformation system using two vectors, and the system was verified via GUS staining and real-time fluorescence quantitative analyses to ensure its stability. This system solves the technical problem of a genetic transformation system for the tung tree, and will provide technical support for studying the functions of tung tree genes and molecular breeding. • The efficient regeneration system of tung tree hypocotyl in vitro was optimized. • The optimal callus tissue morphology and culture time of tung tree hypocotyl suitable for Agrobacterium infection were proven. • The transgenic adventitious shoots of tung tree were obtained through RNAi technology, with a transformation rate of 7.84%. [ABSTRACT FROM AUTHOR]

As a macromolecular substance, sucrose contributes to the plant growth and development. SWEET genes, a group of sugar transporters, are a recently found plant gene family and play important roles in sugar efflux, pollen nutrition, nectar secretion, phloem transport, and seed development. The SWEET genes have been identified and characterized in some plants, but the systematic study in tung tree (Vernicia fordii) was limited. Here, we identified 121 SWEETs in five Euphorbiaceae, and could be divided into four classes with 20 different motifs. Multiple sequence alignment revealed seven transmembrane helixes (TMHs) in the SWEET proteins which were created by an internal duplication of an ancestral three-TMHs unit, connected by TMH4. This study provides direct evidence for the first time for internal duplication in Euphorbiaceae. The large-scale duplication events represented the main driving force for SWEET family expansion in Euphorbiaceae. In addition, we determined the key VfSWEETs for sucrose transport from source to sink tissues in V. fordii and proposed a possible sucrose transport model, which would be helpful for understanding the mechanism of sucrose transport in V. fordii. This study provided a new insight into the evolution, expression and structural variations of SWEETs in V. fordii and four other Euphorbiaceae. [ABSTRACT FROM AUTHOR]

Abstract: Two genes and the corresponding cDNAs for NADH:cytochrome b 5 reductase (VfCBR1A and VfCBR1B) from tung (Vernicia fordii) were cloned and characterized. Both tung genes are expressed at similar levels in various organs throughout the plant, but differ substantially in their genomic architecture. Phylogenetic comparisons of many cloned and putative CBR genes from plants and yeast revealed two general classes of sequences. The separation of the classes likely reflects differences in the subcellular targeting of the two types of proteins. Immunofluorescence analyses of tobacco BY-2 cells containing transiently expressed tung CBR1A, CBR1B, or Arabidopsis thaliana CBR revealed definitive targeting of the proteins to the endoplasmic reticulum while a previously uncharacterized Arabidopsis CBR protein was targeted specifically to mitochondria. After overexpression in Saccharomyces cerevisiae, VfCBR1A was enzymatically active, and like its Arabidopsis ortholog, displayed strict specificity for NADH as the reductant. The subcellular localization and biochemical properties of the tung enzymes are consistent with a potential role in fatty acid desaturation and conjugation. [Copyright &y& Elsevier]

Leucine-rich repeat receptor-like protein kinases (LRR-RLKs) are vital for plant growth and development, signal transduction, immunity, and play diverse roles in plant defense responses. However, the LRR-RLK genes have not been systematically studied in Vernicia fordii (tung tree), especially its response to Fusarium wilt. Here, we carried out an integrative analysis of LRR-RLKs among five Euphorbiaceae species: Hevea brasiliensis (rubber tree), Manihot esculenta (cassava), Jatropha curcas (physic nut), Ricinus communis (castor bean), and V. fordii , which contained 223, 311, 186, 138, and 167 LRR -RLKs , respectively. Maximum-likelihood tree was estimated using LRR-RLKs of Arabidopsis thaliana as a template, and they allowed us to divide Euphorbiaceae LRR-RLKs into 22 groups. There are 126 segmental and 30 tandem duplications in these Euphorbiaceae genomes by synteny analysis. The tissue-specific expression patterns revealed that V. fordii LRR-RLKs (VfLRR-RLKs) were differentially expressed in various tissues, and some of them exhibited specific expression in meristems tissues, which suggested their potential functions during organ formation and cell fate specification. Two VfLRR-RLK pairs (Vf01G2125 and Vf03G1740 , Vf06G2687 and Vf10G1659), which generated by tandem duplication events, were associated with possible resistance to Fusarium wilt infection. The qRT-PCR confirmed these four VfLRR-RLKs contained opposite expression profiles during pathogen infection in V. fordii and V. montana. Taken together, our data systematically analyzed the LRR-RLK family in Euphorbiaceae genomes for the first time. We highlight the putative roles of VfLRR-RLKs in response to Fusarium wilt infection, and VfLRR-RLKs may be further applied in marker-assisted breeding to control Fusarium wilt in V. fordii. An extensive identify was carried out in five Euphorbiaceae genomes to draw up the complete list of Leucine-rich repeat receptor-like protein kinases (LRR-RLKs) present in these organisms. Phylogenetic studies and expression patterns were used to systematically investigate the evolution of LRR-RLKs , and the putative roles of VfLRR-RLKs in response to F usarium wilt infection. [Display omitted] • Totally, 1025 LRR-RLKs were identified from five Euphorbiaceae genomes, and 126 of which came from Vernicia fordii. • Maximum-likelihood tree was estimated and they allowed us to divide Euphorbiaceae LRR-RLKs into 22 groups. • The tissue-specific expression patterns of VfLRR-RLKs suggested their potential functions during organ formation and cell fate specification. • Two VfLRR-RLK pairs, which generated by tandem duplication events, were associated with possible resistance to Fusarium wilt infection. [ABSTRACT FROM AUTHOR]

Eight previously undescribed and 15 known components, including six neolignans, two monolignan, three sesquineolignans, three dineolignans, eight phenylpropanoids, and one steroid were identified from the seed testa of Vernicia fordii. Their structures were established based on the comprehensive analysis of NMR and ECD data. The anti-neuroinflammatory effects of the isolates were evaluated through nitrite assays in LPS-induced BV2 cells. As a result, isodiverniciasin A, diverniciasin B, diverniciasin C, isoprincepin, princepin, 3, 3′-bisdemethylpinoresinol, (+)-7-epi-sesamin-dicatechol, isoamericanin A, americanin B, 7 S , 8 R -americanin D, 4-hydroxyl cinnamic aldehyde, 3-hydroxyl-4-methoxyl cinnamic aldehyde and 24 R -6 β -hydroxy-24- ethylcholest-4-en-3-one exhibited significant inhibitory effects on nitric oxide (NO) production and isoprincepin, princepin, americanin B, and 4-hydroxyl cinnamic aldehyde suppressed the overexpression of inflammatory cytokines TNF-α, IL-1β, and IL-6 in over-activated microglia. The results suggested that bioactive ingredients from the seed testa of V. fordii can serve as potential therapeutic agents for neurodegenerative diseases. Twenty-three components, including eight undescribed ones, were identified from the seed testa of Vernicia fordii (Hemsl.) Airy Shaw (Euphorbiaceae). Some of the isolates showed anti-neuroinflammatory effects in activated microglia cells. Image 1 • Eight previously undescribed and fifteen known compounds were isolated from Vernicia fordii. • Twenty three compounds from Vernicia fordii showed inhibitory effects on nitric oxide production in over-activated microglial. • A plausible biosynthetic pathway was proposed. [ABSTRACT FROM AUTHOR]