Structure,bioavailability and physicochemical properties of icariin-soymilk nanoparticle

Soymilk is a natural nanocarrier.However,the performance of flavonoid-soymilk nano-complex remains unclear.In this work,icariin-soymilk nano-complexes(ISNCs)were successfully fabricated and characterized.The effects of high-pressure homogenization(HPH)treatment on structure and physicochemical properties of soymilk and nano-complexes were investigated.HPH treatment could significantly improve the surface hydrophobicity and interfacial activity of soymilk.The soymilk with HPH treatment could significantly improve the water solubility(20 folds),thermal stability and bioavailability of icariin.The highest encapsulation efficiency(93.28%),loading capacity(39.09μg/mg),ζ-potentia(absolute value,31.20 mV)and bioavailability(72.14%)were observed in HSI-200(200 bar of homogenization pressure).While HSI-500(500 bar of homogenization pressure)showed the smallest particle size(183.73 nm).ISNCs showed a rougher surface and an irregular lamellar structure with large amount of fine particles by using Cryo-SEM,suggesting that icariin was encapsulated in soymilk.These data supplied a novel strategy to improve the performance of icariin in functional foods.

Direct somatic embryogenesis and related gene expression networks in leaf explants of Hippeastrum ‘Bangkok Rose’

Hippeastrum, a highly diverse genus in the Amaryllidaceae family, is a valuable ornamental bulbous flowering plant. Somatic embryogenesis(SE) is an efficient method for mass production of Hippeastrum plantlets. Previous studies have been devoted to the in vitro propagation of Hippeastrum, but the SE and its regulatory networks are rarely reported. In this study, we established a direct SE method of Hippeastrum Bangkok Rose' using leaf bases as explants. MS supplemented with 1.00 mg·L^(-1)NAA +1.00 mg·L^(-1)KT + 0.25 mg·L^(-1)TDZ was the optimal medium for SE. Histological observations showed that the bipolar somatic embryo originated from the epidermal cell layer and underwent initiation,globular, scutellar and coleoptile stages. During SE, endogenous hormones of IAA, CTK, ABA, and SA were highly accumulated. Transcriptomic analysis revealed the genes encoding auxin biosynthesis/metabolic enzymes and efflux carriers were induced, while the auxin receptor of TIR1 and ARF transcriptional repressor of Aux/IAA were down-regulated and up-regulated, respectively, leading to suppression of auxin signaling. In contrast, cytokine signaling was promoted at the early stage of SE, as biosynthesis, transport, and signaling components were up-regulated.Various stress-related genes were up-regulated at the early or late stages of SE. Chromatin remodeling could also be dynamically regulated via distinct expression enzymes that control histone methylation and acetylation during SE. Moreover, key SE regulators, including WOXs and SERKs were highly expressed along with SE. Overall, the present study provides insights into the SE regulatory mechanisms of the Hippeastrum.

National botanical gardens at the forefront of global plant conservation

Global changes in land use driven by demands on food,energy,and other resources in response to a rapidly increasing human population have collectively led to escalating environmental challenges,including biodiversity loss,global warming,environmental pollution,and ecosystem degradation.At present,biodiversity is seriously threatened at global,regional,and local scales,which,in turn,threatens our own survival.Biodiversity is a global asset of immense material and non-material value,providing us with food,medicine,building materials,fiber,and the ecological environment required for our well-being and health.

Telomere-to-telomere haplotype-resolved reference genome reveals subgenome divergence and disease resistance in triploid Cavendish banana

Banana is one of the most important crops of the world.Cavendish-type bananas,which have a monospecific Musa acuminata origin(AAA),account for around half of the global banana production,thereby are of great significance for human societies.However,until now,the high-quality haplotype-resolved reference genome was still undecoded for banana cultivars.Here,we reported the telomere-to-telomere(T2T)and haplotype-resolved reference genome of‘Baxijiao’(Cavendish)consisting of three haploid assemblies.The sizes of the three haploid assemblies were estimated to be 477.16 Mb,477.18 Mb,and 469.57 Mb,respectively.Although with monospecific origins,the three haploid assemblies showed great differences with low levels of sequence collinearity.Several large reciprocal translocations were identified among chromosomes 1,4,and 7.An expansion of gene families that might affect fruit quality and aroma was detected,such as those belonging to sucrose/disaccharide/oligosaccharide catabolic processes,sucrose metabolic process,starch metabolic process,and aromatic compound biosynthetic process.Besides,an expansion of gene families related to anther and pollen development was observed,which could be associated with parthenocarpy and sterility of the Cavendish cultivar.Finally,much fewer resistance genes were identified in‘Baxijiao’than in M.acuminata,particularly in the gene clusters in chromosomes 3 and 10,providing potential targets to explore for molecular analysis of disease resistance in banana.This T2T haplotype-resolved reference genome will thus be a valuable genetic resource for biological studies,molecular breeding,and genetic improvement of banana.

The miR5810/OsMRLP6 regulatory module affects rice seedling photosynthesis

Photosynthesis affects crop growth and yield.The roles of microRNAs(miRNAs)in photosynthesis are little known.In the present study,the role of the OsNF-YB7–OsMIR5810–OsMRLP6 regulatory module in photosynthesis was investigated.The malectin-like protein gene OsMRLP6 was identified as a target gene of osa-miR5810(miR5810).Overexpression in rice of miR5810 or down-expression of OsMRLP6 resulted in reduced expression of genes involved in chloroplast development and photosynthesis and decreased net photosynthetic rate,finally leading to lower shoot biomass and grain yield.Down-expression of miR5810 and overexpression of OsMRLP6 showed the opposite effect.Overexpression of transcription factor OsNF-YB7 elevated expression of OsMIR5810 in rice seedlings by binding to its promoter.The OsNFYB7–OsMIR5810–OsMRLP6 regulatory module affects photosynthesis to mediate growth and grain yield.

Effect of the biosynthesis of the volatile compound phenylacetaldehyde on chloroplast modifications in tea (Camellia sinensis) plants

Plant volatile compounds have important physiological and ecological functions.Phenylacetaldehyde(PAld),a volatile phenylpropanoid/benzenoid,accumulates in the leaves of tea(Camellia sinensis)plants grown under continuous shading.This study was conducted to determine whether PAld production is correlated with light and to elucidate the physiological functions of PAld in tea plants.Specifically,the upstream mechanism modulating PAld biosynthesis in tea plants under different light conditions as well as the effects of PAld on chloroplast/chlorophyll were investigated.The biosynthesis of PAld was inhibited under light,whereas it was induced in darkness.The structural gene encoding aromatic amino acid aminotransferase 1(CsAAAT1)was expressed at a high level in darkness,consistent with its importance for PAld accumulation.Additionally,the results of a transcriptional activation assay and an electrophoretic mobility shift assay indicated CsAAAT1 expression was slightly activated by phytochrome-interacting factor 3-2(CsPIF3-2),which is a light-responsive transcription factor.Furthermore,PAld might promote the excitation of chlorophyll in dark-treated chloroplasts and mediate electron energy transfer in cells.However,the accumulated PAld can degrade chloroplasts and chlorophyll,with potentially detrimental effects on photosynthesis.Moreover,PAld biosynthesis is inhibited in tea leaves by red and blue light,thereby decreasing the adverse effects of PAld on chloroplasts during daytime.In conclusion,the regulated biosynthesis of PAld in tea plants under light and in darkness leads to chloroplast modifications.The results of this study have expanded our understanding of the biosynthesis and functions of volatile phenylpropanoids/benzenoids in tea leaves.

ERF5 enhances protocorm-like body regeneration via enhancement of STM expression in Dendrobium orchid

Orchid plants develop protocorms upon germination and produce protocorm-like structures called protocorm-like bodies(PLBs)from protocorms and somatic cells via tissue culture.Protocorm-like bodies have broad technical application potential in the orchid industry and their regeneration is a distinct developmental process in the plant kingdom.However,little is known about this unparalleled developmental program.In this study,we identified a PLB-abundant gene,ethylene response factor(ERF),and a transcription factor named Do ERF5,and determined its important role in PLB regeneration in Dendrobium orchid.Overexpression of Do ERF5 in Dendrobium greatly enhanced the PLB regeneration from PLB and stem explants,and upregulated the expression of WOUND-INDUCED DEDIFFERENTIATION(Do WIND)homologs and SHOOT MERISTEMLESS(Do STM),as well as the genes involved in cytokinin biosynthesis(Do IPT)and the cytokinin response factors(Do ARRs).However,silencing Do ERF5 reduced the regeneration rate of PLBs,and downregulated the expression of Do WIND homologs,Do STM and Do ARRs.We demonstrated that Do ERF5 is directly bound to the Do STM promoter and regulates its expression.In addition,overexpression of Do STM in Dendrobium orchid resulted in favorable regeneration of PLBs.Our results clarify that Do ERF5 regulates the regeneration of PLB by enhancing Do STM expression.Our findings provide new insights into how Do ERF5 mediates PLB regeneration and offers technical potential in improving clonal propagation,preservation,and the bioengineering of orchids.

Phylogenomic cytonuclear discordance and evolutionary histories of plants and animals

The field of evolutionary biology has been revolutionized by phylogenomic approaches in the last decades. However, with the ever-increasing size and scope of molecular data collection, conflicting genealogies may be yielded based on different datasets and analytical approaches, a phenomenon known as cytonuclear discordance(Figure 1A and B).

From tree to forest:Multiple carbon sink constraints

Forests are the largest carbon sinks among terrestrial ecosystems.They sequestrate carbon primarily through tree growth but are currently under severe threat from global change.Recently,Tavares et al.1 identified a crucial trait,the xylem hydraulic safety margin(HSM),for predicting the risk of drought-induced tree mortality and biomass in Amazon forests.They also found that old-growth forests with wide HSMs build more biomass,while fast-growing forests are exposed to greater hydraulic risks and have a higher mortality rate.