D6 protein kinase in root xylem benefiting resistance to Fusarium reveals in fection and defense mechanisms in tung trees

Fusarium oxysporum,a global soil-borne pathogen,causes severe disease in various cultivated plants.The mechanism underlying infection and resistance remains largely elusive.Vernicia fordii,known as the tung tree,suffers from disease caused by F.oxysporum f.sp.fordiis(Fof-1),while its sister species V.montana displays high resistance to Fof-1.To investigate the process of infection and resistance ability,we demonstrated that Fof-1 can penetrate the epidermis of root hairs and then centripetally invade the cortex and phloem in both species.Furthermore,Fof-1 spread upwards through the root xylem in susceptible V.fordii trees,whereas it failed to infect the root xylem in resistant V.montana trees.We found that D6 PROTEIN KINASE LIKE 2(VmD6PKL2)was speci fically expressed in the lateral root xylem and was induced after Fof-1 infection in resistant trees.Transgenic analysis in Arabidopsis and tomato revealed that VmD6PKL2 signi ficantly enhanced resistance in both species,whereas the d6pkl2 mutant displayed reduced resistance against Fof-1.Additionally,VmD6PKL2 was identi fied to interact directly with synaptotagmin(VmSYT3),which is speci fically expressed in the root xylem and mediates the negative regulation responding to Fof-1.Our data suggested that VmD6PKL2 could act as a resistance gene against Fof-1 through suppression of VmSYT3-mediated negative regulation in the lateral root xylem of the resistant species.These findings provide novel insight into Fusarium wilt resistance in plants.

Antimicrobial activity of essential oils extracted from Litsea cubeba

Litsea cubeba(Lour.)Pers.(Lauraceae),also known as May Chang tree or Chinese pepper,is frequently utilized for its essential oil,which is widely used in flavors,perfumes,and antimicrobials.Despite its myriad of uses,the stability and diversity of the various chemical components of L.cubeba oil have not been sufficiently investigated.Here,we utilized 31 families planted in a test forest.The stability of the essential oil content in each family was assessed over a four-year period.The chemical profiles of the essential oils from the 31 families were established.A total of 103 components were identified,with approximately 30 components found per family.Additionally,the antifungal and antibacterial activities were investigated,with significant variations found among families.The most abundant component was citral,which has previously been shown to possess antifungal activities.In addition,inhibition rates,EC50,and MIC values were measured,and the F7,G3,G4,and F9 families were found to manifest significantly stronger antifungal activity,with inhibition rates above 91%at a concentration of 250μL/L.The F7,G3,G4,and L24 families possessed strong antibacterial activity on gram-negative bacteria at a concentration of 50μL/mL.In summary,we assessed the chemical profiles of L.cubeba essential oil for different families and found that there were significant differences in essential oil components and antibacterial activities among families.Our results suggest that L.cubeba families can be further selected to improve their industrial applications and increase the quality of essential oils extracted from them.

The camphor tree genome enhances the understanding of magnoliid evolution

Magnoliids represent the third largest branch of the most diverse and species-rich angiosperms,and their phylogenetic position relative to monocots and eudicots remains uncertain(Dong et al.,2021).Here,we describe the assembly of a high-quality chromosome-level genome sequence for Cinnamomum camphora(camphor),an evergreen tree belonging to Lauraceae.Genomebased phylogenetic analysis indicated possible incomplete lineage sorting(ILS)during the rapid diversification of the early diverging branches of angiosperms,which may have led to the unstable phylogenetic position of magnoliids.

An optimization of ultra-sonication-assisted extraction from flowers of Apocynum venetum in targeting to amount of free amino acids determined by UPLC-MS/MS

Amino acids are naturally occurring compounds in many edible or medicinal plants,which possess a variety of nutraceutical effects in human.Here,a method of ultrasound-assisted extraction was optimized using Box-Behnken design of response surface methodology in maximizing the yield of free amino acids deriving from flowers of Apocynum venetum L.Under the optimal condition of ultrasound-assisted extraction,i.e.187.5 W of ultrasonic power,31.93 min of extraction time,and 0.47 mg/ml of solid-liquid ratio,the experimental yield of extractive was 287.17±0.205 mg/g,which was in close agreement with the value,as predicted by the established model.In addition,a hydrophilic interaction ultra-high performance liquid chromatography coupled with QqQ-MS/MS method was developed and validated for simultaneous quantification of 20 types of amino acids without derivatization contained in A.venetum flowers.The analytical method was validated by matrix effect,linearity,limit of detection,limit of quantification,precision,repeatability,stability,and recovery.The analysis results showed that A.venetum flower was rich in free amino acids of~3%of total dried weight,and which contained leucine(13.7 g/mg),isoleucine(7.9 g/mg),and lysine(2.2 g/mg)as the most abundant amino acids.Thus,A.venetum flower could provide beneficial nutrient values for human health,e.g.adult weight maintenance or glucose homeostasis.