Comparative Analysis of Leaf Trichomes, Epidermal Wax And Defense Enzymes Activities in Response to Puccinia horiana in Chrysanthemum and Ajania Species

White rust caused by Puccinia horiana is a destructive disease of chrysanthemum plants.To better understand the resistance mechanisms of composite species to this disease,the leaf cuticular traits,antioxidant and defensive enzymes activities of immune(Chrysanthemum makinoi var.wakasaense)and highly susceptible(Ajania shiwogiku var.kinokuniense)species were compared.Trichome density of two species was markedly different,negatively associated with plant resistance to P.horiana.Total wax load in C.makinoi var.wakasaense was two times more than that in A.shiwogiku var.kinokuniense.The wax composition in immune one was abundant in esters and primary alcohols.Superoxide dismutase(SOD,EC 1.15.1.1),peroxidase(POD,EC 1.11.1.7),polyphenoloxidase(PPO,EC 1.14.18.1 or EC 1.10.3.2)and phenylalanine ammonia lyase(PAL,EC 4.3.1.5)activitieswere investigated.In C.makinoi var.wakasaense,the activity of SOD and POD increased rapidly after inoculation,whichmight be non-host induced reactive oxygen species(ROS)activated antioxidant enzymes,however SOD and POD remained a low and steady level in the highly susceptible one after inoculation.Quick increase in PPO activities after inoculation was observed in both species,however it remained higher in C.makinoi var.wakasaense at the late period of inoculation.PAL in C.makinoi var.wakasaense was induced after pathogen inoculation,but not in A.shiwogiku var.kinokuniense,suggesting that these two enzymes might contribute to the resistance to P.horiana.

Contrasting responses to drought stress between Chrysanthemum japonense and C. nankingense

The response of Chrysanthemum japonense and C.nankingense to drought stress induced by polyethylene glycol was characterized at the level of leaf water status,leaf surface morphology and cuticular wax(quantity and composition),the activity of antioxidant enzymes,the extent of membrane lipid peroxidation,the accumulation of proline,photosynthesis performance and abscisic acid(ABA)accumulation.The more tolerant species C.japonense maintained its water status more effectively than C.nankingense,probably because its leaves form more cuticular wax and are able to accumulate higher levels of ABA.Superoxide dismutase activity was higher in C.japonense than in C.nankingense,as was that of catalase and ascorbate peroxidase during the later part of the stress episode,but levels of peroxidase were not differentiated at the end of the stress period.Membrane damage,as measured by electrolyte leakage and malondialdehyde accumulation,was less severe in C.japonense,which was also able to generate higher levels of free proline after a 10 h exposure to stress.Thus the superior response of C.japonense also reflects a more adapted system of osmoprotection and antioxidation.As a result,photosynthesis was compromised less by drought stress in C.japonense than in C.nankingense.That provides a scientific basis for the development and application of drought tolerance resources of chrysanthemum.

Pharmacological Activation of RXR-a Promotes Hematoma Absorption via a PPAR-y-dependent Pathway After Intracerebral Hemorrhage

Endogenously eliminating the hematoma is a favorable strategy in addressing intracerebral hemorrhage(ICH).This study sought to determine the role of retinoid X receptor-ot(RXR-a)in the context of hematoma absorption after ICH.Our results showed that pharmacologically activating RXR-a with bexarotene significantly accelerated hematoma clearance and alleviated neurological dysfunction after ICH.RXR-ot was expressed in microglia/macro-phages,neurons,and astrocytes.Mechanistically,bexarotene promoted the nuclear translocation of RXR-a and PPAR-y,as well as reducing neuroinflammation by modulating microglia/macrophage reprograming from the Ml into the M2 phenotype.Furthermore,all the beneficial effects of RXR-a in ICH were reversed by the PPAR-y inhibitor GW9662.In conclusion,the pharmacological activation of RXR-a confers robust neuroprotection against ICH by accelerating hematoma clearance and repolarizing microglia/macrophages towards the M2 phenotype through PPAR-y-related mechanisms.Our data support the notion that RXR-ot might be a promising therapeutic target for ICH.

Short-and medium-chain chlorinated paraffins in imported commercial dry cat and dog food in China:Concentrations,distributions and risk assessment

Chlorinated paraffins(CPs)are produced in large amounts and used worldwide.Dietary intake is the primary pathway for the exposure of pets to CPs,but limited information is available concerning the potential contamination of pet food by CPs.In the present study,the concentrations and congener group profiles of short-chain CPs(SCCPs)and medium-chain CPs(MCCPs)were assessed in 35 imported commercial dry cat and dog foods collected in China,and the estimated daily intakes of SCCPs and MCCPs for cats and dogs through the consumption of such foods was calculated.The concentrations of SCCPs and MCCPs in the cat and dog foods were determined to be in the ranges of 108e45,300 ng/g(median:1340 ng/g)and 3.8e52,700 ng/g(median:11 ng/g),respectively.The predominant congener groups were C10Cl6 for SCCPs and C14Cl7-8 for MCCPs.The high levels of CPs found in certain pet foods suggest the potential for adverse health effects.