ABSTRACT
ABC efflux proteins are a kind of transporters mediating diversified endogenous and exogenous efflux protein substrates across the plasma membrane by depending on the chemical energy released by ATP hydrolysis. As a vitally important functional membrane, it is widely found in various tissues and organs. The drug changes the expressions and/or functions of the transport proteins, which will affect the disposal process of substrate drugs corresponding to transporters in vivo, and finally lead to the pharmacokinetic interactions. The efflux proteins take part in the absorption, distribution, metabolism and excretion of drugs, and mainly consist of P-glycoprotein(P-gp), multidrug resistance associated protein(MRP) and breast cancer resistance protein(BCRP). The induction effect or inhibition effect of drugs on efflux protein plays a greatly significant role in the drug interaction produced by the compatibility of traditional Chinese medicine, which may be one of the important mechanisms of the theory of seven features of compatibility. In this article, the effects of seven features of compatibility on the ABC efflux transporters were reviewed, in order to reveal the roles of efflux protein in the herb-pairs compatibility, and provide new ideas for the mechanism and rationality of herb compatibility.
Subject(s)
ATP-Binding Cassette Transporters/metabolism , Medicine, Chinese Traditional , Multidrug Resistance-Associated Proteins/metabolism , Plant Preparations/pharmacology , Drug Interactions , HumansABSTRACT
The ripening fruit of two loquat (Eriobotrya japonica Lindl.) cultivars with different levels of lignin accumulation provide an intriguing example of lignification in flesh tissue. Increase in firmness as a result of lignification in ripening red-fleshed Luoyangqing (LYQ) fruit was confirmed, whereas white-fleshed Baisha (BS) fruit softened without lignification. Six cDNAs associated with the lignification pathway, i.e. EjPAL1, EjPAL2 (phenylalanine ammonia lyase, PAL, EC 4.3.1.5), Ej4CL (4-coumarate: coenzyme A ligase, 4CL, EC 6.2.1.12), EjCAD1, EjCAD2 (cinnamyl alcohol dehydrogenase, CAD, EC 1.1.1.195) and EjPOD (peroxidase, POD), were cloned from flesh tissue of LYQ fruit. Expression profiles of the six corresponding genes differed greatly in different tissues, and during fruit development and ripening in both LYQ and BS cultivars. Associated activities of PAL, 4CL, CAD, and POD enzymes were also measured. CAD and POD enzyme activities and the expression of EjCAD1 and EjPOD genes were most closely associated temporally with lignification of loquat flesh tissue. Levels of EjCAD1 transcripts were particularly aligned with changes in lignification during ripening as modified either by ethylene treatment or low temperature conditioning. The two PAL genes showed different expression patterns during fruit development, with EjPAL1 strongly expressed in mature fruit and EjPAL2 only expressed in early stages of development. In addition, EjCAD1 expression was stimulated by low temperature and may contribute to low temperature injury in the fruit. Our integrated data on lignin, monolignol precursors, and associated enzymes and genes, provide a consistent model of fruit lignification.
Subject(s)
DNA, Complementary/genetics , DNA, Plant/genetics , Eriobotrya/genetics , Fruit , Gene Expression Profiling , Lignin/metabolism , DNA Primers , Fruit/genetics , Gene Expression Regulation, Plant , Genes, PlantABSTRACT
A tissue culture system for embryogenic callus (EC) induction and plant regeneration of common bermudagrass using mature caryopsis (embryos) as explants was developed. The results showed that embryogenic calli could be induced from caryopsis with high frequency, in MS medium with 2,4-D 2.0-6.0 mg/L, and the best concentration of 2,4-D was 4.0 mg/L. The best method for maintaining EC and tissue differentiation was to subculture EC in MS+2,4-D 4.0 mg/L 1-2 times, follwed by subculturing in 1/2 MS+2,4-D 2.0 mg/L for 1-2 times, then to transfer EC to 1/2 MS without hormone for a 10-d-preregeneration in light, followed by transferring to MS+6-BA 3.0 mg/L for regeneration, with regeneration frequency 31.7%. Morphological and micro-structural differences between EC and non-embryogenic callus (NEC) were observed by electron microscope. Ultrastructrual characteristics of the EC cells are described in this paper.
