No abstract

In this study, Ca oxalate crystals were isolated from the leaves and X-ray diffraction identified them as weddelite in Crataegus pontica C. Koch, C. stevenii Polar., C. monogyna ssp. monogyna Jacq. in C. orientalis var. orientalis Pallas ex Bieb. both whewellite and weddelite crystals were found. Although there were some differences among the soluble and insoluble oxalate contents, they were not notable in the species of C. stevenii (10%; 18%), C. orientalis (12.4%; 15%), C. monogyna (12.9%; 13%), whereas in C. pontica the difference was so great with the lowest soluble (4%), and highest (28%) insoluble oxalate content. Crystals have tetragonal or prismatic shape in general but tetrahedral kinked and straight shapes were seen in C. orientalis, tetragonal aggregates in C. stevenii, and also pseudo-tetrahedral cordate (heart) shape were found in C. monogyna ssp. monogyna and C. pontica. As the crystal biomineralization is under genetic control, this characteristic hydration state of crystals of Crataegus orientalis var. orientalis must be important for systematic phylogenetics.

Stachys tmolea subsp. tmolea Boiss. is endemic to Turkey and is a species of the genus Stachys L. which is one of the largest genera of the family Lamiaceae with about 300 species. The aims of this study were to examine the chemical composition of the essential oil and n-hexane extract of S. tmolea subsp. tmolea as natural sources of insecticidal activity against the dengue vector, Aedes aegypti. Analysis of the essential oil by GC-FID and gas chromatography-mass spectrometry (GC-MS) systems identified hexahydrofarnesyl acetone (15%), viridiflorol (10%), hexadecanoic acid (7%) and 9-geranyl-p-cymene (6%) as major components. The volatile components of the n-hexane extract were extracted using headspace solid-phase microextraction (HS-SPME) and were analyzed using GC-MS. The principal constituents were 3,4-dimethyl decane (16%), 3-methyl-3-pentanol (15%), 2-methyl-2-pentanol (12%), 1,4-bis (1,1-dimethylethyl) benzene (12%), heptanal (10%), acetic acid (6%) and decane (4%). Bioassay of the n-hexane extract, at 5 µg/mosquito, produced 90% mortality against adult Ae. aegypti while the S. tmolea essential oil demonstrated 13% mortality. No larvicidal activity was observed both in essential oil and n-hexane extract. Further studies are needed to assess the adulticidal activity of the responsible compounds in the crude extract.

Niacin (Nicotinic acid, B3 vitamin) may be involved in reduction of toxic effects of boron by regulating growth metabolism. This study was designed to examine whether external niacin treatment would improve the boron mobility in carrot callus cells or not. The results showed that excess boron caused tracheary inversions in meristematic root tissue, and also a shortage was seen in tracheary lengths with boric acid treatment. Boron excess induced the plant tolerance to water stress inverting the tracheary cells. This shortage converted nearly to normal size with niacin and boron treatment together. The results showed that boron mobility induced by niacin could reduce significantly the fresh and dry weight of carrot root cells, protein and ABA content was reduced also, in contrary, external boron and boron with niacin treatment considerable increased the two factors after one month stress. Fresh weight reduction and ABA content reduction indicated that niacin treatment caused water stress on the root cells of carrot, but boron treatment and boron with niacin treatment increased drought tolerance in carrot cells by increasing the both factors. In addition, turning the conversion of the length of the trachearies to their normal size proved that niacin treatment ended the polarizing effects of boron on cell walls.