Fikriye Zengin

Ghrelin in plants: What is the function of an appetite hormone in plants?

In the present work, we provide compelling evidence for the expression of a ghrelin-like peptide hormone that has only been associated with animals, in various plant tissues. Ghrelin, the appetite stimulating hormone, has been identified from a number of different species including humans, rat, pig, mouse, gerbil, eel, goldfish, bullfrog and chicken. The study here was conducted using an immunohistochemistry assay to screen whether plants have any ghrelin immunoreactivity. In this respect, Prunus x domestica L. and Marus alba were examined. Immunohistochemistry results showed that there is a strong human ghrelin immunoreactivity substance in the parenchyma cells of these plants. This was entirely unexpected since this hormone was considered to be present solely in animals. Thus, this study is the first to report the presence of a peptide with ghrelin-like activity in plants, a finding that has only been observed in the animal kingdom. RIA analysis confirmed that these plants contain significant amounts of this substance. Furthermore, reverse-phase HPLC analyses of plant extracts showed an elution characteristic of the peptide identical to that of human ghrelin. In general, fruit from both plants had higher levels of the peptide than the vegetative parts.

Exogenous Treatment with Salicylic Acid Alleviating Copper Toxicity in Bean Seedlings

The present study was carried out to examine the effects of salicylic acid (SA) on growth and some physiobiochemical attributes in bean (Phaseolus vulgaris L.) plants exposed to copper stress. Exposure to copper significantly decreased root and shoot growth, chlorophyll and protein but increased malondialdehyde (MDA), carotenoid and proline. Exogenous application of SA acid was found to alleviate negative effects generated by heavy metals like copper in plant. Salicylic acid significantly increased root and shoot growth, chlorophyll and protein. In addition SA reduced the proline, MDA and carotenoid in copper stressed plants. The data suggest that the useful effect of SA during an earlier growth period could be related to avoidance of damage caused by exposure to copper. In addition, exogenous SA may improve the tolerance of the plant to the copper toxicity.

Physiological behavior of bean (phaseolus vulgaris l.) Seedlings under metal stress

The effects of nickel, cobalt, chromium and zinc on the content of vitamins A, E and C, malondialdehyde (MDA), chlorophyll and carotenoids were investigated in bean seedlings (Phaseolus vulgaris L.) grown in Hoagland solution Control and heavy metal-treated plants were grown for ten days in Hoagland solution. Vitamin A, E, and C content were measured in primary leaves by high performance liquid chromatographic (HPLC). MDA, chlorophyll and carotenoids were measured in leaves by spectrophotometer. In heavy metal treated plants, the levels of MDA, vitamins A, E and C and carotenoids significantly increased, while chlorophyll content decreased in leaves of seedlings. The results indicate that heavy metals caused an oxidative stress in bean plants. The strongest effect on vitamins A, E and C, MDA, chlorophyll and carotenoids was found in plants exposed to nickel, followed by the sequence cobalt > chromium> zinc.

Determination of Phytochemical Contents of Avena sativa (oat) and Its Impact on Debaryomyces hansenii

In the present study fatty acids, vitamins, phytosterol, flavonoid and resveratrol contents and antimicrobial activities of Avena sativa (oat) extracts treated with Debaryomyces hansenii were determined and compared. Avena sativa is consumed as the fibrous food worldwide. It was shown that total fatty acids and vitamin contents increased significantly in A. sativa extracts prepared with D. hansenii. However, the flavonoid contents decreased at different rates. It was also observed that quercetin and flavonoids were present in the extracts that contained D. hansenii. It was noted that A. sativa had changing rates of antioxidants and antimicrobial activities. Thus, it was concluded that A. sativa has an important place in a healthy lifestyle and oats have positive effect on the development of D. hansenii which is also accepted as a probiotic microorganism. This yeast developed in extracts obtained from this fibrous plant and affected the bioactive compounds at changing rates.

Vitamin and fatty acid composition of P. eryngii var. eryngii

In this study, fatty acid and vitamin contents of P. eryngii var. eryngii grown on various agro-residue were determined. The distribution of oil acid in 100 g lipid extracted from samples were found to be 0.00-0.59 g C14:0, 0.00-1.68 g C15:0, 13.56-20.09 g C16:0, 0.00-4.98 g C16:1, 0.00-0.22 g C17:1, 1.35-5.41 g C18:0, 10.77-34.80 g C18:1, 33.06-70.39 g C18:2, 0.00-1.17 g C18:3, 0.00-0.53 g C20:0, 0.00-0.59 g C20:2, 0.00-0.25 g C20:1, 0.00-4.14 g C20:3, 0.00-0.51 g C20:5, 0.00-1.15 g C22:0, 0.00-0.30 g C22:1, 0.00-3.54 g C22:2, 0.00-0.33 g C22:4, 0.00-1.15 g C22:5, 0.00-3.93 g C22:6 and 0.00-2.07 g C24:0, of wet weight. The contents of vitamin were 0.014-0.064 A, 0.869-3.565 E, 55.980-473.405 C and 0.087-5.619 MDA mg/kg of wet weight. It has been determined that P. eryngii var. eryngii is rich from the point of view of unsaturated fatty acids such as linoleic acid, oleic acid and palmitic acid, and especially vitamins C, also antioxidants vitamins such as vitamin A, E and MDA.