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.
Department of Biochemistry and Clinical Biochemistry, School of Medicine, Firat University, Firat Medical Center, 23119 Elazig, Turkey. saydin1@hotmail.com
Suleyman
S
Aydin
Hikmet
H
Geckil
Fikriye
F
Zengin
H
H
Ibrahim Ozercan
Fikret
F
Karatas
Suna
S
Aydin
Dilek
D
Turgut-Balik
Yusuf
Y
Ozkan
Ferda
F
Dagli
Venhar
V
Celik
D002851:Chromatography, High Pressure Liquid; D018506:Gene Expression Regulation, Plant; D054439:Ghrelin; D006728:Hormones / Q000378:metabolism*; D007150:Immunohistochemistry; D036361:Peptide Hormones / Q000378:metabolism / Q000502:physiology*; D010944:Plants / Q000378:metabolism; D027861:Prunus / Q000378:metabolism; D011863:Radioimmunoassay; D013997:Time Factors
D054439:Ghrelin; D006728:Hormones; D036361:Peptide Hormones