UVA + B treatment affects antioxidant system and phytochemicals of parsley plant under different concentrations of Zn

Abstract

Decline in ozone layer that followed by enhanced solar UV radiation is a limiting factor for some plants. In this study the effect of UVA+UVB radiation on parsley plant was studied hydroponically at different concentrations of Zn (1.5 and 6.5 µm). UV radiation at both concentrations of Zn, slightly decreased the plant growth and significantly increased the carotenoids, flavonoids, total phenols and H 2 O 2 contents, but had no effect on chlorophylls content. At concentration of 1.5 µm of Zn, UV radiation caused significant increases in the MDA and anthocyanin contents and the activities of POD and CAT enzymes, but decreased the soluble sugars and protein contents. At concentration of 6.5 µm of Zn, UV radiation caused significant increases in the CAT activity, but had no significant effect on other parameters. Results suggest that parsley plant tolerates UVA+UVB radiation particularly at concentration of 6.5 µmof Zn.Key words: antioxidant enzymes; parsley; photochemicals; UVA + B; Zn IZVLEČEK OBRAVNAVANJE Z UVA + UVB VPLIVA NA ANTIOKSIDACIJSKI SISTEM IN KEMIZEM PETRŠILJA PRI RAZLIČNIH KONCETRACIJAH ZnTanjšanje ozonske plasti, ki mu sledi povečano UV sončevo sevanje sta omejujoči dejavnik za nekatere rastline. V tej raziskavi je bil preučevan učinek UVA+UVB sevanja na hidroponsko gojen peteršilj pri različnih koncentracijah Zn (1.5 in 6.5 µm). UV sevanje je pri obeh koncentracijah cinka rahlo zmanjšalo rast in značilno povečalo vsebnost karotenoidov, flavonoidov, celokupnih fenolov in H 2 O 2 , a brez učinka na vsebnost klorofilov. Pri koncentraciji 1.5 µm Zn, je UV sevanje povzročilo značilno povečanje vsebnosti MDA in antocianinov, povečalo je aktivnosti encimov POD in CAT, a zmanšalo vsebnost topnih sladkorjev in beljakov. Pri koncentaraciji 6.5 µm Zn je UV sevanje povzročilo značilno povečanje v aktivnosti CAT, a ni imelo značilnega učinka na ostale parametre. Rezultati nakazujejo, da peteršilj dobro prenaša UVA+UVB sevanje, še posebej pri koncentraciji 6.5 µm Zn.