Changes of Vascular Tissue Structure and PAL Gene Expression in Bell Pepper Var California Wonder under Zinc Stress

Zinc, a co-factor in numerous enzymatic reactions and an essential micronutrient is involved in the synthesis of protein as well as the metabolism of carbohydrates, nucleic acids, and lipids. Nevertheless, it could be harmful when the plants are exposed to elevated Zn levels of the element. Bell pepper (Capsicum annuum L.) is one of the most economically significant herb species that is grown and consumed around the world. It has high nutritive values as a result of having antioxidant capacity and phytochemicals. This study was undertaken to assess the effect of different concentrations of Zn on the growth parameters, the root and shoot anatomical structure, and the phenylalanine-ammonia-lyase gene (PAL) expression in Capsicum annuum L. var California Wonder. The plants were cultivated with different concentrations of zinc nitrate, including ۲.۵, ۵, ۷.۵, ۱۰, and ۱۵ mM in a greenhouse under greenhouse conditions. The untreated plant group was considered as a control. The results showed that the elevated levels of Zn meaningfully reduced the length of shoots, petiole length, total leaf areas, and leaf frequency, particularly at the highest concentration of Zn (P<۰.۰۵). The high levels of Zn also caused microscopic structural changes in the vascular tissues of roots and shoots. The gene expression of bell pepper PAL (CapPAL), analyzed by quantitative real-time PCR (qRT-PCR), showed that the highest expression levels of CapPAL were found when plants were treated with ۷.۵ mM and ۱۰ mM zinc nitrate.

کلیدواژه ها:

Capsicum Annuum L. Phenylalanine ، Ammonia ، Lyase Phylogeny Vascular Tissue Zinc