Effectiveness of manganese foliar spraying to mitigate salt stress in ornamental cabbage: Insights into morphological, physiological biochemical adaptations and mTERF gene responses

Abstract

Salinity has been the subject of research for many years. However, salt stress studies on ornamental plants have increased recently. It is very important to determine the responses of bedding flowers, which are widely used in landscaping, to salt stress, and to strengthen the defense against stress. Ornamental cabbage (Brassica oleareacea L.) is widely used bedding flower in winter. The aim of this study was determining the effects of foliar application of manganese (Mn) on morphological, physiological, biochemical, and molecular parameters in ornamental cabbage ('Pigeon Purple F10) 0 ) under salt stress. Plants were irrigated with 4 different irrigation solutions which containing 0 [control], 75, 150 and 300 mM NaCl concentrations and Mn (4000 ppm) was sprayed to the leaves on 0, 7th and 14th days of the salt stress application. The application of manganese did alleviate the negative effects of salinity on shoot fresh weight and shoot dry weight in 75 mM NaCl plants. Ion leakage for 0 and 75 mM NaCl decreased with foliar spraying of Mn, but relative water content of plants did not change with Mn application. Lipid peroxidation (7.6 %) and H2O2 2 O 2 (hydrogen peroxide) (21.3 %) contents increased with Mn foliar spraying. Superoxide dismutase (SOD) and peroxidase activity did not change with Mn application under salinity. The highest catalase activity obtained from 150 mM (13.81 Unit g- 1 leaf) and 300 mM NaCl (16.00 Unit g- 1 leaf) which treated with Mn. Root Na content was lower with Mntreated plants when compared control plants under salt stress. Foliar spraying of Mn significantly increased the K content of the plants. Furthermore, Na/K and Na/Ca ratios which are important indicators for salt stress also decreased by Mn application under saline conditions. In addition, m TERF genes were measured by using the q-RT PCR. In most cases, mTERF expression was slightly induced by salinity, while manganese application generally led to downregulation of mTERFs. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.