Nitric Oxide as a Remedy against Oxidative Damages in Apple Seeds Undergoing Accelerated Ageing

Abstract

Seed ageing is associated with a high concentration of reactive oxygen species (ROS). Apple (Malus domestica Borkh.) seeds belong to the orthodox type. Due to a deep dormancy, they may be stored in dry condition at 5 °C for a long time, without viability loss. In the laboratory, artificial ageing of apple seeds is performed by imbibition in wet sand at warm temperature (33 °C). The aim of the work was to study nitric oxide (NO) as a seed vigour preservation agent. Embryos isolated from apple seeds subjected to accelerated ageing for 7, 14, 21 or 40 days were fumigated with NO. Embryo quality was estimated by TTC and MDA tests. ROS level was confirmed by NBT staining. We analysed the alteration in transcript levels of CAT, SOD and POX. NO fumigation of embryos of seeds aged for 21 days stimulated germination and increased ROS level which correlated to the elevated expression of RBOH. The increased total antioxidant capacity after NO fumigation was accompanied by the increased transcript levels of genes encoding enzymatic antioxidants, that could protect against ROS overaccumulation. Moreover, post-aged NO application diminished the nitro-oxidative modification of RNA, proving NO action as a remedy in oxidative remodelling after seeds ageing.

Nitric oxide–an antidote to seed aging modifies meta-tyrosine content and expression of aging-linked genes in apple embryos

“…cv. Antonówka) seeds subjected to the accelerated aging protocol according to Ciacka et al (2022) were used. The ripened apple fruits were obtained from the WIKPOL fruit producer (Da̧browa, Poland).…”

“…After aging, seeds were removed from the sand, rinsed with water, and the embryos were isolated. The embryos, treated with NO, were shortly fumigated with vapors of a solution of acidified nitrite [14.5 mM NaNO 2 (Chempur 117926907), 0.2 M HCl] for exactly 3 h as described by Ciacka et al (2022) . After NO fumigation, the embryos were rinsed in distilled water.…”

“…Conditions of warm stratification are similar to those described in accelerated aging protocols. Our previously published data have shown that keeping dormant apple seeds in wet sand at 33°C for 14 and 21 days may be successfully used to achieve material for studies of seed artificial aging ( Ciacka et al, 2022 ). We have proven that NO may be regarded as a remedy against oxidative damages in the apple seeds undergoing accelerated aging ( Ciacka et al, 2022 ).…”

“…In the embryos of aged apple seeds, a stimulation of the total antioxidant capacity after NO fumigation was demonstrated. It was accompanied by increased transcript levels of genes encoding enzymatic antioxidants, resulting in the protection of the embryonic tissue against overaccumulation of ROS ( Ciacka et al, 2022 ). In addition, we have analyzed in detail many aspects of ROS action in seeds during artificial aging and its changes in response to NO treatment ( Ciacka et al, 2022 ).…”

“…It was accompanied by increased transcript levels of genes encoding enzymatic antioxidants, resulting in the protection of the embryonic tissue against overaccumulation of ROS ( Ciacka et al, 2022 ). In addition, we have analyzed in detail many aspects of ROS action in seeds during artificial aging and its changes in response to NO treatment ( Ciacka et al, 2022 ). Thus, in the current research, we have decided to measure the content of meta -tyrosine ( m -Tyr), the structural Tyr isomer, which is a product of the oxidation of phenylalanine (Phe).…”