Exogenous melatonin confers cold tolerance in rapeseed (Brassica napus L.) seedlings by improving antioxidants and genes expression

Abstract

Rapeseed ( Brassica napus L.) is an important oilseed crop globally. However, its growth and production are significantly influenced by cold stress. To reveal the protective role of exogenous melatonin (MEL) in cold tolerance, rapeseed seedlings were pretreated with different concentrations of MEL before cold stress. The results indicated that the survival rate was increased significantly by the MEL pretreatment under cold stress. Seedlings pretreated with 0.01 g L −1 MEL were all survived and were used to analyze the physiological characteristics and the expression level of various genes related to cold tolerance. Under cold stress, exogenous MEL significantly increased the contents of proline, soluble sugar, and soluble protein; while the malondialdehyde content was decreased by exogenous MEL under cold stress. On the other hand, the activities of antioxidant defense enzymes such as catalase, peroxidase, and superoxide dismutase were also significantly enhanced. The results also showed that MEL treatment significantly upregulated the expression of Cu-SOD, COR6.6 ( cold-regulated), COR15 , and CBFs ( C-repeat binding factor ) genes under cold stress. It was suggested exogenous MEL improved the content of osmotic regulatory substances to maintain the balance of cellular osmotic potential under cold stress and improved the scavenging capacity of reactive oxygen species by strengthening the activity of antioxidant enzymes and the cold-related genes expression.

Assessment of proline function in higher plants under extreme temperatures

“…2019; Ritonga & Chen 2020; Lei et al . 2022). Nonetheless, plant response depends on various factors, including signal perception and transduction (Ganeshan et al .…”

“…ROS substantially increase under CS, causing significant damage to proteins, lipids and cellular structures (Hassan et al 2021;Mittler et al 2022). Plants activate antioxidant defence systems to cope with the deleterious impacts of CS (Sun et al 2019;Ritonga & Chen 2020;Lei et al 2022). Nonetheless, plant response depends on various factors, including signal perception and transduction (Ganeshan et al 2008).…”

The comparative effects of manganese nanoparticles and their counterparts (bulk and ionic) in Artemisia annua plants via seed priming and foliar application

“…Antioxidant enzymes have been mainly reported to be the first line of defensive and protective mechanisms against any environmental factor such as abiotic stresses ( Lei et al., 2022 ; Mittler et al., 2022 ; Najafi-Kakavand et al., 2022 ; Rahman et al., 2022 ; Raza et al., 2022a ; Raza et al., 2022b ; Shahid et al., 2022 ; Shaukat et al., 2022 ; Bhardwaj et al., 2023 ). At first, the superoxide radicals are converted to H 2 O 2 by SOD activity which can be further decomposed into H 2 O by CAT and peroxidases ( Hasanuzzaman et al., 2020 ).…”

An in Vitro Approach to Investigate the Role of Abscisic Acid in Alleviating the Negative Effects of Chilling Stress on Banana Shoots

“…Previous studies showed that the increase in endogenous ABA content was closely related to the increase in chilling tolerance [18,19]. Exogenous application of ABA increased the chilling tolerance of different plant species, including Stylosanthes guianensis [10], Cucumis melo [20], and Zea mays [21]. ABA plays a major role in the stimulation of endogenous changes relating to cold acclimation [13,22].…”

“…Exposure to low temperatures induces oxidative stress through the accumulation of reactive oxygen species (ROS) [8,9]. Plants have evolved an efficient defense system against oxidative stress via enzymatic and non-enzymatic antioxidants [8][9][10]. Abscisic acid (ABA) is a key regulator of many aspects of plant growth and development in higher plants, such as the maturation of embryos, the dormancy of seeds, the development of flowers, and the growth of roots [11].…”