Effects of Melatonin on Anti-oxidative Systems and Photosystem II in Cold-Stressed Rice Seedlings

Abstract

Melatonin (N-acetyl-5-methoxytryptamine) plays important role in multiple plant developmental processes and stress responses. We investigated the possible mediatory role of melatonin in growth, photosynthesis, and the response to cold stress in rice by using three different experiments: soaking seed; immersing roots, and spraying to leaves with 0, 20, or 100 μM melatonin. After 6 days of cold stress, the growth of rice seedlings was significantly inhibited, but this inhibition was alleviated by exogenous melatonin. Furthermore, exogenous melatonin pretreatment alleviated the accumulation of reactive oxygen species, malondialdehyde and cell death induced by cold stress. Melatonin pretreatment also relieved the stress-induced inhibitions to photosynthesis and photosystem II activities. Further investigations showed that, antioxidant enzyme activities and non-enzymatic antioxidant levels were increased by melatonin pretreatments. The treatment methods of seed soaking and root immersion were more effective in improving cold stress resistance than the spraying method. The results also indicated the dose-dependent response of melatonin on rice physiological, biochemical, and photosynthetic parameters.

Integrative roles of nitric oxide and hydrogen sulfide in melatonin‐induced tolerance of pepper (Capsicum annuum L.) plants to iron deficiency and salt stress alone or in combination

“…F). These findings are analogous to those reported by Han et al () in cold‐stressed rice, by Wang et al () in drought‐stressed apple and by Zhang et al () in water‐stressed cucumber.…”

Effect of Low Temperature on Chlorophyll Biosynthesis and Chloroplast Biogenesis of Rice Seedlings during Greening

“…Temperature is one of the major environmental factors that can inhibit chlorophyll biosynthesis and chloroplast biogenesis, and thus affect photosynthesis [31][32][33]. Our previous study also showed that cold stress dramatically decreases the net photosynthetic rate, stomatal conductance, intercellular CO 2 concentration, and water use efficiency in rice seedlings [34]. In this study, our results demonstrated that chlorophyll was significantly increased with the period of light exposure during greening at 28 • C ( Figure 2C).…”

“…At the same time, our observations showed that leaf cell death was significantly increased under the cold-stress condition during greening (Figure 10). Proline and soluble sugars served as osmoprotectants against oxidative damage, which are also considered indicators to assess the potential cold tolerance of plants [34]. Our previous study indicated that proline and soluble sugar accumulation is enhanced in cold-stressed rice seedlings [34].…”

ATP Hydrolysis Determines Cold Tolerance by Regulating Available Energy for Glutathione Synthesis in Rice Seedling Plants

“…It has been reported that cold stress occurring at reproductive phase can result in a large reduction in grain yield (Thakur et al 2010;Ghadirnezhad and Fallah 2014). Additionally, slow seedling development, yellowing, withering, reduced tillering and stunted growth are always observed under cold stress at the seedling stage (Su et al 2010;Bonnecarrère et al 2011;Han et al 2017;Cong Dien and Yamakawa 2019). As a result, the cultivated area of early rice and double-season late rice is significantly reduced in China (Sun and Huang 2011;Yu et al 2012;Wang et al 2019).…”