Cuiying Li

Exogenous melatonin improves Malus resistance to Marssonina apple blotch

We examined whether exogenously applied melatonin could improve resistance to Marssonina apple blotch (Diplocarpon mali) by apple [Malus prunifolia (Willd.) Borkh. cv. Donghongguo]. This serious disease leads to premature defoliation in the main regions of apple production. When plants were pretreated with melatonin, resistance was increased in the leaves. We investigated the potential roles for melatonin in modulating levels of hydrogen peroxide (H2O2), as well the activities of antioxidant enzymes and pathogenesis‐related proteins during these plant–pathogen interactions. Pretreatment enabled plants to maintain intracellular H2O2 concentrations at steady‐state levels and enhance the activities of plant defence‐related enzymes, possibly improving disease resistance. Because melatonin is safe and beneficial to animals and humans, exogenous pretreatment might represent a promising cultivation strategy to protect plants against this pathogen infection.

Responses of growth and antioxidant system to root-zone hypoxia stress in two Malus species

Responses of growth and antioxidant system to root-zone hypoxia stress were comparatively studied in two Malus species (M. hupenensis and M. toringoides) differing in hypoxia tolerance. 50-day-old seedlings were hydroponically grown for 20xa0days in normoxic and hypoxic nutrient solutions. Hypoxia stress inhibited the growth of both species. Compared with M. hupenensis, M. toringoides was more responsive to hypoxia stress, resulting in larger decreases in leaf number, root length, plant height, and biomass production. The contents of superoxide radicals

Exogenous Salicylic Acid Alleviates Growth Inhibition and Oxidative Stress Induced by Hypoxia Stress in Malus robusta Rehd

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Contrasting hypoxia tolerance and adaptation in Malus species is linked to differences in stomatal behavior and photosynthesis

and hydrogen peroxide (H2O2) significantly increased in roots of both species exposed to hypoxia stress, and resulted in lipid peroxidation, which was indicated by accumulated concentration of malonaldehyde (MDA). In addition, a significant increase in

Uptake and metabolism of ammonium and nitrate in response to drought stress in Malus prunifolia

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Dopamine alleviates nutrient deficiency-induced stress in Malus hupehensis

, H2O2 and MDA contents was found in M. toringoides under hypoxia stress. In responses to hypoxia stress, peroxidse (POD), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) activities increased during the early part of the hypoxia stress, but decreased in the late period; the activities of SOD, POD and APX were more increased in M. hupenensis than in M. toringoides. Ascorbic acid (AsA) and glutathione (GSH) accumulation was also higher in M. hupenensis than in M. toringoides in the early period under hypoxia stress. These results suggest that the hypoxia-tolerant M. hupenensis has a larger protective capacity against oxidative damage by maintaining higher induced activities of antioxidant system than the hypoxia-sensitive M. toringoides.