Melatonin regulates carbohydrate metabolism and defenses against Pseudomonas syringae pv. tomato DC3000 infection in Arabidopsis thaliana

Abstract

Melatonin has been reported to promote plant growth and development. Our experiments with Arabidopsis thaliana showed that exogenous applications of this molecule mediated invertase inhibitor (C/VIF)-regulated invertase activity and enhanced sucrose metabolism. Hexoses were accumulated in response to elevated activities by cell wall invertase (CWI) and vacuolar invertase (VI). Analyses of sugar metabolism-related genes revealed differential expression during plant development that was modulated by melatonin. In particular, C/VIF1 and C/VIF2 were strongly down-regulated by exogenous feeding. We also found the elevated CWI activity in melatonin-treated Arabidopsis improved the factors (cellulose, xylose, and galactose) for cell wall reinforcement and callose deposition during Pseudomonas syringae pv. tomato DC3000 infection, therefore, partially induced the pathogen resistance. However, CWI did not involve in salicylic acid (SA)-regulated defense pathway. Taken together, this study reveals that melatonin plays an important role in invertase-related carbohydrate metabolism, plant growth, and pathogen defense.

Distinct Carbon and Nitrogen Metabolism of Two Contrasting Poplar Species in Response to Different N Supply Levels

“…A higher total C concentration induced SPS and HxK activity in the leaves in Ps with abundant N supply, which indicated that C metabolism is stimulated by a sufficient N supply (Figure 3D). Indeed, it has also been shown in other plants that an increase in protein biosynthesis results in a greater demand for C skeletons [28,29]. However, the activities of HxK, CWI, and VI in the Ps roots were induced with low N supply, suggesting accelerated glycogen metabolism and respiration in the Ps roots in response to N deficiency.…”

“…However, little is known about transcriptional regulation in trees at deficient and sufficient N levels. Previous studies have detected higher expression, downregulation, or stable transcript levels of key genes involved in C/N metabolism in various poplar species in response to low and/or sufficient N levels [28,39]. The transcriptional downregulation of SUS1 and SPS in response to N deficiency indicates that C metabolism is inhibited due to a limited N supply.…”

Fructans As DAMPs or MAMPs: Evolutionary Prospects, Cross-Tolerance, and Multistress Resistance Potential

“…Furthermore, a link between melatonin and sugar metabolism and signaling has been suggested in the context of biotic stress (Zhao et al, 2015). Recently, Jiao et al (2016) isolated endophytic bacterial strains that live in the plant apoplast and secrete melatonin.…”

Melatonin Improves Waterlogging Tolerance of Malus baccata (Linn.) Borkh. Seedlings by Maintaining Aerobic Respiration, Photosynthesis and ROS Migration

“…Also, melatonin as well as its metabolites can eliminate different kinds of ROS including superoxide anion $\left({\mathrm{O}}_2^{•-}\right)$, hydrogen peroxide (H 2 O 2 ), hydroxyl radical ( • OH), singlet oxygen ( 1 O 2 ), peroxynitrite anion (ONOO - ) and nitric oxide (NO) (Tan et al, 2013). Melatonin has been reported to protect plants against a variety of abiotic and biotic stresses (Zuo et al, 2014; Liang et al, 2015; Liu et al, 2015; Shi et al, 2015a; Wang et al, 2015; Zhao et al, 2015b; Li C. et al, 2016; Xu et al, 2016). The transgenic Arabidopsis plants, ecotopically expressing melatonin synthetic gene MzASMT1 , had higher endogenous melatonin production and significantly lower ROS than that of their wild types.…”