Melatonin alleviates aluminum-induced root growth inhibition by interfering with nitric oxide production in Arabidopsis

Abstract

Running title: Melatonin alleviates Al toxicity in Arabidopsis Highlights•Nitric reductase-and nitric oxide synthase-dependent NO production contributed to Al-induced root growth inhibition in Arabidopsis.•Al inhibits root growth by NO-mediated reduction of the cell division cycle and the quiescent center cellular activity.•External application of melatonin alleviated Al-induced root growth inhibition.•Melatonin alleviated Al toxicity through interfering with NO production.•SNAT-mediated melatonin synthesis played a critical role in Al resistance.

Melatonin delays leaf senescence of Chinese flowering cabbage by suppressing ABFs‐mediated abscisic acid biosynthesis and chlorophyll degradation

“…5 Thus, investigating whether WRKY and NAC TFs are operational nodes between melatonin and GA or ROS homeostasis during the senescence of Chinese flowering cabbage, as well as the connections of ABF, WRKY, and NAC TFs, are essential. Additionally, given that melatonin can affect ROS homeostasis, [7][8][9][10][11][12][13][14] and that ROS accumulation mediates ABA signaling, 58 it is interesting to understand the possible intimate association among ROS signaling, melatonin, and ABA signaling during leaf senescence. Resolution of these aspects will provide a more thorough understanding of the molecular model depicting melatonin-delayed leaf senescence in a much broader genetic and environmental context.…”

“…[4][5][6] Moreover, melatonin is a potent scavenger of a variety of reactive oxygen/nitrogen species (ROS/RNS) and organic radicals, and thus protects cells and tissues from oxidative damage. [7][8][9][10] Melatonin is also reported to induce ROS production in several plant biological processes such as stress tolerance, 11,12 lateral root formation, 13 and stomatal closure, 14 suggesting the complicated interactions between melatonin and ROS homeostasis.…”

Daily rhythms of phytomelatonin signaling modulate diurnal stomatal closure via regulating reactive oxygen species dynamics in Arabidopsis

“…Arabidopsis thaliana ecotype Columbia‐0 (Col‐0) was used throughout. The mutant lines used in this study were pmtr1 ( cand2‐1) , snat , and rbohD/F as we described previously . To generate PMTR1 ‐OE transgenic plants, the coding sequence of AtPMTR1 ( AtCand2 ) was cloned into the pCAMBIA1300‐35S:3 × FLAG vector at the Sac I and Kpn I sites.…”

“…The mutant lines used in this study were pmtr1 (cand2-1), snat, and rbohD/F as we described previously. 10,20 To generate PMTR1-OE transgenic plants, the coding sequence of AtPMTR1 (AtCand2) was cloned into the pCAMBIA1300-35S:3 × FLAG vector at the SacI and KpnI sites. Agrobacterium-mediated transformation of Arabidopsis was performed as described previously.…”

“…19 In Arabidopsis, genes encoding melatonin biosynthetic enzymes, namely serotonin N-acetyltransferase 1 (SNAT1), caffeate O-methyltransferase 1 (COMT1), and N-acetylserotonin methyltransferase (ASMT), have been cloned. [20][21][22] Recently, we identified the first phytomelatonin receptor (PMTR1, previously named CAND2) that regulates stomatal closure via NADPH oxidase-dependent ROS signaling pathway in Arabidopsis, 10 suggesting a possibility that this molecule is a new plant hormone. 10,19,23 Although it has been shown that the endogenous concentrations of phytomelatonin peak during darkness in Chenopodium rubrum as in vertebrates, 24,25 these observations were challenged lately as several publications found that the biosynthesis of melatonin is induced by light but decreased under darkness conditions in morning glory, 26 Arabidopsis 27 and rice.…”