Genome-wide identification and characteristic analysis of the downstream melatonin metabolism gene GhM2H in Gossypium hirsutum L.

Abstract

Background Melatonin 2-hydroxylase (M2H) is the first enzyme in the catabolism pathway of melatonin, which catalyzes the production of 2-hydroxymelatonin (2-OHM) from melatonin. The content of 2-hydroxymelatonin in plants is much higher than that of melatonin. So M2H may be a key enzyme in the metabolic pathway of melatonin. Method We conducted a systematic analysis of the M2H gene family in Gossypium hirsutum based on the whole genome sequence by integrating the structural characteristics, phylogenetic relationships, expression profile, and biological stress of the members of the Gossypium hirsutum M2H gene family. Result We identified 265 M2H genes in the whole genome of Gossypium hirsutum, which were divided into 7 clades (clades I-VII) according to phylogenetic analysis. Most M2H members in each group had similar motif composition and gene structure characteristics. More than half of GhM2H members contain ABA-responsive elements and MeJA-responsive elements. Under different stress conditions, the expression levels of the gene changed, indicating that GhM2H members were involved in the regulation of abiotic stress. Some genes in the GhM2H family were involved in regulating melatonin levels in cotton under salt stress, and some genes were regulated by exogenous melatonin. Conclusion This study is helpful to explore the function of GhM2H, the downstream metabolism gene of melatonin in cotton, and lay the foundation for better exploring the molecular mechanism of melatonin improving cotton's response to abiotic stress.

Identification of SNAT Family Genes Suggests GhSNAT3D Functional Reponse to Melatonin Synthesis Under Salinity Stress in Cotton

“…Whether it is involved in melatonin synthesis needs further verification. Cotton regulated melatonin levels through a complex pathway, which was regulated not only by synthetic genes but also by downstream metabolic genes ( Zhang et al, 2021b ). In this study, GhSNAT3D may interact with GhSNAT25D , ASMT and AAS to regulate melatonin synthesis.…”

Genetic and evolutionary dissection of melatonin response signaling facilitates the regulation of plant growth and stress responses

“…22 GhM2H149 showed increased cold tolerance of cotton and GhM2H155 only exhibited sensitive to heat stress. 21 While M3H knockout mutant had no difference with WT in salt tolerance. 306 For plant growth, the M2H RNAi rice exhibited reduced germination rate, retarded growth without erect leaf, and delayed leaf senescence, while the ectopic overexpressing rice M2H in tobacco showed dwarfism, leaf necrosis, and early senescence.…”

“…20 M2H, the first gene in the melatonin catabolism pathway, could protect the plant from abiotic stress, especially salt tolerance of rice and cotton. 21,22 Gene families regulating melatonin biosynthesis, signaling, and metabolism have dramatically expanded and diversified since 1993. Therefore, investigating the genetic differentiation and functional diversity of the melatonin response gene network may help biologists to open new paradigms of melatonin's potential in plant biological process.…”

“…CAND2/PMTR1, the first plant melatonin receptor, is required for melatonin‐mediated drought tolerance and alleviation of darkness‐induced leaf senescence and stomatal closure 20 . M2H , the first gene in the melatonin catabolism pathway, could protect the plant from abiotic stress, especially salt tolerance of rice and cotton 21,22 . Gene families regulating melatonin biosynthesis, signaling, and metabolism have dramatically expanded and diversified since 1993.…”

Melatonin Induced Cold Tolerance in Plants: Physiological and Molecular Responses

“…The increase in expression of the oAANAT gene enhanced the MT contents and promoted the plant growth and spike length of switchgrass under cold stress ( Yuan et al, 2016 ). In cotton crops, over-expression of GhM2H gene improved the tolerance against heat and cold stress by increasing endogenous MT contents and antioxidant activities and reducing ABA accumulation ( Zhang Y. et al, 2021 ).…”