can we find in plants the last hormone in the list of hormones mentioned above?
Yes.
Plants
When melatonin was identified in coffee extracts in the 1970s, it was believed to be a byproduct of the extraction process. Subsequently, however, melatonin has been found in all plants that have been investigated.
the primary high energy molecule in human metabolism is Adenosine triphosphate (ATP) what is catabolism? It is the set of metabolic processes that breaks down large molecules. which hormones are related to it? Cortisol, glucagon, adrenaline, cytokines, orexin and melatonin. what is the emotional response due to the third one? Fear. how does the first hormone related to metabolism of glucose? Cortisol stimulates the synthesis of 'new' glucose from non-carbohydrate sources; this is known as gluconeogenesis.. is process resisted by insulin? Yes. when was this substance which resists the process discovered? 1921. can it be extracted? Yes. from where? Pancreas.
Yes Yes, Melatonin can be found in plants Yes.
Melatonin Melatonin Melatonin
Plants Plants Plants
Until its identification in plants in 1987, melatonin was for decades thought to be primarily an animal neurohormone.   When melatonin was identified in coffee extracts in the 1970s, it was believed to be a byproduct of the extraction process. Until its identification in plants in 1987, melatonin was for decades thought to be primarily an animal neurohormone. When melatonin was identified in coffee extracts in the 1970s, it was believed to be a byproduct of the extraction process. 
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Melatonin [SEP] Plants
Until its identification in plants in 1987, melatonin was for decades thought to be primarily an animal neurohormone. When melatonin was identified in coffee extracts in the 1970s, it was believed to be a byproduct of the extraction process. Subsequently, however, melatonin has been found in all plants that have been investigated. It is present in all the different parts of plants, including leaves, stems, roots, fruits, and seeds, in varying proportions. Melatonin concentrations differ not only among plant species, but also between varieties of the same species depending on the agronomic growing conditions, varying from picograms to several micrograms per gram.