Table 1. The existing functional regulation of animal hormones on plants. Plants could respond to external stimuli by animal hormones. The dose of physiological regulation produced by the corresponding hormone on the plant has been listed. The clinical concentration of animal hormones is noted below the corresponding hormones based on previous research. In some calculations, the average weight of adult and child are considered 60 kg and 25 kg, respectively if not mentioned in the article. Considering the proportion of water in human body, we approximate the weight of 1kg human to 1L, so as to reflect intuitively the safety when using these hormones in plants on animals.
Concluding Remarks and Future Perspectives
In summary, there has been multiple regulatory effects for animal hormones on plants. Here, we summarized existing discovery about the effects of animal hormones on plants (Table 1) to show explored physiological functions of animal hormones on plants.
It is well established that some allegedly animal hormones are not unique to animals (Pasko, Sulkowska-Ziaja, Muszynska, & Zagrodzki, 2014; Hano et al., 2017). Many of them have been found naturally on plants. These animal hormones could regulate stress resistance, reproductive and photosynthetic systems in plant. Notably, some of them, such as melatonin and serotonin even have been used to improve agricultural or horticultural production and resist biotic and abiotic stress (Jiang, & Asami, 2018; Zhang et al., 2018; Debnath et al., 2019). Hopefully, it has great potential to see new approaches about them appeared to meet human demands for ornamental plants and crops. However, it is necessary to ensure the safety of animal hormones contained in these plants to the human body. We referred to clinical concentrations of some animal hormones (Table 1). Some animal hormones used in plants could reach medical concentrations theoretically in humans. This means the use of animal hormones on plants could have a potential effect on humans through food. We should be aware of possible health threats if we use animal hormones on plants in the future. But the functional and regulatory mechanisms of plants in response to animal hormones remain to be elucidated. We only draw these conclusions from theoretical clinical data with the lack of direct evidence. More research should be carried out to study the application of animal hormones in agriculture. And we are looking forward to understanding the hormonal networks systematically and the molecular mechanism of them in both plant and animal.