Ecological Implications of Plant Secondary Metabolites - Phytochemical Diversity Can Enhance Agricultural Sustainability

Abstract

Conventional agriculture production, although proficient in feeding an expanding human population, is having negative environmental impacts that are diminishing the sustainability of natural resources. Producers and consumers are increasingly interested in understanding how land management practices can enhance agricultural sustainability and improve human health. This perspective article offers a new approach to enhancing agricultural sustainability by growing crops and forages with diverse plant secondary metabolites (PSMs). Plants produce tens of thousands of PSMs to mediate interactions with soil, other plants, and animals. Plants use these metabolites to communicate with organisms in their environment, both above and belowground, and to modify the rhizosphere and influence chemical, physical, and biological attributes of soil. In pastures and rangelands, animal health benefits and production increases when animals ingest forages with different PSMs, which has implications for enhancing the biochemical richness of meat and dairy products for human consumption. A deeper understanding of PSMs, and their functional roles in agroecology, may help producers better manage their lands, reduce inputs, and minimize negative environmental impacts.

Methods for Rapid Screening of Biologically Active Compounds Present in Plant-Based Extracts

“…Natural products are successfully used in cosmetic, phytotherapy, and food-additive applications [ 44 ]. Plant secondary metabolites (e.g., terpenes, flavonoids, phenolic and polyphenolic compounds, nitrogen-containing and sulphur-containing compounds) also play a significant ecological role in crop defence (against, for example, bacteria, fungi, herbivores, plants, viruses), attraction and stimulation (e.g., nutrient sequestration, pollination), and counter abiotic stresses [ 18 ].…”

“…Primary plant constituents (e.g., sugars, proteins, amino acids, chlorophyll, and purines and pyrimidines of nucleic acids) are principally nutritional substances of plants and, in most cases, do not possess medicinal properties. Secondary plant constituents (secondary metabolites) such as alkaloids, carotenoids, flavonoids, glycosides, lignans, phenolic compounds, terpenoids, saponins, steroids, and tannins are accountable for multifarious biological, ecological, pharmacological, and toxicological activities [ 3 , 8 , 9 , 11 , 18 , 19 ]. Most of these secondary metabolites have a role in the defence against environmental factors (e.g., pollution, drought, UV light, pathogens) [ 3 , 19 ] and can be found in plants either permanently or only at certain stages of their growth [ 20 ].…”

Secondary Metabolites: The Natural Remedies

“…In terms of animals' productivity, animals that ingest forages containing different plants secondary metabolites get their meat and dairy products enhanced in terms of biochemical richness making them good for human consumption [93].…”

Roles of citrus secondary metabolites in tree and fruit defence against pests and pathogens

“…Similarly, pyrethrins, azadirachtin and limonoids have strong insect deterrent ability and are commercially produced and used in agricultural systems (Clemensen et al, 2020). Besides the functions of these SM in plants in their natural environments, thanks to science, most of these SM are being induced in plants by external applications or used in industry to produce insecticides, herbicides, aromas, gums, cosmetics, flavour enhancers, etc.…”

“…Moreover, most of these SM has been used in the pharmaceutical industry due to their scientifically confirmed health benefits (Mendoza & Silva, 2018). Clemensen et al (2020) identify SM as agents responsible for communication among plants and their environment. They also reported that a better understanding of SM and their roles in agroecology would be beneficial for reducing the negative environmental impacts.…”