Strategies to Modulate Specialized Metabolism in Mediterranean Crops: From Molecular Aspects to Field

Abstract

Plant specialized metabolites (SMs) play an important role in the interaction with the environment and are part of the plant defense response. These natural products are volatile, semi-volatile and non-volatile compounds produced from common building blocks deriving from primary metabolic pathways and rapidly evolved to allow a better adaptation of plants to environmental cues. Specialized metabolites include terpenes, flavonoids, alkaloids, glucosinolates, tannins, resins, etc. that can be used as phytochemicals, food additives, flavoring agents and pharmaceutical compounds. This review will be focused on Mediterranean crop plants as a source of SMs, with a special attention on the strategies that can be used to modulate their production, including abiotic stresses, interaction with beneficial soil microorganisms and novel genetic approaches.

Keywords: advanced breeding; arbuscular mycorrhizal fungi; biotechnological approaches; cell bio-factory; elicitation; glandular trichomes; omics; plant growth-promoting bacteria; secondary metabolites; stress response; transcriptional networks.

Figure 1

Scheme representing the diverse factors (natural, on the left, and artificial, on the right part) that can modulate specialized metabolites in plants: abiotic stresses as drought, salt, UV radiation and temperature; microorganisms (i.e., biotic factors) such as plant growth-promoting bacteria—PGPB and arbuscular mycorrhizal fungi—AMF; in vitro systems; advanced breeding techniques based on trans/cis-genesis, genome editing and -omics approaches.