Catch-22 in specialized metabolism: balancing defense and growth

Abstract

Plants are unsurpassed biochemists that synthesize a plethora of molecules in response to everchanging environment. The majority of these molecules considered as specialized metabolites, effectively protect the plant against pathogens and herbivores. However, this defense most likely comes at a high expense, leading to reduction of growth (known as the ‘growth-defense tradeoff’). Plants employ several strategies to reduce the high metabolic costs associated with chemical defense. Production of specialized metabolites is tightly regulated by a network of transcription factors facilitating its fine-tuning in time and space. Multifunctionality of specialized metabolites, their effective recycling system by re-using carbon, nitrogen and sulphur, thus, re-introducing them back to the primary metabolite pool allows further cost reduction. Spatial separation of biosynthetic enzymes and their substrates, sequestration of potentially toxic substances and conversion to less toxic metabolite forms are plant’s solutions to avoid the detrimental effects of metabolites they produce as well as reduce production costs. Constant fitness pressure from herbivores, pathogens and abiotic stressors lead to honing of specialized metabolite biosynthesis reactions to be timely, efficient and metabolic cost-effective. In this review we assess the costs of specialized metabolites production for chemical defense and the different plant mechanisms to reduce the price of of such metabolic activity in terms of self-toxicity and growth.

The Laccase Gene Family Mediate Multi-Perspective Trade-Offs during Tea Plant (Camellia sinensis) Development and Defense Processes

“…In this study, herbivore attack enhanced the expression of most CsLACs in subclades IV, V and VI, but suppressed most genes in subclades I, II and III, which exhibited an opposite expression pattern. These results seems to obey the law that plants suffer limited resource reallocation to facilitate the prioritization of defense towards growth to survive during herbivore attack [4,45], and may account for the incompatibility between growth and defense programmes, known as the "growth-defense trade-off" phenomenon established upon plant-herbivore interactions [5,[46][47][48][49][50]. Altogether, our findings provide one CsLACsbased explanation for the growth-defense trade-off in tea plant at the molecular level.…”

Terpenoid indole alkaloid biosynthesis in Catharanthus roseus: effects and prospects of environmental factors in metabolic engineering

“…The plant specialized metabolites are defense molecules that confer resistance against pathogens and herbivores (Panda et al 2021 ). Similarly, C. roseus produces TIAs in response to herbivore and pathogens as chemical defense (Fig.…”

Gliotoxin, an Immunosuppressive Fungal Metabolite, Primes Plant Immunity: Evidence from Trichoderma virens -Tomato Interaction

“…Tomato plants primed by T. atroviride , for example, displayed stronger direct defense against an aphid pest, as well as produced volatiles that attracted a parasitoid wasp ( 11 ). In plant immunity, there is often a tradeoff between growth and defense responses ( 12 , 13 ), though some strains of Trichoderma can simultaneously prime plant immunity and promote growth ( 14 , 15 ). Plant roots apparently detect the fungus, at first, as an invader.…”