Physiological Function of Phenolic Compounds in Plant Defense System

Abstract

Plants respond to various abiotic and biotic stress conditions through accumulation of phenolic compounds. The specificity of these phenolic compounds accumulation depends on the type of stress condition and the response of plant species. Light stress induces biosynthesis of phenolic acids and flavonoids in plants. Temperature stress initially induces biosynthesis of osmoprotective compounds and then later stimulates synthesis of antioxidant enzymes and antioxidant compounds such as flavonoids, tannins and phenolic acids in plant cells. Salinity causes oxidative stress in plants by inducing production of reactive oxygen species. To resist against oxidative stress plants produce polyphenols, flavonoids, anthocyanins, phenolic acids and phenolic terpenes. Plants biosynthesize phenols and flavonoids during heavy metal stress.to scavenge the harmful reactive oxygen species and to detoxify the hydrogen peroxide. Plants accumulate phenols at the infection sites to slow down the growth of microbial pathogens and restrict them at infected site. Plants also accumulates salicylic acid and H2O2 at the infection site to induce the systemic acquired resistance (SAR) against microbial pathogens. Plants accumulate phenolic compounds which act as inhibitor or toxicant to harmful nematodes, insects and herbivores. Hence, phenols regulate crucial physiological functions in plants to resist against different stress conditions.

Changes in Metabolic Profile of Rice Leaves Induced by Humic Acids

“…Cytosine and methylcytosine were also found in high concentrations in plants treated with HA and are determinant building segments for cellular code and essential for cell growth and proliferation. Finally, phenolic compounds help to regulate various physiological functions in plants during growth and development and are also involved in plant defense mechanisms [ 31 ]. The biosynthesis and accumulation of phenolic compounds during stress are regulated by phenylalanine ammonia-lyase (PAL) activity.…”

Patterns of Posidonia oceanica (L.) Delile tannin cells and leaf characteristics according to environmental conditions

“…The El Djamila site is characterized by the presence of the green algae C. cylindracea, which is likely to cause additional stress linked to interspecific competition with P. oceanica and contribute to an increase in the synthesis of tannin cells (Dumay et al, 2004;Pergent et al, 2008). Biosynthesis of phenolics would allow plants to better adapt to hostile environments (Lattanzio, 2013;Chowdhary et al, 2021) as phenolics are involved in the plants' strategy to overcome abiotic and biotic environmental stressors and avoid cell and tissue damage (Yeshi et al, 2022). Under stress, the diversity of phenolic compounds increases in P. oceanica to protect the plant from reactive oxygen species (ROS) that can be generated by anthropogenic pressures and/ or interspecific competition (Castellanno et al, 2012).…”

Changes of Several Metabolic Parameters of Soya Inoculated With Phytopathogens at Application Nanochelates

“…Non-enzymatic antioxidants such as phenolic compounds are known to protect plants from phytopathogens due their antimicrobial properties and other important functions: involved in growth and development, including hormone production, osmoregulation, UV protection, etc. (Wallis & Galarneau, 2020;Chowdhary et al, 2021). Plants are accumulated phenols to delay the growth of microbial pathogens and limit their spread in the infected area (Chowdhary et al, 2021).…”

“…(Wallis & Galarneau, 2020;Chowdhary et al, 2021). Plants are accumulated phenols to delay the growth of microbial pathogens and limit their spread in the infected area (Chowdhary et al, 2021). Research by Maddox et al (2010) indicated inhibition of the growth of gram-negative phytopathogenic bacteria, which causes diseases of many crops -Xylella fastidiosa, under the action of minimal inhibitory concentrations of 12 phenolic compounds.…”

“…At the same time there is an accumulation of salicylic acid and H 2 O 2 at the site of infection to regulate systemic acquired resistance (SAR) in plants. The multistage process of the plant protection mechanism against phytopathogens includes host cell death, necrosis, accumulation of phenolic compounds, cell wall modification, and synthesis of specific antimicrobial compounds (Chowdhary et al, 2021).…”