Para-aminobenzoic acid synthase from mushroom Agaricus bisporus enhances UV-C tolerance in Arabidopsis by reducing oxidative DNA damage

Abstract

UV exposure is harmful to plants. Increasing resistance against UV light is thus of great importance to their growth. Para-Aminobenzoic acid (PABA) has major roles in many biological processes, involving nucleotide biosynthesis, DNA repair, and DNA methylation, which contributed to UV irradiation. However, no study reports the effect of PABA on UV tolerance, or details of the underlying molecular mechanisms are explored. Hence, the objective of the research is to study the protective effect of PABA on UV in Arabidopsis and explored the molecular mechanisms. We overexpressed PABA synthase gene (Pabs) from Mushroom Agaricus bisporus in Arabidopsis and observed reduced root growth and UV-C hyposensitivity exposed to 2500 J m −2 UV-C light. UV-C-induced DNA damage was significantly reduced and the expression of decreased DNA methylation 1 (DDM1) was remarkably higher in the Pabs lines, suggesting that overexpression of Pabs may protect against UV-induced DNA damage. In addition, overexpression of Pabs leads to an elevated reactive oxygen species production at root tips and enhanced catalase and superoxide dismutase activity, which may correlate with the enhanced UV tolerance of the Pabs overexpression lines. In summary, overexpression of Pabs from A. bisporus enhances UV-C tolerance of Arabidopsis, suggesting that Pabs takes an important part in defence against DNA damage.

Symbiont‐specific responses to environmental cues in a threesome lichen symbiosis

“…(Liang et al, 2014). Furthermore, the expression of PABA synthase in the cyanomorph indicates stress response, as this enzyme has been shown to improve tolerance to thermal stress in Agaricus bisporus (Lu et al, 2014) and to enhance UV‐C resistance in Arabidopsis thaliana (Hu et al, 2019). As cyanobacteria are more susceptible to heat stress (see below) as well as high light when hydrated than green algae (Gauslaa et al, 2012), the expression of PABA synthase could be a response of the lichenized fungus to environmental stress in which the mycobiont supports the photobiont in keeping the holobiont vital.…”

Current Advances in the Functional Genes of Edible and Medicinal Fungi: Research Techniques, Functional Analysis, and Prospects

“…Similarly, the blue light and its receptor white collar complex coding genes FfWc1 and FfWc2 in F. filiformis can regulate the role of morphogenesis [185]. In addition, Gf.BMR1 from G. frondosa contributes to fruiting body development and pigment accumulation [186], abl-D from L. edodes promotes the formation of brown film in mycelia [187], and Pabs from A. bisporus [188] enhances UV tolerance. These studies can provide references for light control in the production of edible and medicinal fungi in factories.…”

Symbiont-specific responses to environmental cues in a threesome lichen symbiosis

“…(Liang et al, 2014). Furthermore, the expression of PABA synthase in the cyanomorph indicates stress response, as this enzyme has been shown to improve tolerance to thermal stress in Agaricus bisporus (Lu et al, 2014) and to enhance UV-C resistance in Arabidopsis thaliana (Hu et al, 2019). As cyanobacteria are more susceptible to heat stress (see below) as well as high light when hydrated than green algae (Gauslaa et al, 2012), the expression of PABA synthase could be a response of the lichenized fungus to environmental stress in which the mycobiont supports the photobiont in keeping the holobiont vital.…”