Gene expression and antioxidant enzymatic activity in passion fruit exposed to aluminum

Abstract

The objective of this study was to investigate changes in enzymatic activity and gene expression related to antioxidant defense in two passion fruit cultivars (FB100 and FB200) exposed to aluminum. The specific activity of superoxide dismutase (SOD), catalase and ascorbate peroxidase were analyzed, in addition to their relative expression pattern. The characterization of gene expression was achieved by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) technique followed by densitometric analysis. Plants were irrigated every two days with a nutrient solution: pH 6; pH 4; 0.2 and 2.0 mM Al (pH 4). The leaves were collected at the times 0 h, 2 days, 5 days and 10 days. The analysis of the potential oxidative stress induced by aluminum demonstrated increased expression of catalase and superoxide dismutase gene, and only on the cultivar FB100 this increase was accompanied by an increase of SOD enzymatic activity, which indicates its higher efficiency on the removal of reactive oxygen species (ROS) compared to cultivar FB200.

Overexpression of the Aldehyde Dehydrogenase Gene ZmALDH Confers Aluminum Tolerance in Arabidopsis thaliana

“…Overexpression of ZmAT6 in both maize and Arabidopsis could partially enhance Al tolerance via scavenging ROS [ 46 ]. Additionally, enhancing the activity of antioxidases in antioxidant pathways also contributes to resistance to Al toxicity in plants [ 47 ]. In our study, ZmALDH enhanced the Al tolerance of Arabidopsis by promoting the synthesis of GSH and AsA, enhancing the enzymatic activity of GR and APX, and increasing the transcript level of AtGR1 ( Figure 8 , Figure 9 and Figure S5 ).…”

A Maize ZmAT6 Gene Confers Aluminum Tolerance via Reactive Oxygen Species Scavenging

“…Therefore, the ROS scavenging responses of antioxidant enzymes under Al stress conditions varied depending on the species and genotypes. Alternatively, the overexpression of genes encoding ROS-scavenging enzymes in several plant species had documented that their activities enhanced the tolerance of Al ( Panda et al., 2013 ; Sun et al., 2017 ; Irany et al., 2018 ). In this study, ZmAT6 enhanced the aluminum tolerance of maize by increasing the expression level of ZmSOD gene and improving the activity of the antioxidant enzymes SOD in the antioxidant enzymatic system.…”

“…In addition, a semi reduction of the superoxide radical ion caused by aluminum toxicity may lead to oxidative stress and serious cell damage. The enzyme-catalyzed antioxidant system and the non-enzymatic antioxidant system of plants could scavenge excessive ROS and reduce the cell damage caused by aluminum toxicity (Achary et al, 2008;Irany et al, 2018). The intensity of Evans blue staining and the content of MDA in the cells of target tissue could reflect the lipid peroxidation of the cell membrane.…”

“…To protect the plants from Al-triggered oxidative stress, they have evolved two defense ways, including enzyme-catalyzed antioxidant system and non-enzymatic system, to decrease ROS production, detoxify ROS, and stimulate the recovery from ROS-induced damages (Ahmad et al, 2010;Chowra et al, 2017;Daspute et al, 2017). The enzyme-catalyzed antioxidant system mainly improve the activity of antioxidant enzymes which include peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) (Ezaki et al, 2013), or increase the expression level of antioxidant enzyme genes (Irany et al, 2018). While the non-enzymatic antioxidants are ascorbate (AsA) and glutathione (GSH) (Xu et al, 2012).…”