Enhancement of Sclerotina sclerotiorum and Oxalic Acid Resistance in Tobacco by a Novel Pathogen‐Induced GST Gene from Sunflower

Abstract

The glutathione S‐transferase (GST) gene resists stress‐induced toxins and is widely expressed in eukaryotes. The role of a novel GST gene (HaGSTp1) in disease resistance in sunflower (Helianthus annuus L.) was investigated using the transcriptome library data of Sclerotina sclerotiorum (Lib.) de Bary‐infected sunflower cultivar ‘LSK‐2’ and cloned. The full length of HaGSTp1 is 639 bp. It encodes 212 amino acids, has a molecular weight of 52.4 kDa, has an isoelectric point of 5.16, and is classified into the Phi class of the GST gene. The GSH binding site (G site) and substrate‐specific binding site (H site) are located at the N and C terminal domains, respectively. The tissue expression pattern demonstrated that the HaGSTp1 gene is mainly expressed in leaf tissues of sunflower and is induced by S. sclerotiorum, oxalic acid, salicylic acid, abscisic acid, and hydrogen peroxide. Transformation of the HaGSTp1 gene into tobacco (Nicotiana tabacum L.) increased the activity of GST and glutathione peroxidase by approximately twofold. All these data indicated potential enhancement of plant disease resistance potency by the HaGSTp1 gene.

Selenium Promotes Sunflower Resistance to Sclerotinia Sclerotiorum by Regulating Redox Homeostasis and Hormonal Signaling Pathways

“…For example, the activities of POD, SOD, and NOX were differentially regulated while CAT activity showed unchanged during the infection course of S. sclerotiorum in oilseed rape (Liang et al 2009). The activities of APX and GPx were also regulated in common bean and tobacco challenged by S. sclerotiorum (Fagundes-Nacarath et al 2018;Ma et al 2018). Therefore, ROS modulation of host plants plays critical roles in plant defense responses to S. sclerotiorum infection (Ranjan et al 2018).…”