Enhanced resistance to late blight pathogen conferred by expression of rice oxalate oxidase 4 gene in transgenic potato

Abstract

Phytophthora infestans is the pathogen responsible for late blight disease of potato. Multiple spraying of crop protection chemicals is so far the only means to control the disease. Despite the continuous effort from breeders, late blight resistant potato varieties are not available to farmers. In this context, development of genetic resistance by incorporating new genes through genetic engineering is an attractive way to combat the pathogen. Here, we report the development of transgenic potato cultivars overexpressing the rice oxalate oxidase 4 gene (Osoxo4). Transgenic lines showed higher activity of oxalate oxidase enzyme and were able to degrade externally applied oxalic acid. The levels of reactive oxygen H 2 O 2 were elevated in transgenic plants. The transcription of defense related genes (anionic peroxidase and phenylalanine ammonia lyase) was found to be elevated after pathogen inoculation. Detached leaf bioassays with spore suspension and in vitro plantlet bioassays with mycelia of P. infestans showed enhanced resistance in transgenic plants. Interestingly, constitutive overexpression of Osoxo4 did not show any effect on the morphology and yield of transgenic potato plants as evident from agronomic performance studies. Thus, constitutive expression of Osoxo4 represents an efficient strategy for engineering late blight resistance in potato.

GENETIC APPROACHES FOR ENGINEERING BIOTIC STRESS RESISTANCE IN POTATO (Solanum tuberosum L.)

“…Ameliorated resistance against the late blight disease was reported in the transgenic lines. The genes responsible for plant defense (phenylalanine ammonia lyase and anionic peroxidase) were found to be highly transcribed after the inoculation of the pathogen (Ghosh et al, 2016) (Table-2).…”

Understanding Invasive Plant Mycoparasites and Their Remedy Through Advanced Molecular Approaches

“…Over-expression of Osoxo4 (rice oxalate oxidase 4) gene in potato resulted in enhanced activity of oxalate oxidase enzyme thus with increased ability to degrade externally applied oxalic acid. After infection, the infectious fungal pathogens increased the levels of reactive oxygen species (H2O2) and defense related genes (anionic peroxidase and phenylalanine ammonia lyase) (Ghosh et al, 2016). Transgenic approach was used to develop sheath blight resistant varieties of rice.…”

“…Sheath blight in rice may be controlled by the overexpression of two defense-related genes OsCHI11 and OsOxO4. OsCHI11 encodes for chitinase whereas OsOxO4 encodes for oxalate oxidase (Karmakar et al, 2016). Chitinase plays important role in degradation of chitin and hydrolyzes cell wall of pathogenic fungi (Muthukrishnan et al 2001).…”

Application of Genetic Engineering in Plant Breeding for Biotic Stress Resistance

“…The development of genetic resistance by incorporating new genes through genetic engineering is an attractive way to combat the pathogen 'Phytophthora infestans' causing late blight disease of potato. The development of transgenic potato cultivars over expressing the rice oxalate oxidase 4 genes (Osoxo4) was developed (Ghosh et al, 2016). Detached leaf bioassays with spore suspension and in vitro plantlet bioassays with mycelia of P. infestans showed enhanced resistance in transgenic plants.…”

“…Interestingly, constitutive over expression of Osoxo4 did not show any effect on the morphology and yield of transgenic potato plants as evident from agronomic performance studies. The constitutive expression of Osoxo4 represents an efficient strategy for engineering late blight resistance in potato (Ghosh et al, 2016). Traditional breeding programmes have not been able to achieve long standing resistance, mainly because of the remarkable capacity of P. infestans to adapt rapidly to resistant plants (Haverkort et al, 2008).…”