Overexpression of thionin genes in Arabidopsis and resistance to Heterodera schachtii

Thionins and Thionin-like peptides are small cysteine-reach antimicrobial plant peptides that play an important role in resistance to plant pathogens and have been isolated from several plant species. The purpose of this study is overexpression of Thionins-like (At۱g۱۲۶۶۵ and At۱g۲۰۶۱۸) genes for resistance to H. schachtii. At۱g۱۲۶۶۵ (ThiL۱۲) and At۱g۲۰۶۱۸ (ThiL۲۰) genes have isolated from Arabidopsis thaliana and transgenic plants were generated through Agrobacterium-mediated using the pMAA-red vector by the floral dips method. Expression of the thionin-like genes in overexpression lines were confirmed by RT-PCR and observation the red seeds and homozygous seeds of overexpression lines were planted and high overexpression of ThiL۱۲ and ThiL۲۰ peptides in plant indicated by quantitative RT-PCR. In order to investigate the resistance, Arabidopsis roots of ۱۲-day old seedling were inoculated under sterile conditions with about ۵۰-۶۰ juveniles per plant on Knop medium. ۱۵ days post infection, when females and males could be clearly distinguished, the number of males and females was counted and the results were compared with wild-type Arabidopsis (Col-۰). Also, the results of the overexpression lines showed significant enhanced resistant to H. schachtii as compared to wild type. However, the results demonstrate that there was no significant difference in resistance against H. schachtii in the size of syncytia and females in Arabidopsis roots with the exception of the line for At۱g۲۰۶۱۸ gene.

Keywords:

Arabidopsis , Resistance , Thionin-like , Sugar beet nematode