Investigation of response of tomatoes carrying mi-1.2 gene to avirulent and mi-1 virulent isolates of meloidogyne incognita

Tomato is one of the most important vegetables grown in the world. Root-knot nematodes cause yield losses in tomatoes. Mi-1.2 gene in tomato provides resistance to Meloidogyne incognita, M. javanica and M. arenaria species. However, virulent root-knot nematode populations can overcome this gene. In this study, the expression of the Mi-1.2 gene was investigated to avirulent G7 and virulent V6 isolates of M. incognita under controlled conditions using Real Time PCR (qPCR). Resistant tomato seedlings were separately inoculated with avirulent G7 and virulent V6 isolates of M. incognita. The plants were harvested at 48, 96 and 192 hours after inoculation. Total RNA was isolated from plant root systems of each biological replicate and cDNA was synthesized. Real time PCR was conducted with two SYBR Green I primers and two TaqMan probes. All reactions were performed in three technical replicates in one biological replicate and ΔCT, ΔΔCT, 2 –ΔΔCT and fold change values were calculated. Results showed the expression levels of plants inoculated with avirulent and virulent isolates could change according to primer sets and time period. RNA sequencing (RNA-seq) can be used to measure accurate expression levels of Mi-1.2 gene between samples in further studies.