Gas chromatography mass spectrometry based metabolic profiling reveals biomarkers involved in rice-gall midge interactions

The Asian rice gall midge (Orseolia oryzae Wood-Mason) is a serious pest of rice that causes huge loss in yield. While feeding inside the susceptible host, maggots secrete substances that facilitate the formation of a hollow tube-like structure called gall and prevent panicle formation. The present investigation was carried out to get an account of biochemical changes occurring in the rice plant upon gall midge feeding. Metabolic profiling of host tissues from three rice varieties, namely, TN1, Kavya, and RP2068, exposed to gall midge biotype 1 (GMB1), was carried out using gas chromatography mass spectrometry (GC-MS). TN1 and GMB1 represented compatible interaction, while Kavya and GMB1 as well as RP2068 and GMB1 represented incompatible interactions. The current study identified several metabolites that could be grouped as resistance, susceptibility, infestation, and host features based on their relative abundance. These may be regarded as biomarkers for insect-plant interaction in general and rice-gall midge interaction in particular.