Expression Comparison of Phenylalanine Ammonia-lyase Gene in Scab Resistant and Susceptible Wheat Cultivars in response to Fusarium graminearum infection

Head blight of wheat, caused by Fusarium graminearum is one of the important disease that affecting wheat worldwide. Phenylalanine ammonia-lyase (PAL) is a key enzyme of the phenyl propanoid pathway has a crucial role in plant responses to biotic stress by production of ligninin, phenyl propanoid and salicylic acid .Hence, in the present study we compared  the time-course gene expression of phenylalanine ammonia lyase between FHB-resistance ʼSumai3ʻ wheat and susceptible ʼFalatʻ. Two wheat cultivars were planted in field at Gorgan agricultural research station, inoculated by F. graminareum suspension at anthesis. Total RNA was extracted from infected spikes sampled at 3,6,12,24,48,72 and 96 hours after inoculation. Quantitative Real-time PCR analysis showed no measurable increase in PAL gene expression in susceptible cultivar (Falat) up to 24 hours after inoculation and a slight increase observed at 48, 72 and 96 hours after inoculation. Whereas PAL expression in the resistant cultivar ( Sumai3)  was showed significant increased at 3 hours after inoculation. According to this, it seemed that earlier, faster and more up-regulation of PAL gene in resistant than susceptible cultivar can play an important role in wheat resistance to FHB.