Effects of target gene siRNA soaking in cereal cyst nematode, Heterodera avenae infecting wheat

Abstract

Heterodera avenae is an obligate sedentary endoparasite that causes significant crop losses in wheat, barley and oats. Functional genomics of H. avenae is required to identify and target the essential genes involved in their pathogenesis. Based on the available transcriptome, we have cloned and sequenced four genes (epn-1, pab-1, emb-4 and nhr-91) differentially expressed between pre-parasitic juveniles (J2s) and feeding females of H. avenae. Further, gene expression was evaluated in three developmental stages of H. avenae. It was noted that expression of nhr-91 and epn-1 was highest in the feeding females while that of pab-1 was in J2s. On the other hand, expression of emb-4 was highest in the egg stage. Microscopic observations revealed that siRNA soaking of epn-1, pab-1 and emb-4 in respective siRNA resulted in reduced nematode development by 71%, 60%, 26.5% and reproduction by 68%, 45% and 14.4%, respectively. The siRNA soaking of nhr-91 increased the nematode development by 25% while that of reproduction by 54%. Given the importance of these genes in the nematode life cycle, the findings are particularly noteworthy. Our study shows target genes epn-1 and pab-1, could serve as potential targets for effectively impairing nematode reproduction and further development when expressed via a host-induced gene silencing approach.