Resistance tests were conducted on the melanism mutant near Iso-genic linesc 514mln and the silkworm 514 by feeding their larvae with a suspension of BmNPV virus.The half-lethal concentration (LC50 )of the two strains was determined,along with the expression levels of genes involved in the melanin metabolic pathway (BmDDC,BmAANAT,BmEboy)and the silkworm resistance genes a-gainst BmNPV (Bmlipase-1,Bm-serine protease-2 ).Additionally,the changes in the content of dopa-mine and its precursor,L-DOPA,synthesized in the heads of the silkworm larvae were investigated to assess the resistance of the melanism mutant silkworm to BmNPV and to explore the underlying mechanisms.The results indicated that the LC50 of the fifth instar larvae of the melanism mutant silkworm 514mln was significantly higher compared to the silkworm 514 .Under non-infection condi-tions,the expression levels of Bmlipase-1 and Bm-serine protease-2 in the 514mln larvae were signifi-cantly greater than those in the 514 larvae.Under infection conditions,the expression levels of the aforementioned genes increased in both 514mln and 514 larvae,and the content of L-DOPA and dopa-mine in the heads of the larvae also showed significant increases.It is inferred that the melanism mu-tant silkworm (mln)may enhance its resistance to BmNPV by upregulating the expression of its inter-nal resistance genes.
维普
万方数据