Genome Sequencing of Potato Late Blight Pathogen, Phytophthora infestans, A2 Mating Type

Abstract

Phytopthora infestans is the most infamous pathogen of potato plant which causes huge economic loss worldwide. The causative agent is an oomycete which causes disastrous potato disease known as Late Blight or Potato Blight. In this study, we report 152 Mb of sequenced and assembled genome (out of the estimated 240 Mb genome size) of P. infestans HP-10-31 strain of A2 mating type, isolated in rainy season of the year 2010 from Shimla hills. In total we obtained 15,791,076 number of single end reads assembled into 47,871 contigs. We predicted 21,118 gene models, out of which 6.5% were found to be homologous with pathogenesis related genes of fungi, bacteria and oomycetes. In the present study 8,162 (38%) of predicted genes were functionally annotated. The genome of this pathogen is enriched with genes associated with binding catalytic, oxidoreductase and transferase. 713 protein coding genes were extracted as secretome and we further identified 35 RxLR proteins in whole sequenced genome. The study identified 405 CAZy homologues in P. infestans HP-10-31 genome. GH superfamily was the most highly characterized containing 210 homologues, distributed in 32 families.  CE, PL and GT superfamilies had each 56, 35 and 70 homologues tabulated in 10, 4 and 20 families respectively. The sequence information is the first study which covers the preliminary information on Indian strain of A2 mating type. It may prove helpful for understanding behavioral activity and designing of control strategies in Indian habitat.