A novel maize-infecting mastrevirus from La Réunion Island

Abstract

Despite extensive sampling, only one virus belonging to the genus Mastrevirus of the family Geminiviridae, maize streak virus (MSV), has until now been detected in maize with maize streak disease (MSD) symptoms. Here, we report for the first time a second, highly divergent, mastrevirus isolated from two maize plants displaying characteristic MSD-like symptoms, sampled on the South-west Indian Ocean Island, La Re´union. The two isolates shared \57 % genome-wide identity with all other known mastreviruses. We propose calling the new species Maize streak Re´union virus. The genus Mastrevirus of the family Geminiviridae contains species with circular single-stranded DNA (ssDNA) genomes of approximately 2.7 kb. Mastreviruses infect a wide variety of monocotyledonous and dicotyledonous hosts and are transmitted by leafhopper vectors. Monocotinfecting mastreviruses have previously been found throughout Africa (including the South-west Indian Ocean islands: SWIO), Europe, Japan, Southeast Asia, the island of Vanuatu, and Australia. Mastreviruses previously found on SWIO islands such as La Re´union and Mauritius include various maize streak virus (MSV) strains, sugarcane streak Re´union virus (SSRV) and sugarcane streak virus (SSV) [13, 19, 25, 26]. Here, we report the genome sequences of two isolates (PR50 and PR52) belonging to a divergent mastrevirus species from La Re´union. Leaves were sampled in Saint Pierre (21.6161 S, 55.45784 E and 21.3206 S, 55.48536 E) from two maize plants displaying chlorotic streaks along leaf veins similar to those seen in MSV infections of maize.