RNAseq Analysis of Endornavirus-Infected vs. Endornavirus-Free Common Bean (Phaseolus vulgaris) Cultivar Black Turtle Soup

Common bean (Phaseolus vulgaris L.) is the most important grain legume for direct human consumption worldwide and represents a rich source of protein, vitamins, minerals, and fiber (Broughton et al., 2003). The recent sequencing of the common bean genome, together with the availability of genomic and transcriptomic data have provided useful information to common bean breeders that will help in the development of genotypes with desirable characteristics (Schmutz et al., 2014; Vlasova et al., 2016). Endornaviruses are persistent viruses with a non-encapsidated RNA genome that ranges from 9.8 to 17.6 kb, infect plants, fungi, and oomycetes, are transmitted only via gametes, and do not cause apparent symptoms (Stielow et al., 2011; Fukuhara and Gibbs, 2012). Although endornaviruses have been reported in several economically important plant species, little is known about the effect they have on their hosts. One of the major obstacles to study their effect to the host is the lack of a transmission method. In plants, endornaviruses do not move from cell to cell and spread only during cell division. Recently, Khankhum et al. (2015) reported that most common bean genotypes ofMesoamerican origin are double-infected with Phaseolus vulgaris endornavirus 1 (PvEV1) and Phaseolus endornavirus 2 (PvEV2); in contrast, genotypes of Andean origin are often endornavirus-free. Black Turtle Soup (BTS), a cultivar of Mesoamerican origin has been reported to be double-infected by these two endornaviruses (Okada et al., 2013). A BTS endornavirus-free selection (BTS−), obtained from an endornavirus-infected BTS (BTS+) seed lot has been reported by Okada et al. (2013). To establish the bases for future research on the role that endornaviruses play in the common bean plant, and the effect these viruses have on the host gene expression, we conducted RNAseq on two BTS lines: one endornavirus-infected and the other endornavirus-free.