Molecular characterization of emaraviruses associated with Pigeonpea sterility mosaic disease

Abstract

Sterility Mosaic Disease (SMD) of pigeonpea (Cajanus cajan (L.) Millspaugh) is a complex disease due to various factors including the presence of a mixed infection. Comparison of dsRNA profile and small RNA (sRNA) deep sequencing analysis of samples from three locations revealed the presence of Pigeonpea sterility mosaic virus-I and II (PPSMV-I and II) from Chevella and only PPSMV-II from Bengaluru and Coimbatore. PPSMV-I genome consisted of four while PPSMV-II encompassed six RNAs. The two viruses have modest sequence homology between their corresponding RNA 1–4 encoding RdRp, glycoprotein precursor, nucleocapsid and movement proteins and the corresponding orthologs of other emaraviruses. However, PPSMV-II is more related to Fig mosaic virus (FMV) than to PPSMV-I. ELISA based detection methodology was standardized to identify these two viruses, uniquely. Mite inoculation of sub-isolate Chevella sometimes resulted in few- to- many pigeonpea plants containing PPSMV-I alone. The study shows that (i) the N-terminal region of RdRp (SRD-1) of both the viruses contain “cap-snatching” endonuclease domain and a 13 AA cap binding site at the C-terminal, essential for viral cap-dependent transcription similar to the members of Bunyaviridae family and (ii) P4 is the movement protein and may belong to ‘30 K superfamily’ of MPs.

The population structure of Rose rosette virus in the USA

“…The highest level of variability was observed in RNA 5 (5 %). Similar findings have also been observed in pigeon pea sterility mosaic virus-2 isolates, with 5 % variability seen in the RNA 5 segment [54]. In addition, diversity in RNA 3 and RNA 4 was similar to that previously observed for RRV and other emaraviruses [55][56][57][58][59][60][61].…”

High Plains wheat mosaic virus: An enigmatic disease of wheat and corn causing the High Plains disease

“…In contrast, a few emaraviruses were mechanically transmitted through crude sap: RLBV and Actinidia chlorotic ring spot‐associated virus onto Nicotiana benthamiana (McGavin et al, 2012 ; Zheng et al, 2017 ), PPSMV‐1 and PPSMV‐2 onto N . benthamiana and Nicotiana clevelandii (Kumar et al, 2017 ; Patil & Kumar, 2015 ), TiRSaV onto N . benthamiana and N .…”

“…through crude sap: RLBV and Actinidia chlorotic ring spot-associated virus onto Nicotiana benthamiana(McGavin et al, 2012;Zheng et al, 2017), PPSMV-1 and PPSMV-2 onto N. benthamiana and Nicotiana clevelandii(Kumar et al, 2017;Patil & Kumar, 2015), TiRSaV onto N. benthamiana and N. tabacum(Olmedo-Velarde et al, 2019), and rose rosette virus (RRV) onto rose plants(Verchot et al, 2020).…”

A diagnostic marker kit for Fusarium wilt and sterility mosaic diseases resistance in pigeonpea

“…Like FW, SMD is also a complex disease since the causal agent, i.e. pigeonpea sterility mosaic virus (PPSMV), has several variants in different pigeonpea growing zones (Kumar et al 2017;Reddy et al 1993). Therefore, primary panel of genotypes was selected to represent maximum pigeonpea growing zones with known resistant and susceptible genotypes.…”