Mosaic in Senna occidentalis in southern Brazil induced by a new strain of Soybean mosaic virus

Abstract

Plants of Senna occidentalis (sin. Cassia occidentalis) with mosaic symptoms were collected near a soybean (Glycine max) field where some plants exhibited symptoms of mosaic and blistering. A preliminary examination of leaf tissue from diseased S. occidentalis by electron microscopy revealed the presence of pinwheel inclusions as well as long flexuous particles, indicating the presence of a potyvirus. Host range, serology, and amino acid sequence from this potyvirus were similar to those from other Brazilian isolates of Soybean mosaic virus (SMV). The 3'- terminal region of the genomic RNA was cloned and a cDNA sequence of 1.9 kb upstream of the poly (A) tract was determined. The sequence contains a single open reading frame and a 3'- non-translated region (NTR) of 259 bp. The nucleotide sequence of the CP gene of SMV-Soc was 98% identical to that of Brazilian isolates SMV-B, SMV-L, and SMV-FT10. The percentage of nucleotide identity of their 3'-NTR's was 91, 98, and 99% in relation to SMV-L, SMV-B, and SMV-FT10, respectively. In contrast to other Brazilian SMV isolates studied, SMV-Soc was able to infect sunflower (Helianthus annuus). Based on these results, the S. occidentalis isolate was identified as a new strain of SMV belonging to the SMV strain, group G5 and was named SMV-Soc. This is the first report of naturaly occurring SMV infecting plants of S. occidentalis in Brazil, adding this weed as a new source of SMV in the field.

Identification of New Alleles for Resistance to Soybean Mosaic Virus in Soybean

“…Soybean mosaic virus has been listed as one of the most important diseases in China since 1994. In Brazil, epidemics of SMV have caused lower yields or discarded mottled seeds (Almeida et al, 2002). Furthermore, severe necrosis caused by SMV occurred as a serious problem in the 1970s, causing substantial yield losses in large production areas in Korea (Cho et al, 1977).…”

Two TGA Transcription Factor Members from Hyper-Susceptible Soybean Exhibiting Significant Basal Resistance to Soybean mosaic virus

“…Thereinto, the cultivated soybean NN1138-2 is hyper-susceptible to 22 SMV strains identified in China [ 24 ]. Besides, N. benthamiana plants, as an ideal model plant for the investigation of plant–pathogen interaction was also systemically infected by some SMV isolates [ 28 , 29 , 30 ], which are helpful for studying the function of soybean endogenous genes to SMV stress.…”

Soybean mosaic virus: a successful potyvirus with a wide distribution but restricted natural host range

“…SMV can cause significant damage in soybean and is present worldwide. SMV has a very narrow host range and, apart from soybean, natural infection has been documented only in Passiflora spp., Pinellia ternata, Senna occidentalis and Vigna angularis (Almeida et al, 2002;Benscher et al, 1996;Chen et al, 2004;Sun et al, 2008;Yoon et al, 2017). The SMV determinants for host specificity have not been mapped; however, it appears that the helper-component proteinase (HC-Pro) does not play a major role .…”