Construction and characterization of the infectious cDNA clone of the prevalent Chinese soybean mosaic virus strain SC3

Abstract

The resistance of different soybean varieties to the Chinese isolate of soybean mosaic virus SC3 was systematically studied. However, the resistance of different germplasm sources is still poorly understood. We constructed an infectious DNA clone of Chinese SMV isolate SC3 (pSC3) and modified it to allow the expression of yellow fluorescence protein (YFP)/ red fluorescence protein (RFP) during viral infection. By using the infection of pSC3-RFP, we can classify the resistance of different soybean cultivars to SMV-SC3 to the extreme resistance that restricts initial viral replication and the resistance that allows viral replication in the initially inoculated cells but restricts further movement. Also, we tracked the SMV-SC3 infection in susceptible cultivar Nannong 1138-2 (NN1138-2) and found that the seed transmission of SMV to the offspring plants can be tracked and recorded by imaging the virus-driven expression of YFP. Overall, we reveal new aspects of soybean resistance to SMV-SC3 and provide an essential tool to study the infection and transmission of SMV-SC3, which will help decipher the genes involved in SMV pathogenesis and host resistance.

Seed-Borne and Seed-Transmitted Viral Diseases and Their Effect on Yield of Different Soybean Genotypes

“…It was found that most SMV isolates do not have the ability to move from seed to plant, the percentage of transmission for them is 0%. Similar results about low per cent of SMV transmission to the leaves of newborn seedlings were demonstrated by Liu and co-authors in China (Liu et al, 2022) comparing to the previous studies which indicated seed transmission of the isolate SMV-SC3 as 0% to 13.68% in various domestic soybean cultivars (Song et al, 2015). Liu et al have showed that isolate SMV-SC3 is replicated in the seed coat (brown spot rate was about 44.98%) and had infected the hypocotyl and cotyledon with rate of 1.67% (n=539) of the seeds in the embryo (Liu et al, 2022).…”

“…Similar results about low per cent of SMV transmission to the leaves of newborn seedlings were demonstrated by Liu and co-authors in China (Liu et al, 2022) comparing to the previous studies which indicated seed transmission of the isolate SMV-SC3 as 0% to 13.68% in various domestic soybean cultivars (Song et al, 2015). Liu et al have showed that isolate SMV-SC3 is replicated in the seed coat (brown spot rate was about 44.98%) and had infected the hypocotyl and cotyledon with rate of 1.67% (n=539) of the seeds in the embryo (Liu et al, 2022). It is shown that 5 SMV isolates circulating in Ukraine are transmitted from seed to plant; the percentage of seed transmission for them is 1.9% -10.5% depending on the genotype of soybean plants and the properties of the virus isolate.…”