Tobacco Ringspot Virus (TRSV) Blight Causing Pathogen Harms Bee Population

[Debby Bruck]

WIKIMEDIA, JON SULLIVAN The US  Department of Agriculture researchers identified tobacco ringspot virus (TRSV), a blight-causing pathogen that wreaks havoc on soy crops, in a routine screen of commercial honeybees, according to a study published today (January 21) in mBio. The virus appeared to infect nearly every tissue of its bee hosts, excluding the eyes, and to spread between the insects via mites that feed on bee hemolymph.

• Agriculture goals directed toward genetic modification of the soybean to resist this virus. Bud blight, caused by Tobacco ringspot virus (TRSV; Genus: Nepovirus; Family: Comoviridae), can significantly reduce the seed yield and seed quality of soybean [Glycine max (L.) Merr.]. The identification of resistance genes and the development of resistant cultivars constitute an effective strategy for preventing yield loss.

Identifying the cause of honeybee population declines has become a top priority, as the insects are critical to the multibillion dollar agricultural industry. RNA viruses like TRSV are particularly concerning because of their high mutation rates and ability to subvert the host’s immune response. “Because of their genetic diversity, we see a lot of host jumping,” lead author Yan Ping Chen, a bee pathologist at the USDA Agricultural Research Service laboratory in Maryland, told the Los Angeles Times. How frequently the bees are picking up the virus from plants, as opposed to passing it among themselves, and whether the bees are spreading the virus to otherwise healthy plants, remains to be seen.

• Tomato and Tobacco Ringspot Virus Decline | Tomato and tobacco ringspot virus decline is caused by two closely related viruses: Tomato Ringspot Virus (TomRSV) and Tobacco Ringspot Virus (TRSV) respectively. Based on symptoms these two viruses cannot be separated. In the year infection occurs, mosaic and leaf chlorosis is usually evident. More severe symptoms are pronounced in the second year. The vines are generally weaker and buds die more readily from freezing winter temperatures. Smaller leaves, shorter internodes, and reduced yield are typical symptoms for these two viruses. In the third year the vine is significantly stunted but may survive for more than three years with no yield.  The control of TomRSV and TRSV is mainly by using virus-free material but resistant varieties and rootstocks may be utilized. Large numbers of plant species can host these viruses, therefore weed infestation should be reduced. 
  
  
  • Fruit clusters are sparse with uneven ripening
  • Leaves exhibit a random pattern of yellows and greens or leaf yellowing in first year of infection
  • Smaller leaves, shorter internodes, and reduced yield are evident in second year
  • Growth is severely stunted in the third year

The virus’s direct role in bee declines is also unclear at this point, though the authors point out in their paper that “the increasing prevalence of TRSV in conjunction with other bee viruses from spring toward winter in infected colonies was associated with gradual decline of host populations and winter colony collapse, suggesting the negative impact of the virus on colony survival.”

“I’d be hesitant to proclaim that this virus is the cause of colony collapse, but it certainly shows the degree of our lack of understanding of the complexity of bee pathogen interactions,” Randy Oliver, a biologist and beekeeper who was not involved in the study, told the LA Times.

Insects as vectors. Aphids

Can we take into account time of vulnerability for the soybean plants to be infected with the virus?

What about considering area where the disease is commonly found?  North Central states.

Could we characterize this disease as INTENSE or having a particularly pace? TRSV, bud-blight of soybeans is one of the the most severe.

What about adding the season or time of development? Would we say this is puberty? Most significant yield loss occurs when plants become infected before flowering. 

 

Can someone repertorize to find some remedies?

• Tobacco Ringspot Virus Signs and Symptoms

• Primarily seed borne at a low level in the field

• Resulting in scattered infected plants

• Maturity delays so they remain green until killed by frost

• Pods underdeveloped, tops of plants have shortened internodes

• Leaves distorted

  • Source

 

Maybe add to the repertorization the symptoms displayed by the bees?

• Tobacco Ringspot Virus Signs and Symptoms

[david hartley]

the proposed "solution" = GMO ?!

when will they EVER learn  ...