ARWV Common Disease in Woody Plants Now Largely Eliminated from Apple Trees, New Study Reveals

The University of Manchester researchers recently discovered that apple trees respond to a common viral infection by targeting a gene in the same track that genetic researchers aim at.

The discovery, as specified in a Phys.org report, exhibits that the fruit trees, which develop rubbery branches when infected, reflect how researchers attempt to modify trees genetically.

Apple rubbery wood virus or ARWV, causing apply rubbery wood disease, is now hugely, if not completely, eliminated from commercial apple trees.

Nonetheless, an extensive survey in the United Kingdom during the 1950s, when ARWV was widespread that in ascertain cases, more than 50 percent of apple trees sampled was infected with the said virus. The virus's widespread presence globally is well documented.

Woody Plant Materials

Although the trees' branches turn more flexible, no negative impacts on humans who have eaten the fruit from the infected trees have been documented, and there have been no adverse environmental consequences.

The study published in the journal, Current Biology offers an essential insight into how researchers might one day be able to process woody plant tissue so that it effectively produces sugars needed for biofuels.

Essentially, woody plant material represents an extensive renewable resource that has the potential to generate biofuels, as well as other chemicals with more favorable emissions of net carbon dioxide.

Nonetheless, researchers have not yet worked out an effective way to release its significant store of sugars, estimated to be at roughly 70 percent.

Next-Generation Sequencing Used

The research team demonstrated that the symptoms of ARWV infections occur from a decrease in lignin. This complex organic polymer forms key structural material that supports the tissues of the majority of plants.

Next-generation sequencing or NGS to examine the expression of all the genes in the rubbery apple tree branches, the team found that phenylalanine ammonia lyase or PAL, an enzyme accountable for lignin biosynthesis, was concealed by the plant in response to the infection.

The response to ARWV infection leads to the plant producing multiple tiny interfering RNAs, called vasiRNAs. The vasiRNAs are then targeting several of the plant's own genes to be downregulated or degraded, in what is believed to be part of the antiviral defense response.

One of the genes that the plant downregulated is PAL, which results in the reduction in lignin biosynthesis that provides the increased flexibility of the branches and facilitates the release of sugars.

ARWV-Infected Trees

Such a mechanism used by the apple rubbery wood virus to change lignin resembles how researchers have been changing lignin in genetically modified trees to make it a more straightforward process. Despite the modified lignin, the trees can manage to grow normally.

Since the disease has existed worldwide for many decades, even conservative approximations suggest that thousands of infected apple trees were reproduced.

As indicated in a similar Techtelegraph report, millions of apples from ARWV-infected trees were eaten without identified adverse health or environmental impacts despite the siRNA-induced lignin changes caused by the plant's response to the virus.

The researchers said, at present, the biofuel industry is using large areas of agricultural land to produce corn starch used to produce 60 liters of bioethanol.

Related information about woody plants is shown on Texas Brigades' YouTube video below:

Check out more news and information on Trees in Science Times.