Secret weapon of smart bacteria tracked to 'sweet tooth'

Texas A&M AgriLife Research’s Dr. Libo Shan, left, along with doctoral student Kevin Cox have figured out how a once-defeated bacterium has re-emerged to infect cotton in a battle in which could sour much of the Texas along with US crop. along with the idea boils down to in which: A smart bacteria that has a sweet tooth. Credit: Texas A&M AgriLife Research photo by Kathleen Phillips

Researchers have figured out how a once-defeated bacterium has re-emerged to infect cotton in a battle in which could sour much of the Texas along with U.S. crop.


along with the idea boils down to in which: A smart bacteria that has a sweet tooth.

“the idea’s a food fight between the bacterium along with the cotton plant,” said Dr. Libo Shan, Texas A&M AgriLife Research plant pathologist in College Station. “The bacterium tricks the host to produce food for itself. yet once the bacterium will be inside plant, the idea saves its own resources along with switches the plant’s transportation of sugar to itself. The host plant will be deprived of sugar needed for energy, can’t get rid of the bacteria along with the disease progresses. in which bacterium will be very smart.”

The discovery will be inside May 24 edition of the journal Nature Communications.

The disease will be bacterial blight caused by Xanthomonas citri subspecies malvacearum, otherwise known as Xcm. Decades ago, the idea wiped out thousands of cotton acres annually, showing up first as brown spots on leaves, stems along with even bolls then spreading until a plant – indeed entire fields of plants – dropped leaves along with stopped growing. the idea’s equally devastating on rice along with cassava, Shan said.

Scientists long ago identified Xcm as the culprit yet didn’t know how or why the bacterium went on its warpath. Meanwhile, plant breeders tested types of cotton in which were less susceptible along with developed varieties in which were more resistant to the disease. in which worked through the late 20th Century until about six years ago when Xcm bacterial blight again showed up in force on the cotton crop in Texas along with various other states, wasting even varieties in which previously could ward the idea off.

AgriLife Research scientists in Lubbock began searching the fields along with plants for answers to help farmers cope, while another team in College Station took a deep look at the bacterium along with cotton interaction at the cellular level along with discovered its covert operations.

“in which bacteria causes disease in cotton by using a secret weapon, a sort of needle-like structure, to inject the protein effectors into cotton cells,” Shan said. “One of these effectors mimics the host transcription factors, directly targeting along with activating the host gene transcription of a plant sugar transporter. The plant then begins to pump energizing sugar through within the cell to the apoplast or pathway of the cell, thus feeding the bacteria.”

The discovery was made in part by Kevin Cox, a Texas A&M doctoral student through St. Louis, Missouri, who has been working with Shan for nearly four years along with will be lead author on the paper.

“My part of the idea was basically to identify what gene was being activated by a particular effector through the bacteria in order to cause disease,” he said. “When we found out what the target of in which effector was, in which’s when we got excited. in which was pretty cool.”

Shan said the excitement reverberated among researchers for several reasons.

“First the idea will provide a mechanistic understanding of how the bacterium causes disease in cotton, along with second the idea provides a potential strategy for control of in which cotton disease along with resistance against the bacteria,” she said. “Third, the idea may provide potential tools to do earlier diagnostic for the presence of in which disease before symptoms show inside field.”

in which’s important, Shan said, because once a farmer sees the disease inside field, the idea’s too late.

“the idea will be very hard to control. Up to 40 percent of cotton yield can be affected,” she added. “So though in which will be a fundamental discovery of in which mechanism how the bacterium causes disease, the idea provides a lot of potential for field application.”

Shan said isolates of the early strain along with current strain of the Xcm bacterium—along with the sequencing of their genomes—indicated there are polymorphisms genetically slightly different yet acting the same in their attack on cotton.

“We compared the genetic differences in trying to pin down a reason for the disease’s rampant reemergence in recent years,” she said. “the idea will be likely in which rapid evolvement of completely new bacterial effectors contributed to the resurgence of in which disease.”

The team will continue to explore bacterial blight in cotton, as well as study the implications of these finds on rice along with cassava.

“We want to implement the tools for cotton diagnostics by working with engineers to develop a very sensitive probe, perhaps like a doctor would certainly use for diagnosing diabetes in humans,” Shan said. “the idea would certainly be useful to have a probe able to detect sugar content inside field for cotton, particularly inside early seedling stage.”

She said the team may also explore “gene editing technologies” to take out the portion of the gene in which allows the bacteria to take the plant’s food, which would certainly make the cotton more resistant.


Explore further:
Researchers crack genetic code determining leaf shape in cotton

More information:
Nature Communications, DOI: 10.1038/NCOMMS15588

Journal reference:
Nature Communications

Provided by:
Texas A&M University

Secret weapon of smart bacteria tracked to 'sweet tooth'

Leave a Reply

Your email address will not be published. Required fields are marked *