From the paddy fields of Asia to citrus orchards in Brazil, a group of global researchers has zeroed in on one of agriculture’s greatest adversaries: Xanthomonas, a bacterium capable of wreaking havoc on over 400 crop species.
In a study published in Science this December, a joint team from Southwest University and Jilin Agricultural University in the Chinese mainland, Duke University, the University of California and Seoul National University decoded how Xanthomonas secures essential nutrients from its hosts—revealing a crucial survival strategy that could reshape crop protection.
According to Wang Shanzhi, the paper’s first author, Xanthomonas oryzae injects a nutrient-synthesizing enzyme called AvrBs2 into rice cells. Inside, AvrBs2 taps into plant resources to create a cyclic sugar phosphate compound named xanthosan. The pathogen then reabsorbs xanthosan through a dedicated transport protein and breaks it down to fuel its growth.
"This synthesis-transport-utilization nutrient pipeline allows Xanthomonas to continuously plunder host resources," explains Wang. "Disrupting this pathway could significantly boost rice resistance to bacterial disease."
Building on these insights, the team devised an anti-xanthomonadin breeding strategy. By engineering rice varieties that block xanthosan uptake, researchers weakened the bacterium’s virulence. The transgenic plants showed stronger disease resistance without any negative impact on growth or metabolism.
Because AvrBs2 is found across many Xanthomonas strains, this approach also holds promise against other threats like citrus canker and tomato bacterial spot—marking a leap forward for sustainable agriculture and global food security.
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Chinese-international team unlocks new strategy against 'crop killer'
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