Lr34 has two extremely valuable characteristics. Whereas one gene usually only protects against a single disease for a limited time under commercial production, Lr34 provides long lasting disease resistance and acts against multiple diseases.
“The fungi that cause rust diseases are very adaptable and can rapidly evolve to overcome resistant cereal varieties,” Dr Lagudah says. “Scientists and farmers can commonly only respond to a rust outbreak after it has passed, but tests conducted after identifying the Lr34 gene sequence show it has provided partial but constant protection against leaf rust for over 80 years.”
Understanding the molecular nature of this type of resistance has important implications for long-term control of rust diseases.
CSIRO Plant Industry’s Dr Wolfgang Spielmeyer says an immediate application is the use of the gene sequence to directly select and breed wheat plants that carry the resistance against multiple pathogens.
“The Lr34 gene can now be combined with other disease resistance genes into single cultivars faster and with greater confidence providing even more durable resistance,” he says.