Researchers from University of California at Riverside study the role of
microRNA (miRNA) in the resistance of tomato against Fusarium oxysporum that
causes vascular wilt disease. The experiment was conducted by doing a
comparative miRNA profiling between Moneymaker, a susceptible tomato
cultivar, and Motelle, a resistant tomato cultivar. The roots were treated
with water and F. oxysporum.
Two miRNA, slmiR482f and slmiR5300, which repress upon infection of F.
oxysporum were identified in Motelle. These two miRNAs were predicted to
have four targets and the virus-induced gene splicing (VIGS) system revealed
that these targets has the ability to encode a protein from a nucleotide
binding (NB) domain, which is associated with the plant's resistance.
However, among the targets predicted, none of them was observed which
corresponds to l-2, a resistance gene for F. oxysporum in
and further proves the necessity for this gene in increasing tomato's
immunity in F. oxysporum.