BnGSTU12 enhance the Sclerotinia sclerotiorum resistance in B. napus
through ROS homeostasis and JA signaling pathway
Abstract
Sclerotinia sclerotiorum was one of the serious diseases in
B. napus, which could result in large loss of the yield of
B. napus. In previous study, we identified the candidate GST
gene, BnGSTU12, associated with sclerotiorum stem
resistance and the expression levels of BnGSTU12 in resistant
lines were higher than that in susceptible lines. We analyzed the
function of BnGSU12 in B. napus in this study. The
expression level of BnGSTU12 increased significantly at 24 h
after S. sclerotiorum infection. Transgenic functional analysis
indicated that overexpression of BnGSTU12 in A. thaliana
and B. napus and transient expression of BnGSTU12 in
tobacco enhanced S. sclerotiorum resistance, whereas
virus-induced gene silencing (VIGS)-mediated BnGSTU12 silencing
reduced S. sclerotiorum resistance. The inoculated
BnGSTU12-OE A. thaliana and B. napus plants showed
higher antioxidant enzyme activity and lower H 2O
2 content than WT. BnGSTU12 was rapidly induced
by the hormone SA and MeJA, and we investigated whether the JA and SA
pathway was involved in GSTU12 mediated S. sclerotiorum
resistance. JA content was higher in the inoculated BnGSTU12-OE
than WT plants. In addition, the expression level of JAR gene
involving in JA-Ile biosynthesis and JA-responsive genes (
PDF1.2) were higher, JAZ gene repressing JA signaling was
less in OE plants than WT after 12 and 24 h inoculation with S.
sclerotiorum. The results showed that BnGSTU12 enhanced S.
sclerotiorum resistance through ROS homeostasis and JA signaling
pathway.