OsWRKY67 positively regulates blast and bacteria blight resistance by direct activation of PR genes in rice
Qing Liu1†, Xia Li2†,
Shijuan Yan3, Ting Yu3, Jianyuan Yang4,
Jingfang Dong1, Shaohong Zhang1, Junliang Zhao1,Tifeng
Yang1, Xingxue Mao1, Xiaoyuan Zhu4* and Bin Liu1*
BMC Plant Biology
Abstract
Background: WRKY
proteins are one of the largest gene families and are well-known for their
regulatory roles in many aspects of plant development, including plant response
to both biotic and abiotic stresses. Although the roles of WRKY proteins in leaf
blast resistance have been well-documented in rice, their functions in panicle
blast, the most destructive type of blast disease, are still largely unknown.
Results: Here,
we identified that the transcription of OsWRKY67 was strongly activated by leaf and panicle blast infection. OsWRKY67 is ubiquitously expressed and
sub-localized in the nucleus. Rice plants overexpressing OsWRKY67 showed quantitatively enhanced resistance to leaf blast,
panicle blast and bacterial blight. In contrast, silencing of OsWRKY67 increased the susceptibility
to blast and bacterial blight diseases. RNA-seq analysis indicated that OsWRKY67 induces the transcription of a
set of defense-related genes including the ones involved in the salicylic acid
(SA)-dependent pathway. Consistent with this, the OsWRKY67-overexpressing plants accumulated higher amounts of
endogenous SA, whereas lower endogenous SA levels were observed in OsWRKY67-silenced plants relative to
wild-type Nipponbare plants before and after pathogen attack. Moreover, we also
observed that OsWRKY67 directly binds
to the promoters of PR1a and PR10 to activate their expression.
Conclusions: These
results together suggest the positive role of OsWRKY67 in regulating rice
responses to leaf blast, panicle blast and bacterial blight disease.
Furthermore, conferring resistance to two major diseases makes it a good target
of molecular breeding for crop improvement in rice.
Keywords: OsWRKY67, Leaf blast, Panicle blast,
Bacterial blight, Salicylic acid Background：Cadmium (Cd) accumulation in rice followed
by transfer to the food chain causes severe health problems in humans. Breeding
of low Cd accumulation varieties is one of the most economical ways to solve
the problem. However, information on the identity of rice germplasm with low Cd
accumulation is limited, particularly in indica, and the genetic basis of Cd
accumulation in rice is not well understood.
