The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens

Jiayi Huangfu,Peng Kuai,Meng Ye,Jiancai Li,Ran Li,Tongfang Zhang,Yonggen Lou

doi:10.3390/ijms17060697

Jiayi Huangfu, Peng Kuai + Show 5 more

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https://doi.org/10.3390/ijms17060697

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Abstract

WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens) and by treatment with jasmonic acid (JA) or salicylic acid (SA). The antisense expression of OsWRKY45 (as-wrky) enhanced BPH-induced levels of H2O2 and ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs. Consistently, lower population densities of BPH on as-wrky lines, compared to those on wild-type (WT) plants, were observed in field experiments. On the other hand, as-wrky lines in the field had lower susceptibility to sheath blight (caused by Rhizoctonia solani) but higher susceptibility to rice blast (caused by Magnaporthe oryzae) than did WT plants. These findings suggest that OsWRKY45 plays important but contrasting roles in regulating the resistance of rice to pathogens and herbivores, and attention should be paid if OsWRKY45 is used to develop disease or herbivore-resistant rice.

Highlights

To protect themselves from attack by biotic stresses, such as pathogens and herbivores, plants have evolved constitutive and induced defenses [1,2,3]
DiscuIsnstihoins study, we investigated the role of OsWRKY45 in herbivore-induced defense responses in rIicnet.hBisy sctoumdyb,inwinegindvaetastifgroamtedmtohleecruollaerobfiOolsoWgyR, KreYv4e5rsiengheenrebtiicvso, rceh-ienmdiustcreydadnedfebnioseasrseasypso, nwsees in rice.foBuyncdomthbatinBiPnHg dinafteastfartoimonminodluecceudlatrhbeieoxlopgreys,srieovneorsf eOgseWnReKtiYcs4,5ch(Feimguirsetr1yaa).nMd obrieooavsesra,yssi,lewnceinfogund that brown planthopper (BPH) infestation induced the expression of OsWRKY45 (Figure 1a)
Silencing OsWRKY45 enhanced the levels of BPH-elicited ethylene and H2O2 but did not influence the production of jasmonic acid (JA) and salicylic acid (SA) (Figure 3); in the end, the resistance of rice to BPH increased (Figure 4)

Summary

Introduction

To protect themselves from attack by biotic stresses, such as pathogens and herbivores, plants have evolved constitutive and induced defenses [1,2,3]. Induced plant defense begins with the recognition of pathogen- or herbivore-associated signals, followed by the elicitation of a defense-related signaling network consisting mainly of jasmonic acid (JA)-, salicylic acid (SA)-, ethylene- and H2O2-mediated pathways and the up-regulation of transcript levels of defense-related genes and the production of defense compounds [4]. During this induction process, transcription factors (TF) perform a vital role [5,6,7,8]. While the roles of WRKYs in plant defense responses against biotic stresses are known, the underlying molecular mechanisms and the roles of different WRKYs in this process remain largely unclear

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