Open AccessDevelopment of disease‐resistant rice by pathogen‐responsive expression of WRKY45
Author(s) -
Goto Shingo,
SasakuraShimoda Fuyuko,
Yamazaki Muneo,
Hayashi Nagao,
Suetsugu Mai,
Ochiai Hirokazu,
Takatsuji Hiroshi
Publication year - 2016
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.12481
Subject(s) - biology , xanthomonas oryzae , plant disease resistance , promoter , untranslated region , magnaporthe , pathogen , genetics , gene , oryza sativa , gene expression , messenger rna , magnaporthe grisea
Summary WRKY 45 is an important transcription factor in the salicylic acid signalling pathway in rice that mediates chemical‐induced resistance against multiple pathogens. Its constitutive overexpression confers extremely strong resistance against Magnaporthe oryzae and Xanthomonas oryzae pv. oryzae to rice, but has adverse effects on agronomic traits. Here, a new strategy to confer rice with strong disease resistance without any negative effects on agronomic traits was established by expressing WRKY 45 under the control of pathogen‐responsive promoters in combination with a translational enhancer derived from a 5′‐untranslated region ( UTR ) of rice alcohol dehydrogenase ( ADH ). Rice promoters that responded to M. oryzae and X. oryzae pv. oryzae infections within 24 h were identified, and 2‐kb upstream sequences from nine of them were isolated, fused to WRKY 45 cDNA with or without the ADH 5′‐ UTR , and introduced into rice. Although pathogen‐responsive promoters alone failed to confer effective disease resistance, the use of the ADH 5′‐ UTR in combination with them, in particular the PR 1b and GST promoters, enhanced disease resistance. Field trials showed that overall, PR 1b promoter‐driven (with ADH 5′‐ UTR ) lines performed the best and one had agronomic traits comparable to control untransformed rice. Thus, expressing WRKY 45 under the control of the PR 1b promoter with the ADH 5′‐ UTR is an excellent strategy to develop disease‐resistant rice, and the line established could serve as a mother line for breeding disease‐resistant rice.