Gene Details:

Functional Descriptions:

  • We have reported previously that a transcription factor identified in rice, WRKY45 (OsWRKY45), plays a pivotal role in BTH-induced disease resistance by mediating SA signalling.
  • OsWRKY45 alleles play different roles in abscisic acid signalling and salt stress tolerance but similar roles in drought and cold tolerance in rice.
  • Together, these results indicate that the OsWRKY45 may be involved in the signal pathways of both biotic and abiotic stress response.
  • Over-expression of the stress-induced OsWRKY45 enhances disease resistance and drought tolerance in Arabidopsis.
  • Here it is shown that the alleles OsWRKY45-1 and OsWRKY45-2 play different roles in abscisic acid (ABA) signalling and salt stress adaptation in rice.
  • OsWRKY45-1 transgenic plants showed no obvious difference from negative controls in response to salt stress.
  • In contrast, OsWRKY45-2-overexpressing lines showed increased ABA sensitivity and reduced salt stress tolerance, and OsWRKY45-2-suppressing lines showed reduced ABA sensitivity and increased salt stress tolerance.
  • These results suggest that OsWRKY45-1 negatively and OsWRKY45-2 positively regulates ABA signalling and, in addition, OsWRKY45-2 but not OsWRKY45-1 negatively regulates rice response to salt stress.
  • OsWRKY45-1-overexpressing lines showed reduced ABA sensitivity, whereas OsWRKY45-1-knockout lines showed increased ABA sensitivity.
  • OsWRKY45-1-regulated Xoo resistance was accompanied by increased accumulation of salicylic acid and jasmonic acid and induced expression of a subset of defense-responsive genes, while OsWRKY45-2-regulated Xoo resistance was accompanied by increased accumulation of jasmonic acid but not salicylic acid and induced expression of another subset of defense-responsive genes.
  • OsWRKY45-1 and OsWRKY45-2 transgenic plants showed differential expression of a set of ABA- and abiotic stress-responsive genes, but they showed similar responses to cold and drought stresses.
  • The relationship between OsWRKY45 expression and ABA signalling is discussed.
  • OsWRKY45-1-overexpressing plants showed increased susceptibility and OsWRKY45-1-knockout plants showed enhanced resistance to Xoo and Xoc.
  • In contrast, OsWRKY45-2-overexpressing plants showed enhanced resistance and OsWRKY45-2-suppressing plants showed increased susceptibility to Xoo and Xoc.
  • Interestingly, excessive WRKY45 expression rendered rice plants sensitive to low temperature and salinity, and stress sensitivity was correlated with the induction of defence genes by these stresses.
  • Previously, we reported that rice transformants overexpressing WRKY45 driven by the maize ubiquitin promoter were strongly resistant to both pathogens; however, their growth and yield were negatively affected because of the trade-off between the two conflicting traits.
  • Comparisons among different transformant lines showed that, overall, the strength of WRKY45 expression was positively correlated with disease resistance and negatively correlated with agronomic traits.
  • The agronomic traits of two lines expressing WRKY45 driven by the OsUbi7 promoter (PO sUbi7 lines) were nearly comparable to those of untransformed rice, and both lines were pathogen resistant.
  • The rice transcription factor WRKY45 plays a central role in the salicylic acid signalling pathway and mediates chemical-induced resistance to multiple pathogens, including Magnaporthe oryzae and Xanthomonas oryzae pv.
  • WRKY45 is an important transcription factor in the salicylic acid signalling pathway in rice that mediates chemical-induced resistance against multiple pathogens.
  • Here, a new strategy to confer rice with strong disease resistance without any negative effects on agronomic traits was established by expressing WRKY45 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).
  • Thus, expressing WRKY45 under the control of the PR1b 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.
  • The activation of WRKY45 by benzothiadiazole (BTH) was reduced under low temperature and high salinity, probably through abscisic acid (ABA) signalling.
  • Phosphorylation of WRKY45, the central transcription factor in salicylic-acid (SA)-signalling-dependent pathogen defence in rice, via the OsMKK10-2-OsMPK6 cascade, was required to fully activate WRKY45.
  • An ABA treatment dephosphorylated/inactivated OsMPK6 via protein tyrosine phosphatases, OsPTP1/2, leading to the impaired activation of WRKY45 and a reduction in Magnaporthe oryzae resistance, even after BTH treatment.
  • Here we show that a TE-siRNA, TE-siR815, causes opposite functions for the two alleles, WRKY45-1 and WRKY45-2, of the WRKY45 transcription factor in rice resistance to Xanthomonas oryzae pv.
  • These results suggest that TE-siR815 contributes to the natural variation of the WRKY45 locus and TE-siR815-induced suppression of ST1 results in the negative role of WRKY45-1 but positive role of WRKY45-2 in regulating disease resistance.
  • The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens.
  • 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.
  • The antisense expression of OsWRKY45 (as-wrky) enhanced BPH-induced levels of ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs.
  • Mutation of WRKY45 compromises the enhanced blast resistance and bacterial leaf blight resistance conferred by arf8 mutant.

Literature:

Gene Resources:

Sequences:

cDNA Sequence
  • >LOC_Os05g25770.1
    GCTGCTTTGAGCTCCATCACCAGCTGAGCTGCGAGGAAGAGAGAGTGCGAGAGTGCGCGGCAGCGGCAGTGTAGTGTCAGTCACTGGGTGTGCGCTTGCTTGCTTGGATTGAGGATGACGTCATCGATGTCGCCGGCGCCGGCGCCGGCGTACGCGCAGGTGATGGAGGACATGGAGAAGGGGAAGGAGCTGGCGGCGCAGCTGCAGGGGCTCCTCCGCGACTCGCCGGAGGCCGGCCGCTTCGTCGACCAGATTCTCCACACCTTCTCCCGGGCGATGCGGGCGCTCGACAAGGCGGCGGTCTCCGCCGCCGGAGGAGAAGGGTCGGAGGTGCAGAGCGAGGTCACCTGCGGGGGCGGGGCCAGCGCCGGCGGGAAGAGGAAAGCCCCCGCCGCCGACCGGAAGGCCAACTGCCGCAGGAGGACGCAGCAATCGTCCGGGAATTCGGTGGTCGTCAAGAACCTCGACGACGGCCAGGCATGGCGCAAGTACGGGCAGAAGGAGATCCAAAACTCCAAGCACCCAAAGGCCTACTTCCGGTGCACGCACAAGTACGACCAGCTGTGCACGGCGCAGCGGCAGGTGCAGCGCTGCGACGACGACCCGGCGAGCTACAGGGTCACCTACATCGGCGAGCACACCTGCCGGGACCCGGCCACCGCCCCCATCATCGCGGCGCACGTCATCCACCAGGTCGCCGCCGGCGACAACGACGACGGCTGCGGCGGCCTCCAAGCGGGGTCCCGCCTCATCAGCTTCGTCGCCGCGCCGGCGGCGCCAGTAGACGCTGCCGCGGCGCCGACGACCAGCACGATCACCACGGTCACCGCGCCGGGCCCGCTGCTGCAGCCGCTCAAGGTGGAGGGCGGCGTCGGCTCGTCCGACCAGGAGGAGGTGCTGAGCAGCCTCACGCCCGGCAGCTCCGCGGCGCGCGGCGGCGGCGGCGGCGGCGGAGTCGCGGGTCCCTTCGGGCCGGACCAGGGCGATGTCACGTCCTCCCTGCACTGGAGCTACGACGCCGTCGCCGGCATGGAGTTCTTCAAGAACGACGAGGTTGTCTTCGATCTGGACGACATTATGGGTTTGAGCTTTTGATCACCGAAGAATCATGGATGGACACGGGCCGGGTAAAACGATCGAAAGAAGATGGATTCCACGCGTGTGTACAGAAATAATTAGCGGCAGCGCGGATCTTAATTTGGAACTTGCAAAGATACTCCTAATTAGCCTGGCTAGATTAGTTTGTAAATTCCTTGTTGATGTGTCGTCTCAGCTTTAAGCTGCAGACATGCTAGCAAGTAACAACACGATTAGTACGTAGTAATGTGGTTCTTGATTATGAGCTGGGGGTCTTAACCTTTTTTGTGTGACAAGCAAGAGAAGAGGATTTGGGTACAATGTAATCCTGTTCTTCCGCTTTCGAAAAAAAAAAACATATAGCTTCACGTGCCTAATCCTCTGCTAAATGTTGTGCCATAACTGTAGAAAGATTCGCCATTTGGCTACGACTTTACTGTACATGCCGTTC
CDS Sequence
  • >LOC_Os05g25770.1
    ATGACGTCATCGATGTCGCCGGCGCCGGCGCCGGCGTACGCGCAGGTGATGGAGGACATGGAGAAGGGGAAGGAGCTGGCGGCGCAGCTGCAGGGGCTCCTCCGCGACTCGCCGGAGGCCGGCCGCTTCGTCGACCAGATTCTCCACACCTTCTCCCGGGCGATGCGGGCGCTCGACAAGGCGGCGGTCTCCGCCGCCGGAGGAGAAGGGTCGGAGGTGCAGAGCGAGGTCACCTGCGGGGGCGGGGCCAGCGCCGGCGGGAAGAGGAAAGCCCCCGCCGCCGACCGGAAGGCCAACTGCCGCAGGAGGACGCAGCAATCGTCCGGGAATTCGGTGGTCGTCAAGAACCTCGACGACGGCCAGGCATGGCGCAAGTACGGGCAGAAGGAGATCCAAAACTCCAAGCACCCAAAGGCCTACTTCCGGTGCACGCACAAGTACGACCAGCTGTGCACGGCGCAGCGGCAGGTGCAGCGCTGCGACGACGACCCGGCGAGCTACAGGGTCACCTACATCGGCGAGCACACCTGCCGGGACCCGGCCACCGCCCCCATCATCGCGGCGCACGTCATCCACCAGGTCGCCGCCGGCGACAACGACGACGGCTGCGGCGGCCTCCAAGCGGGGTCCCGCCTCATCAGCTTCGTCGCCGCGCCGGCGGCGCCAGTAGACGCTGCCGCGGCGCCGACGACCAGCACGATCACCACGGTCACCGCGCCGGGCCCGCTGCTGCAGCCGCTCAAGGTGGAGGGCGGCGTCGGCTCGTCCGACCAGGAGGAGGTGCTGAGCAGCCTCACGCCCGGCAGCTCCGCGGCGCGCGGCGGCGGCGGCGGCGGCGGAGTCGCGGGTCCCTTCGGGCCGGACCAGGGCGATGTCACGTCCTCCCTGCACTGGAGCTACGACGCCGTCGCCGGCATGGAGTTCTTCAAGAACGACGAGGTTGTCTTCGATCTGGACGACATTATGGGTTTGAGCTTTTGA
Protein Sequence
  • >LOC_Os05g25770.1
    MTSSMSPAPAPAYAQVMEDMEKGKELAAQLQGLLRDSPEAGRFVDQILHTFSRAMRALDKAAVSAAGGEGSEVQSEVTCGGGASAGGKRKAPAADRKANCRRRTQQSSGNSVVVKNLDDGQAWRKYGQKEIQNSKHPKAYFRCTHKYDQLCTAQRQVQRCDDDPASYRVTYIGEHTCRDPATAPIIAAHVIHQVAAGDNDDGCGGLQAGSRLISFVAAPAAPVDAAAAPTTSTITTVTAPGPLLQPLKVEGGVGSSDQEEVLSSLTPGSSAARGGGGGGGVAGPFGPDQGDVTSSLHWSYDAVAGMEFFKNDEVVFDLDDIMGLSF*