The Blast Resistance Gene Pi54of Cloned from Oryza officinalis Interacts with Avr-Pi54 through Its Novel Non-LRR Domains

Abstract

The dominant rice blast resistance gene Pi54 cloned by map-based cloning approach from indica rice cultivar Tetep confers broad spectrum resistance to Magnaporthe oryzae. In this investigation, an orthologue of Pi54 designated as Pi54of was cloned from Oryza officinalis conferring high degree of resistance to M. oryzae and is functionally validated. We have also characterized the Pi54of protein and demonstrate its interaction with AVR-Pi54 protein. The Pi54of encoded ∼43 kDa small and unique cytoplasmic LRR family of disease resistance protein having unique Zinc finger domain overlapped with the leucine rich repeat regions. Pi54of showed Magnaporthe-induced expression. The phylogenetic and western blot analysis confirmed orthologous nature of Pi54 and Pi54of genes, whereas the identity of protein was confirmed through MALDI-TOF analysis. The in silico analysis showed that Pi54of is structurally more stable than other cloned Pi54 proteins. The molecular docking revealed that Pi54of protein interacts with AVR-Pi54 through novel non-LRR domains such as STI1 and RhoGEF. The STI1 and GEF domains which interact with AVR-Pi54 are also components of rice defensome complex. The Pi54of protein showed differential domain specificity while interacting with the AVR protein. Functional complementation revealed that Pi54of transferred in two rice lines belonging to indica and japonica background imparts enhanced resistance against three highly virulent strains of M. oryzae. In this study, for the first time, we demonstrated that a rice blast resistance gene Pi54of cloned from wild species of rice provides high degree of resistance to M. oryzae and might display different molecular mechanism involved in AVRPi54-Pi54of interaction.

Effect of Botanicals for Management of Leaf Blast and Enhancing Yield Traits in Rice

“…It causes high yield loss about 30% globally [4], and thus major threat to global food security [5]. In India, rice blast is a major production constraint in irrigated ecosystem [6] and under severe epiphytic conditions may result a loss of 70-90% [7]. In central India the blast diseases cause significant loss in yield in traditional as well as improved varieties.…”

Genetic analysis of durable resistance to Magnaporthe oryzae in the rice accession Gigante Vercelli identified two blast resistance loci

“…Moreover, the expression of several Pi genes was observed to be modulated by the blast infection but no evidences are available about a role of the responsiveness on the resistant phenotype. Examples of R genes belonging to this class include Pi5-1 (Lee et al 2009), Pikm1-TS (Ashikawa et al 2008), Pi54 (Rai et al 2011), the Pi54 allele of O. officinalis (Pi54of; Devanna et al 2014) and Pi37 (Lin et al 2007). Considering the 22 blast resistance genes up to now cloned, at least 10 are not constitutively expressed; thus, in addition to sequence variations of resistance gene sequences, which represent the major causal difference between resistant and susceptible phenotypes (Meyers et al 2005;Luo et al 2012), the exploitation of the transcriptional modulation in R genes can provide complementary avenues for the identification of candidates for R gene functions.…”

Identification of the blast resistance gene Picl(t) from Chaling common wild rice (Oryza rufipogon Griff.)

“…Pid3‐A4 , an ortholog of Pid3 , was isolated from the common wild rice A4 ( Oryza rufipogon ; Lv et al, 2013). Pi54rh and Pi54of , which were cloned from Oryza rhizomatis and Oryza officinalis , respectively, are two orthologs of Pi54 (Das et al, 2012; Devanna, Vijayan, & Sharma, 2014).…”

“…and Pi54of, which were cloned from Oryza rhizomatis and Oryza officinalis, respectively, are two orthologs of Pi54 (Das et al, 2012;Devanna, Vijayan, & Sharma, 2014).…”