Microscopy and proteomic analysis of the non-host resistance of Oryza sativa to the wheat leaf rust fungus, Puccinia triticina f. sp. tritici

Abstract

Rice (Oryza sativa) cv. Nipponbare expresses non-host resistance (NHR) to the wheat leaf rust fungus, Puccinia triticina f. sp. tritici (Ptt). When the leaves of cv. Nipponbare were inoculated with Ptt, approx 93% of the urediniospores germinated on the leaf surface, but only 10% of the germinated spores formed appressoria over the stomata at one day post inoculation (1 dpi). Hydrogen peroxide (H(2)O(2)) accumulated in host cells around the appressoria at 3 dpi. Approx. 3% of the appressoria produced short hyphae inside the leaf, and fluorescence was observed in tissue invaded by the hyphae by 7 dpi. At 22 dpi, 0.2% of the sites with appressoria formed branching infection hypha in mesophyll cells, but no substomatal vesicles, haustorial mother cells or haustoria were observed. Proteins were extracted from leaves 3 dpi and analyzed by two-dimensional gel electrophoresis (2-DE). A total 33 spots were reproducibly up-regulated and 9 were down-regulated by infection compared to the water inoculated control. Of these, 30 were identified by MALDI-TOF Mass Spectrometry. The identified proteins participate in defense/stress responses, energy/carbohydrate metabolism, oxidation-reduction processes, protein folding/turnover/cleavage/degradation, signal transduction and cell death regulation. The results indicates that NHR of rice to Ptt is consistent with a shift in protein and energy metabolism, increased antimicrobial activities, possibly including phytoalexin accumulation and cell wall reinforcement, increased cell repair, antioxidive and detoxification reactions, and enhanced prevention of plant cell death. Nearly half of the up-regulated identified proteins were associated with chloroplast and mitochondrial physiology suggesting important roles for these organelles during NHR.

Characterization and Genetic Analysis of Rice Mutant crr1 Exhibiting Compromised Non-host Resistance to Puccinia striiformis f. sp. tritici (Pst)

“…As the model of monocotyledonous plant, rice is unusual in not being affected by a rust pathogen (Ayliffe et al, 2011b). Several studies indicated that rust fungi have some potential to infect rice and trigger host defense responses such as production of reactive oxygen species and accumulation of Pathogenesis-related proteins (Ayliffe et al, 2011a; Li et al, 2012). Thus, it is of interest to characterize non-host interaction between rice and cereal rust pathogens and identify key genes involved in NHR.…”

“…Thus, it is of interest to characterize non-host interaction between rice and cereal rust pathogens and identify key genes involved in NHR. Proteomic studies revealed proteins that are involved in phytoalexin production, and glycerol-3-phosphate metabolism may have a role in rice NHR to P. triticina and Pst (Li et al, 2012; Zhao et al, 2014). …”

Proteomics: A Successful Approach to Understand the Molecular Mechanism of Plant-Pathogen Interaction

“…A total of 33 protein spots were up-regulated and 9 were down-regulated by infection compared to the control, of which 30 were identified by MALDI-TOF-MS. The identified proteins were involved in defense/stress responses, energy/carbohydrate metabolism, oxidation-reduction processes, protein folding/turnover/cleavage/degradation, signal transduction and cell death regulation [96]. Proteomic analysis indicated that NHR of rice to Ptt is directly correlated with protein and energy metabolism, increased antimicrobial activities, possibly including phytoalexin accumulation and cell wall reinforcement, increased cell repair, antioxidative and detoxification reactions, and enhanced prevention of plant cell death [96].…”

“…The identified proteins were involved in defense/stress responses, energy/carbohydrate metabolism, oxidation-reduction processes, protein folding/turnover/cleavage/degradation, signal transduction and cell death regulation [96]. Proteomic analysis indicated that NHR of rice to Ptt is directly correlated with protein and energy metabolism, increased antimicrobial activities, possibly including phytoalexin accumulation and cell wall reinforcement, increased cell repair, antioxidative and detoxification reactions, and enhanced prevention of plant cell death [96]. Almost half of the up-regulated identified proteins were associated with chloroplast and mitochondrial physiology which suggests important roles for these organelles during NHR [96].…”

“…Proteomics studies play a key role in delineating the molecular mechanism of non-host resistance. Li et al, [96] studied the NHR of Oryza sativa cv. Nipponbare against the wheat leaf rust fungus, Puccinia triticina f. sp.…”