Antifungal activity of a Pinus monticola antimicrobial peptide 1 (Pm-AMP1) and its accumulation in western white pine infected with Cronartium ribicola

2011 ◽  
Vol 57 (8) ◽  
pp. 667-679 ◽  
Author(s):  
Arezoo Zamany ◽  
Jun-Jun Liu ◽  
Abul Ekramoddoullah ◽  
Richard Sniezko

Pinus monticola antimicrobial peptide 1 (Pm-AMP1) was expressed and purified from bacterial cell lysate and its identity and purity confirmed by Western blot analysis using the Pm-AMP1 antibody. Application of Pm-AMP1 resulted in visible hyphal growth inhibition of Cronartium ribicola , Phellinus sulphurascens , Ophiostoma montium , and Ophiostoma clavigerum 3–12 days post-treatment. Pm-AMP1 also inhibited spore germination of several other phytopathogenic fungi by 32%–84% 5 days post-treatment. Microscopic examination of C. ribicola hyphae in contact with Pm-AMP1 showed distinct morphological changes. Seven western white pine ( Pinus monticola Douglas ex D. Don) families (Nos. 1, 2, 5, 6, 7, 8, 10) showing partial resistance to C. ribicola in the form of bark reaction (BR) were assessed by Western immunoblot for associations between Pm-AMP1 accumulation and family, phenotype, canker number, and virulence of C. ribicola. There was a significant difference (p < 0.001) in mean Pm-AMP1 protein accumulation between families, with higher levels detected in the full-sib BR families (Nos. 1, 2, 5) than the half-sib BR families (Nos. 6, 7). Family 8, previously described as a Mechanism ‘X’ BR family, had the highest number of BR seedlings and displayed high Pm-AMP1 levels, whereas the susceptible family (No. 10) showed the lowest levels (p < 0.05). Family 1 showed a significant association between Pm-AMP1 accumulation and overall seedling health (p < 0.01, R = 0.533), with higher protein levels observed in healthy versus severely infected seedlings. In general, low Pm-AMP1 levels were observed with an increase in the number of cankers per seedling (p < 0.05), and seedlings inoculated with the avirulent source of C. ribicola showed significantly higher Pm-AMP1 levels (p < 0.05) in the majority of BR families. Cis-acting regulatory elements, such as CCAAT binding factors, and an AG-motif binding protein were identified in the Pm-AMP1 promoter region. Multiple polymorphic sites were identified within the 5′ untranslated region and promoter regions. Our results suggest that Pm-AMP1 is involved in the western white pine defense response to fungal infection, as observed by its antifungal activity on C. ribicola and a range of phytopathogens as well as through its association with different indicators of resistance to C. ribicola.

2005 ◽  
Vol 95 (3) ◽  
pp. 284-291 ◽  
Author(s):  
Jun-Jun Liu ◽  
Abul K. M. Ekramoddoullah ◽  
Arezoo Zamani

In the present study, in a candidate gene approach, a class IV chitinase gene (PmCh4A) of pathogenesis-related family three was cloned and characterized in western white pine (Pinus monticola). PmCh4A chitinase expression in the different organs of healthy seedlings was below levels detectable by western immunoblot analysis using an antibody raised against PmCh4A protein. However, a 27-kDa isozyme of PmCh4A accu mulated in both susceptible and slow-canker-growth (SCG) resistant seedlings after infection by Cronartium ribicola. As with fungal infection, the application of a signal chemical (methyl jasmonate) and a protein phosphatase 1 and 2A inhibitor (okadaic acid) increased the PmCh4A protein accumulation. Furthermore, another 26-kDa isozyme was expressed specifically in SCG resistant seedlings, providing a potential tool for marker-assisted selection in forest breeding. Wounding treatment also induced expression of the protein. These data suggest that the class IV chitinase PmCh4A is involved in the defense response of western white pine to infection and abiotic stresses.


1980 ◽  
Vol 58 (5) ◽  
pp. 574-577 ◽  
Author(s):  
R. J. Hoff ◽  
G. I. McDonald

Low frequency of needle spots caused by the blister rust fungus (Cronartium ribicola J. C. Fisch. ex Rabenh.) in western white pine (Pinus monticola Dougl.) appears to be an expression of a horizontal resistance factor in secondary needles. Heritability averaged 37% for two sets of a 4 tester × 10 candidate mating system. We discuss the implications of these results with respect to developing varieties of western white pine resistant to blister rust.


1970 ◽  
Vol 48 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Raymond J. Hoff

In a study of the effects of preformed inhibitory compounds in resistant and susceptible western white pine (Pinus monticola Dough), ether fractions from 6 of 16 resistant trees substantially reduced germination of basidiospores of Cronartium ribicola J. C. Fisch. ex Rabenh. as compared to the percentage of germination observed in paired susceptible trees. The foliage of western white pine was found to contain a high level of other inhibitory compounds as well. The implications of these and other findings concerning toxic compounds are discussed.


Genome ◽  
2019 ◽  
Vol 62 (7) ◽  
pp. 477-488
Author(s):  
Jun-Jun Liu ◽  
Yu Xiang

Proteins with nucleotide-binding site (NBS) and leucine-rich repeats (LRRs) have been reported to play important roles in plant disease resistance, growth, and development. However, no comprehensive analysis of this protein family has been performed in conifers. Here we report that the Pinus monticola PmTNL2 gene is a member of the NBS-LRR superfamily. Quantitative reverse transcription-PCR (qRT-PCR) analysis revealed that the PmTNL2 transcript was expressed in a tissue-specific pattern with extensive regulation by various environmental stimuli in western white pine seedlings, suggesting its wide involvement in stress defense and diverse developmental processes. In silico analysis of the PmTNL2 promoter region revealed multiple cis-regulatory elements characterized with potential functions for development-, light-, and stress-regulated transcript expression. Expression patterns were largely confirmed by PmTNL2 promoter-directed reporter gene expression using stable transgenic Arabidopsis plants. Notably, the PmTNL2 promoter activity was highly expressed in shoot apical and floral meristems and was induced strongly with vascular specificity by pathogen infection. Our data has provided a fundamental insight into both expression regulation and putative functions of the PmTNL2 gene in the context of plant growth and development, as well as in responses to environmental stressors. Promoter application as a potential tool for tree improvement was further discussed.


1970 ◽  
Vol 48 (7) ◽  
pp. 1429-1430 ◽  
Author(s):  
A. E. Harvey ◽  
J. L. Grasham

Inoculations of western white pine seedling stems with rust-infected tissue cultures produced one successful rust infection after 5 months. The infection was typical of this rust (Cronartium ribicola J. C. Fisch. ex Rabenh.) and the presence of haustoria was confirmed. Infected cortex tissue from this seedling was used to reestablish the isolate on host tissues grown in vitro.


1970 ◽  
Vol 48 (1) ◽  
pp. 71-73 ◽  
Author(s):  
A. E. Harvey ◽  
J. L. Grasham

Rust mycelia from tissue cultures infected with Cronartium ribicola J. C. Fisch. ex Rabenh. were grown on cellophane membranes in the absence of physical contact with host tissue. These membranes were in contact with agar media containing imbedded, actively growing western white pine (Pinus monticola Dougl.) tissue cultures. Identities of these cultures were verified by reestablishing infections in healthy host tissue cultures.


1975 ◽  
Vol 53 (21) ◽  
pp. 2497-2505 ◽  
Author(s):  
G. I. McDonald ◽  
R. J. Hoff

Two kinds of needle spots, red and yellow, were found 9 months after artificial inoculation of 2-and 3-year-old, nursery-grown western white pine seedlings with field-run Cronartium ribicola inoculum. The causal agent was verified by histological examination of samples of the two spot types, by exclusion of inoculum from a portion of the seedlings, and by comparison of stem symptoms originating from the two spot types. When seedlings from three populations and two inoculation years were classed according to spot type, the class proportion varied from 68.4 to 9.0% yellow-type plants, 5.7 to 63.9% red-type plants, and 25.8 to 41.7% double-type plants. However, the mean spot frequency of each class for all three populations exhibited little variation. One population yielded frequencies of 12.11, 9.55, and 20.12 spots per metre of needle length on yellow-type, red-type, and double-type seedlings respectively. The second population yielded 7.66, 9.85, and 17.14; and the third, 7.00, 9.14, and 18.49. The existence of distinct seedling classes combined with evidence that the sum of the means of the two single-type classes (12.11 + 9.55 = 21.66) was nearly equal to the mean of the double-type class (20.12) led the authors to conclude that field-run inoculum was composed of at least two races and that the pine seedlings exhibited differential resistance to those races.


2001 ◽  
Vol 16 (4) ◽  
pp. 149-152 ◽  
Author(s):  
R.S. Hunt ◽  
G.D. Jensen

Abstract Seedlings from different western white pine (Pinus monticola) parent phenotypes were inoculated with blister rust (Cronartium ribicola) to determine how they compared to the British Columbia standard candidate phenotype (canker-free with all branches retained) in their ability to produce resistant seedlings. Comparisons were separated into two seed zones, coastal and interior, as well as pooled. The phenotypic categories were: (1) standard candidate, (2) standard candidate except lacking lower branches, (3) standard candidate except for bark reactions in the stem, (4) standard candidate except for stem bark reactions and closer than 100 m to a similar candidate (Texada phenotype), (5) standard candidate except for a tolerant reaction to a basal canker, (6) standard candidate except for a single canker high in the crown, (7) normally cankered trees, (8) USDA Forest Service selections for Dorena, OR, and (9) bulked forest run seedlots. Open-pollinated offspring from parents were inoculated each fall from 1987-1995, and infection spots were tallied the following spring. All seedling infection spot values were normalized to seedlings from a control tree, which were included in each inoculation. The progeny from bulk seedlots and the Texada phenotype were significantly more spotted than the other phenotypes. The least spotted families (top 1/6) were predominantly from the standard, cankered, and bark-reaction phenotypes. Resistance of individual seedlings was detected by annual inspection and recording slow-canker-growth responses up to 7 yr post-inoculation. None of the progeny from bulk seedlots or the control exhibited slow canker growth. There was no significant difference among the progeny of the other eight parental phenotypes in the incidence of slow-canker-growth resistance. Of these eight, only normally cankered candidates failed to have any families rank in the top one-sixth for the most slow-canker-growth resistance. However, since the sample size was small for normally cankered, high cankered, and tolerant phenotype, the results are considered preliminarily. Since we consider slow-canker-growth resistance to be most useful, we recommended that future selection programs for parents include relaxed rule bark reaction and no lower branch phenotypes. West. J. Appl. For. 16(4):149-152.


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