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Elevated CO2 influences nematode-induced defense responses of tomato genotypes differing in the JA pathway.

Sun Y, Yin J, Cao H, Li C, Kang L, Ge F - PLoS ONE (2011)

Bottom Line: In the current study, we tested the hypothesis that elevated CO(2) will favor the salicylic acid (SA)-pathway defense but repress the jasmonic acid (JA)-pathway defense of plants against plant-parasitic nematodes.Our results suggest that, in terms of defense genes, secondary metabolites, and volatile organic compounds, induced defense of nematode-infected plants could be affected by elevated CO(2), and that CO(2)-induced changes of plant resistance may lead to genotype-specific responses of plants to nematodes under elevated CO(2).The changes in resistance against nematodes, however, were small relative to those reported for chewing insects.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Integrated Management of Pest and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.

ABSTRACT
Rising atmospheric CO(2) concentrations can affect the induced defense of plants against chewing herbivores but little is known about whether elevated CO(2) can change the induced defense of plants against parasitic nematodes. This study examined the interactions between the root-knot nematode Meloidogyne incognita and three isogenic tomato (Lycopersicon esculentum) genotypes grown under ambient (390 ppm) and elevated (750 ppm) CO(2) in growth chambers. In a previous study with open-top chambers in the field, we reported that elevated CO(2) increased the number of nematode-induced root galls in a JA-defense-dominated genotype but not in a wild-type or JA-defense-recessive genotype. In the current study, we tested the hypothesis that elevated CO(2) will favor the salicylic acid (SA)-pathway defense but repress the jasmonic acid (JA)-pathway defense of plants against plant-parasitic nematodes. Our data showed that elevated CO(2) reduced the JA-pathway defense against M. incognita in the wild-type and in a genotype in which defense is dominated by the JA pathway (a JA-defense-dominated genotype) but up-regulated the SA-pathway defense in the wild type and in a JA-defense-recessive genotype (jasmonate-deficient mutant). Our results suggest that, in terms of defense genes, secondary metabolites, and volatile organic compounds, induced defense of nematode-infected plants could be affected by elevated CO(2), and that CO(2)-induced changes of plant resistance may lead to genotype-specific responses of plants to nematodes under elevated CO(2). The changes in resistance against nematodes, however, were small relative to those reported for chewing insects.

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Foliar chemical components of tomato genotypes grown under ambient and elevated CO2 without (“-”) and with M. incognita; plants with M. incognita were sampled 7 days post-inoculation (7 dpi) and 14 dpi.Each value represents the average (±SE) of three replicates. Different lowercase letters indicate significant differences among combinations of nematode and CO2 level within the same tomato genotype (LSD test: d.f. = 5, 12; P<0.05). Different uppercase letters indicate significant differences among tomato genotypes within the same CO2 and nematode treatment (LSD test: d.f. = 2, 6; P<0.05).
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pone-0019751-g002: Foliar chemical components of tomato genotypes grown under ambient and elevated CO2 without (“-”) and with M. incognita; plants with M. incognita were sampled 7 days post-inoculation (7 dpi) and 14 dpi.Each value represents the average (±SE) of three replicates. Different lowercase letters indicate significant differences among combinations of nematode and CO2 level within the same tomato genotype (LSD test: d.f. = 5, 12; P<0.05). Different uppercase letters indicate significant differences among tomato genotypes within the same CO2 and nematode treatment (LSD test: d.f. = 2, 6; P<0.05).

Mentions: Elevated CO2 increased the protein level of 35S plants and the foliar TNC:N ratio of all three genotypes. In contrast, elevated CO2 reduced the total phenolics and flavonoids of all the genotypes and the condensed tannins level of spr2 plants (Figure 2, Table S2). Regardless of CO2 level, uninfected Wt plants had the highest foliar TNC:N ratio among the genotypes. Furthermore, regardless of CO2 level, the 7-dpi treatment reduced whereas the 14-dpi treatment increased amino acid level of spr2 plants. The 14-dpi treatment increased the protein level of all the genotypes and the TNC:N ratio of all the genotypes under ambient CO2. Regardless of CO2 level, the 14-dpi treatment reduced total phenolics and flavonoids of Wt plants and flavonoids of 35S plants but increased condensed tannins of spr2 plants (Figure 2).


Elevated CO2 influences nematode-induced defense responses of tomato genotypes differing in the JA pathway.

Sun Y, Yin J, Cao H, Li C, Kang L, Ge F - PLoS ONE (2011)

Foliar chemical components of tomato genotypes grown under ambient and elevated CO2 without (“-”) and with M. incognita; plants with M. incognita were sampled 7 days post-inoculation (7 dpi) and 14 dpi.Each value represents the average (±SE) of three replicates. Different lowercase letters indicate significant differences among combinations of nematode and CO2 level within the same tomato genotype (LSD test: d.f. = 5, 12; P<0.05). Different uppercase letters indicate significant differences among tomato genotypes within the same CO2 and nematode treatment (LSD test: d.f. = 2, 6; P<0.05).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3101209&req=5

pone-0019751-g002: Foliar chemical components of tomato genotypes grown under ambient and elevated CO2 without (“-”) and with M. incognita; plants with M. incognita were sampled 7 days post-inoculation (7 dpi) and 14 dpi.Each value represents the average (±SE) of three replicates. Different lowercase letters indicate significant differences among combinations of nematode and CO2 level within the same tomato genotype (LSD test: d.f. = 5, 12; P<0.05). Different uppercase letters indicate significant differences among tomato genotypes within the same CO2 and nematode treatment (LSD test: d.f. = 2, 6; P<0.05).
Mentions: Elevated CO2 increased the protein level of 35S plants and the foliar TNC:N ratio of all three genotypes. In contrast, elevated CO2 reduced the total phenolics and flavonoids of all the genotypes and the condensed tannins level of spr2 plants (Figure 2, Table S2). Regardless of CO2 level, uninfected Wt plants had the highest foliar TNC:N ratio among the genotypes. Furthermore, regardless of CO2 level, the 7-dpi treatment reduced whereas the 14-dpi treatment increased amino acid level of spr2 plants. The 14-dpi treatment increased the protein level of all the genotypes and the TNC:N ratio of all the genotypes under ambient CO2. Regardless of CO2 level, the 14-dpi treatment reduced total phenolics and flavonoids of Wt plants and flavonoids of 35S plants but increased condensed tannins of spr2 plants (Figure 2).

Bottom Line: In the current study, we tested the hypothesis that elevated CO(2) will favor the salicylic acid (SA)-pathway defense but repress the jasmonic acid (JA)-pathway defense of plants against plant-parasitic nematodes.Our results suggest that, in terms of defense genes, secondary metabolites, and volatile organic compounds, induced defense of nematode-infected plants could be affected by elevated CO(2), and that CO(2)-induced changes of plant resistance may lead to genotype-specific responses of plants to nematodes under elevated CO(2).The changes in resistance against nematodes, however, were small relative to those reported for chewing insects.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Integrated Management of Pest and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.

ABSTRACT
Rising atmospheric CO(2) concentrations can affect the induced defense of plants against chewing herbivores but little is known about whether elevated CO(2) can change the induced defense of plants against parasitic nematodes. This study examined the interactions between the root-knot nematode Meloidogyne incognita and three isogenic tomato (Lycopersicon esculentum) genotypes grown under ambient (390 ppm) and elevated (750 ppm) CO(2) in growth chambers. In a previous study with open-top chambers in the field, we reported that elevated CO(2) increased the number of nematode-induced root galls in a JA-defense-dominated genotype but not in a wild-type or JA-defense-recessive genotype. In the current study, we tested the hypothesis that elevated CO(2) will favor the salicylic acid (SA)-pathway defense but repress the jasmonic acid (JA)-pathway defense of plants against plant-parasitic nematodes. Our data showed that elevated CO(2) reduced the JA-pathway defense against M. incognita in the wild-type and in a genotype in which defense is dominated by the JA pathway (a JA-defense-dominated genotype) but up-regulated the SA-pathway defense in the wild type and in a JA-defense-recessive genotype (jasmonate-deficient mutant). Our results suggest that, in terms of defense genes, secondary metabolites, and volatile organic compounds, induced defense of nematode-infected plants could be affected by elevated CO(2), and that CO(2)-induced changes of plant resistance may lead to genotype-specific responses of plants to nematodes under elevated CO(2). The changes in resistance against nematodes, however, were small relative to those reported for chewing insects.

Show MeSH