Atmospheric CO2 level is increasing rapidly and is expected to double in the next century. Most studies addressing how plant-herbivore interactions are affected by elevated CO2 have focused on aboveground herbivory. Few studies, however, have considered how CO2 affects interactions between plants and belowground herbivores. The current study examined how three isogenic tomato genotypes that differ in the JA pathway responded to elevated CO2, both alone and combined with M. incognita infection. The three isogenic genotypes, which differed in the jasmonic acid (JA) pathway, were suppressor of prosystemin-mediated responses2 (spr2) mutant plants, 35S::prosystemin (35S) plants, and wild type (Wt) plants.
The three genotypes had a higher C: N ratioand a higher growth rate under elevated CO2 than under ambient CO2. Elevated CO2 increased the number of nematode-induced galls on 35S but not on Wt or spr2 roots. We note that 35S plants had the most resistance to M. incognita, and the jasmonate-deficient mutant spr2 wasnot significantly more susceptible than the Wt under ambient CO2. It follows that, although enhanced systemic defense in 35S can increase the resistance to nematodes, the JA-pathway is not the only defense mechanism involved in plant resistance to nematodes.
Our results suggest that CO2 enrichment may not only alter plant C:N ratio but can also alter the physiological trade-off between growth and defense in some genetically modified plants and thereby alter the interactions between nematode and tomato genotypes.
This paper has been published in Plant, Cell & Environment (Sun Y., Cao H., Yin J., Kang L. & Ge F. 2010. Elevated CO2 changes the interactions between nematode and tomato genotypes differing in the JA pathway. 33: 729-739) . This project was supported by the “National Basic Research Program of China” (973 Program) (No. 2006CB102002) and the Innovation Program of Chinese Academy of Science (KSCX2-YW-N-006).
The 5th International Conference on Rodent Biol...
