Elevated CO2 decreases the response of the ethylene signaling pathway in Medicago truncatula and increases the abundance of the pea aphid
Article first published online: 10 SEP 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
Volume 201, Issue 1, pages 279–291, January 2014
How to Cite
Guo, H., Sun, Y., Li, Y., Liu, X., Zhang, W. and Ge, F. (2014), Elevated CO2 decreases the response of the ethylene signaling pathway in Medicago truncatula and increases the abundance of the pea aphid. New Phytologist, 201: 279–291. doi: 10.1111/nph.12484
- Issue published online: 26 NOV 2013
- Article first published online: 10 SEP 2013
- Manuscript Accepted: 6 AUG 2013
- Manuscript Received: 15 MAY 2013
- National Basic Research Program of China. Grant Number: 2012CB114103
- National Nature Science Fund of China. Grant Numbers: 31170390, 31000854, 31221091
- Acyrthosiphon pisum (pea aphid);
- elevated CO2;
- Medicago truncatula ;
- nitrogen (N) metabolism;
- The performance of herbivorous insects is greatly affected by plant nutritional quality and resistance, which are likely to be altered by rising concentrations of atmospheric CO2.
- We previously reported that elevated CO2 enhanced biological nitrogen (N) fixation of Medicago truncatula, which could result in an increased supply of amino acids to the pea aphid (Acyrthosiphon pisum). The current study examined the N nutritional quality and aphid resistance of sickle, an ethylene-insensitive mutant of M. truncatula with supernodulation, and its wild-type control A17 under elevated CO2 in open-top field chambers.
- Regardless of CO2 concentration, growth and amino acid content were greater and aphid resistance was lower in sickle than in A17. Elevated CO2 up-regulated N assimilation and transamination-related enzymes activities and increased phloem amino acids in both genotypes. Furthermore, elevated CO2 down-regulated expression of 1-amino-cyclopropane-carboxylic acid (ACC), sickle gene (SKL) and ethylene response transcription factors (ERF) genes in the ethylene signaling pathway of A17 when infested by aphids and decreased resistance against aphids in terms of lower activities of superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO).
- Our results suggest that elevated CO2 suppresses the ethylene signaling pathway in M. truncatula, which results in an increase in plant nutritional quality for aphids and a decrease in plant resistance against aphids.