Elevated CO2 influences host plant defense response in chickpea against Helicoverpa armigera uri icon

abstract

  • Global atmospheric concentration of CO2 islikely to increase from 350 to 750 ppm over the next100 years. The present studies were undertaken to understandthe effects of elevated CO2 on enzymatic activity andsecondary metabolites in chickpea in relation to expressionof resistance to pod borer, Helicoverpa armigera. Fifteenday-old chickpea plants (ICCL 86111?resistant and JG11?commercial cultivar) grown in the greenhouse weretransferred to open-top chambers (OTC) and kept under350, 550 and 750 ppm of CO2. Twenty neonates of H.armigera were released on each plant at 7 days aftershifting the pots to the OTCs. Un-infested plants weremaintained as controls. After 7 days of infestation, theactivities of defensive enzymes (peroxidase (POD),polyphenol oxidase (PPO), phenylalanine ammonia lyase(PAL) and tyrosine ammonia lyase (TAL)) and amounts oftotal phenols and condensed tannins increased with anincrease in CO2 concentration in chickpea. The nitrogenbalance index was greater in plants kept at 350 ppm CO2than in plants kept under ambient conditions. The H.armigera-infested plants had higher H2O2 content;amounts of oxalic and malic acids were greater at 750 ppmCO2 than at 350 ppm CO2. Plant damage was greater at350 ppm than at 550 and 750 ppm CO2. This informationwill be useful for understanding effects of increased levelsof CO2 on expression of resistance to insect pests todevelop strategies to mitigate the effects of climate change

publication date

  • 2016
  • 2016