Vol. 7, Issue 6 (2019)
Spatial pattern and longevity of induction of plant defense enzymes in cotton
Author(s): VA Vijayashanthi and KP Sanjayan
Abstract: Plants often increase their resistance to herbivores by locally increasing their production of defensive compounds at the site of damage, as well as systemically on undamaged leaves. The strength of these plant responses can vary depending on the amount, concentration, and location of damage. The spatial pattern/mapping of induction of defense enzymes viz., polyphenol oxidase (PPO), peroxidase (POD), lipoxygenase (LOX) and protease inhibitor (PI) in the damaged plants of cotton varied with the type of damage employed have been studied. The results of the spatial pattern of expression of defense proteins in cotton in relation to different induction regimes at four leaf positions of cotton plant showed that plant systemic induction by Spodoptera litura with a 3.27 fold increase in PPO activity in terminal leaf (plant systemic) followed by a 2.43 fold increase in upper leaf and the induction was localized to damaged leaf and the leaf adjacent to the damaged leaf with a 2.08 fold increase and 2.04 fold increase respectively due to damage by Aphis gossypii. However induction of POD and LOX was localized irrespective of the type of inducing agent. Maximum and significant increase in PI activity against S. litura damage was observed in damaged leaf position (54.66%) compared to that of control plants (14.33%), followed by adjacent leaf, terminal and lower leaf. For A. gossypii feeding damage, high PI activity was recorded only at damaged and adjacent leaf (57.66 and 31% respectively) indicating induction only up to leaf systemic position. The PPO activity and levels of chymotrypsin inhibitors expressed in Gossypium hirsutum peaked on the fifth day of the treatment and they persisted at significantly higher levels even on the seventh day after induction by S. litura. Damage by A. gossypii showed highest PI activity on 3rd DAT and no significant increase was observed thereafter but the activity was significantly different from the control. The longevity of the induced response offers longer protection against herbivory is of great significance in pest management.
Pages: 1502-1507 | 279 Views 56 Downloads
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How to cite this article:
VA Vijayashanthi, KP Sanjayan. Spatial pattern and longevity of induction of plant defense enzymes in cotton. Int J Chem Stud 2019;7(6):1502-1507.
