TITLE:
Ralstonia solanacearum Induction Causes Biochemical and Oxidative Stress Isozyme Variations in Mangroves without Wilt
AUTHORS:
Sasidharan Sreedevi, Sreedharan Sajith, Kulangara Nanu Remani, Sailas Benjamin
KEYWORDS:
R. solanacearum; Avicennia officinalis L.; Derris trifoliata Lour.; Excoecaria agallocha L.
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.10,
October
9,
2013
ABSTRACT: We evaluated the effects of Ralstonia solanacearum (Rs)
induced biotic stress in three mangroves, viz., Avicennia officinalis, Derris trifoliata and Excoecaria agallocha. These plants were grown in pots as well as hydroponic systems with
sufficient controls, and about 8 × 104 colony forming units of Rs suspension was injected into the healthy
test plants (saplings). The plants were subjected to biochemical and isozyme
analyses. Upon induction of Rs stress,
highly significant (p 0.01) biochemical changes
(%) were noticed in respect to controls: carbohydrate content was generally
high (24-36) in all plants; hydroponic mangroves showed higher starch content,
mangroves under hydroponic system showed increased reducing
sugars (29-46), almost all mangroves showed increased protein content; phenolics
showed a swing of decrease or increase between plants grown in pot and
hydroponic systems; and all plants in general showed higher proline content.
Regarding oxidative stress isozymes (OSE) and superoxide dismutase
(EC1.15.1.1), mangroves showed 1 or 2 additional isozymes with
comparable relative mobility; similarly 1 or 2 additional peroxidase
(EC1.11.1.7) isozymes were found in mangroves grown under hydroponic system.
Briefly, Rs induced biotic stress did
not cause any wilt symptom in all the 3 mangroves tested, but their normal
biochemical and OSE patterns, especially of those grown as hydroponics were
elicited to significantly higher levels.