TITLE:
Biotic Stress Induced Biochemical and Isozyme Variations in Ginger and Tomato by Ralstonia solanacearum
AUTHORS:
Sasidharan Sreedevi, Kulangara Nanu Remani, Sailas Benjamin
KEYWORDS:
Biotic Stress; Hydroponics; Stress Enzymes; R. solanacearum; L. esculentum; Z. officinale
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.8,
August
5,
2013
ABSTRACT: This unique study
evaluates the effects of Ralstonia solanacearum (Rs) induced biotic stress in
two cultivars, Zingiber officinale (ginger) and Lycopersicon esculentum (tomato). They were grown in pots and hydroponic systems
with controls; to induce biotic stress, about 8 × 104 colony forming units of Rs suspension was injected into the healthy test plants.
Upon induction of Rs stress, highly significant (p 0.01) biochemical changes (%) were noticed
in respect to controls: carbohydrate content was generally high in both plants;
while they showed decreased starch and protein contents; phenolics showed a swing
of decrease or increase between pot and hydroponic systems; and all plants in general
showed higher (3-6 fold) proline content upon induction of biotic stress.
Regarding oxidative stress isozymes (OSE), superoxide dismutase (EC 1.15.1.1) isozymes were normally 3, but treated hydroponics had
4 with comparable relative mobility values; peroxidase (EC 1.11.1.7) isozymes
were generally 2, except for treated hydroponic tomato. Briefly, Rs induced biotic
stress caused wilt symptoms in ginger, but did not affect tomato though its
biochemical and OSE patterns especially in those grown as hydroponics were elicited
to significantly higher levels.