Role of cytokinin in growth and development of groundnut: A transgenic approach
Loading...
Files
Date
2013-11-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Sciences, Bengaluru
Abstract
Transgenic lines with bacterial ipt gene to increase endogenous cytokinin
concentration in groundnut variety TMV-2 was developed and promising putative
transgenic lines were selected. In the present investigation, 54 putative transgenic lines in
T3 generation were analyzed for further physiological and yield characters. Based on leaf
chlorophyll content and pod yield, 49 lines were advanced to T5 generation. Transgenic
lines on an average had 27 and 32 percent more chlorophyll at the end of NaCl and Ethrel
stress and also higher NRA activity. Based on chlorophyll content, NRA, pod yield and
biomass, 22 lines were promoted to T6
generation. Transgenic lines maintained relatively
higher leaf chlorophyll content and membrane integrity in response to NaCl and Ethrel
stress. Transgenic lines also showed higher NRA activity, bigger leaves, more biomass
production, pod number and pod weight at harvest. Based on pod yield per plant, 11
lines were advanced to T7 generation. Transgenic lines maintained more green leaf area,
higher pod number and pod weight in two pot culture experiments conducted.
Based on PCR, RT-PCR and southern blot analysis, three ipt transgenic lines were
selected from previous generations to study influence of NaCl and moisture stress on
physiological and growth parameters under both stress and non-stress conditions.
Transgenic lines showed higher leaf chlorophyll content, nitrate reductase activity, less
membrane leakage and higher total leaf area both under non-stress, at the end of NaCl
stress and during recovery from NaCl stress. All the transgenic lines maintained higher
leaf area and biomass in shoot and root under both non stress and stress conditions. An
attempt was also made to develop transgenic groundnut lines maintaining high
endogenous cytokinin concentration by reducing the concentration of cytokinin
degrading enzyme-CKO by antisense approach. Groundnut transgenic plants overexpressing
pFGC5941: CKO gene was developed by Agrobacterium mediated inplanta
transformation. Putative transgenic lines were screened over different concentrations of
basta and CKO gene was confirmed by gene specific and bar primers in transgenic lines.
The putative transgenic lines showed significant increase in pod number, pod yield, total
shoot biomass accumulation and root weight per plant.
Description
Keywords
cytokinins, planting, transgenics, genes, enzymes, developmental stages, chlorophylls, biological development, vegetative propagation, selection