Chickpea is an annual self-pollinated moderately drought-tolerant legume crop plant. Chickpea is considered as a major source of protein rich food for developing countries; however, unfortunately, the productivity of this grain legume is adversely affected by environmental stresses.The bio-synthesis of Raffinose family oligosaccharides (RFO) is a highly event flowering plant and implicated in diverse physiological and development process in plant .Galactinol Synthase a member of the glycosyltransferase 8(GT8) family is a key regulatory enzyme of RFO bio synthase that catalyzes the formation if galactinol (1-0-alpha-D-galactopyranosyl-myo-inositol) from UDP-galactose and myo-inositol.
These RFO including Raffinose perform several physiological and development function in plant. RFO transport carbohydrates in member of numerous family. AtGoIS1 is induce by heat ,salinity and drought stress, while AtGoIS2 is induced only drought and salinity stress AtGoIS3 gene is induced exclusively under cold stress.The role of GoIS in abiotic stress tolerant in chickpea, initially GoIS activity was examined in chickpea seedling subsequently total crud protein were extract from each sample and GoIS activity was analyzed.
The high rate or up-regulation of GoIS activity observed in chickpea seedling challenged with heat stress where approximately 2-5 fold more activity than control GoIS is also response to oxidative stress.This activity also examined in seedling challenged with salinity, drought and dehydration. These result shows a possible role of GoIS in stress tolerant in chickpea.GoIS is known to be a regulatory enzyme of RFO bio synthesis.
Hence we were also interested to analyses the control of galactinol, raffinose and substrate molecule myo-inositol in chickpea seedling challenged or not with these stress.GoIS activity response the environment stress. Now we investigated CaGoIS1 and GoIS2 transcript accumulation through QPCR. We observed CaGoIS1 and CaGoIS2 were induced in response to different abiotic stress. Increased accumulation of CaGoIS1 and CaGoIS2 transcript was observed under all stress condition through maximum accumulation found with heat and oxidative stress, chickpea seedling accumulation significantly more CaGoIS1 transcript(25 to 30 fold), CaGoIS2 transcript(3 to 5fold) indicating that heat and oxidative stress preferentially induced CaGoIS1 and CaGoIS2. These result indicates that increase GoIS activity is possible a consequence of transcription induction of these two genes under stress condition.CaGolS1 and CaGolS2 transformed lines accumulate increased galactinol and raf?nose content and exhibit improved tolerance to heat and oxidative stress by limiting stress-induced excess ROS accumulation and consequent lipid per-oxidation.