This investigation was carried out at the Department of Plant Science and Agricultural Resources, Khon Kaen University in the rainy season of 2011. The objective of this study was to identify
proteins in leaves of drought-susceptible peanut plants when regulated by progressive water stresses. The drought-susceptible peanut plants of Khon Kaen 4 cultivar were grown in pots under controlled environment. At day 30 after seed emergence, the plants were subjected to stress conditions for 5 and 6 days. The results showed that withheld water supply for 5 and 6 days gave moderately and severely water stresses, respectively. Under moderate
water stress conditions, two up-regulated and eight down-regulated
proteins were attained. The up-regulated
proteins were striated fibre assembling and
flap endonuclease 1. The down-regulated
proteins were
peptidyl-prolyl cis-trans isomerase FKBP4,
tRNA(Ile)-
lysidine synthase, chloroplastic, chloroplastic
thioredoxin F-type, cytidinedeaminase 7, ALF domain class
transcription factor,
nudix hydrolase 8, pentatricopeptide repeat super-family
protein, putative and
ribulose-1,5-bisphosphate carboxylase/
oxygenase, a large sub-unit. Under severe
water stress conditions, two
proteins, i.e.,
tRNA(Ile)
lysidine synthase, chloroplastic and ALF domain class
transcription factor did not change their relative abundance significantly where it indicated drought acclimation. The remaining
proteins displayed significant changes and the changes were the same as those found in the peanut leaves when deprived water for 5 days. Up-regulated
proteins are responsible for alleviating oxidative damages to plant genome and mediating plants responsive to the environmental factors in providing mechanical support, barriers and a rapid transport route. Down-regulated
proteins were associated with drought susceptibility of the Khon Kaen 4 peanut plants.