Stress responsive proteins in coconut seedlings subjected to water, high-light, flooding and high-temperature stresses

摘要

Coconut seedlings of different cultivars and cross combinations were subjected to stresses like water, high temperature and flooding stresses independently. Results indicated increase in the concentration of heat stable protein fraction (HSPF) in leaftissue even when the totai protein concentration reduced due to stress. The percentage of HSPF in leaf tissue increased with decrease in leaf water potentials. Quantitative changes in proteins also were observed in leaf and root tissue due to temperature and flooding. In HSPF, proteins of ~66KDa are found in root and leaf tissue. Leaflet tissues have specific proteins in the range of -10 and -14 KDa which are not present in the root tissues. Two extra proteins 66 KDa and - 76 KDa appeared in water stressed WCT seedlings. They were also present in seedlings exposed to high light intensity (-1,500 mmol/m2/s) apart from an extra LMW HSP of 14.4 KDa. Among the MMW- proteins, protein of 53 KDa is present in all WCT samples. The LMW protein of 20.1 KDa, present in non-stress seedlings disappeared during water stress period. In temperature induced and flooded leaflet tissue, new proteins (LWIW range -17 KDa) were observed. In temperature induced root tissue, a protein band in the range of 30 KDa was observed but not in flooded root or in control root. Results indicate quantitative and qualitative variations in stress proteins in coconut seedlings subjected to different abiotic stresses.