Jatropha (Jatropha curcas L.) is a shrub or tree belonging the genus Euphorbiaceae and is cultivated in a tropical regions including South America, South-East Asia, India and Africa. Jatropha possibly is adapted to grow in a wide range of environments for producing non-edible oils. The objective of the study is to determine effect of salt and drought on plant growth characteristics. Treatments are thus followed, 100 and 200 mM NaCl and 5 and 10% PEG. Various physiological parameters such leaf length and width, stomatal conductance, chlorophyll fluorescence and gene expression were investigated. The results showed that from 2 days onwards, 100 and 200mM NaCl treatments were significantly suppressed leaf length, width, and stomatal conductance, but 5% and 10% PEG treatments showed a similar trend of control plants. Gene expression of JcACBP of the 100 mM NaCl was slightly decreased compred to those of other treatments. These results indicate that 100 and 200 mM NaCl treatments significantly showed negative response, but 5 and 10% PEG treatments improved plant growth and development of Jatropha.
AtHMA3 is one of P1B-ATPase of Arabidopsis thaliana which transports and/or stores Cd and Pb in the plant cell. To test whether AtHMA3 can be used to develop enhanced resistance plant to Cd and Pb for phytoremediation, we overexpressed AtHMA3 in Columbia-0 using a pBI121vector containing the 35S promoter. To evaluate their Cd and Pb resistance, seeds of three different T3 homozygous(HMA3-1~3) and wild type plants(col-0) were germinated and grown on agar plates containing 50μM Cd, 500μM Pb and 50μM Cd+ 500μM Pb for 3 weeks. 35S::AtHMA3 grew better than wild type plants about 1.1-to 1.8-fold in Cd or Pb containg mediums. Fresh weights of all three lines of transgenic plants were 1.2-to 1.5-fold higher than those of wild type plants in Cd or Pb-containing medium. In addition to, we measured Cd and Pb content in both wild type and transgenic plants grown in solution with 50μM Cd, 500μM Pb and 50μM Cd+ 500μM Pb for 6 d. AtHMA3-overexpressing plants had consistently higher Cd and Pb contents than wild type plants. Chlorophyll contents were not significant difference between overlines and wild-types. These results show that HMA3 contributes to Cd and Pb resistance, and it might be useful for the phytoremediation.