Abstract
High salinity causes remarkable inhibition on plant growth. On the other hand, plants have salt tolerant mechanisms against salinity. It is known that plants accumulate various chemical compounds under salt stress. Among them, polyamines, choline and osmoprotectants such as polyols and betaines are synthesized from S-adenosyl methionine (SAM). Therefore SAM synthesis is important in salt tolerance. However, it is still unclear how SAM is synthesized under saline conditions and contributes to salt tolerance.
In this study, we have investigated the effect of application of Methionine (Met), precursor of SAM, on the salinity-induced growth inhibition of Arabidopsis thaliana. Although the growth decreased under salt treatment, the damages became severe by adding Ethionine, analogous to Met, and were alleviated by applying Met. These results indicated that Met is necessary to salt tolerance at a whole-plant level. We are investigating how the transcripts of SAM synthesis-related genes are regulated under salt stress.
