The Role Of14-3-3Protein In EATP Regulated Root Growth Of Arabidopsis Thaliana

Root is a critical organ which is in charge of nutrients absorption and growth&development modulation. Extracellular ATP (eATP) is an important extracellularmessenger in plant cell and plays a key role in regulating growth and development.14-3-3proteins are regulatory proteins which are involved in plant growth,development and stress tolerance. Here, to verify eATP signal transductionmechanism, the role of14-3-3proteins in eATP-regulated root growth anddevelopment of Arabidopis thaliana seedlings were investigated.Wild-type (col-0), lost-of-function mutants of some14-3-3proteins (grf5,grf7,grf8and grf9) were used as material. Growth and developmental parameters ofseedlings which were growing in medium containning serial concentrated ATP werecarefully detected. These parameters include main root length, lateral root numberand gravitropic growth behavior.Results showed that added100,200or300μM ATP inhibited main root growthin a close-dependent manner both in wild-type and all mutants. Indicating that14-3-3proteins GRF5, GRF7, GRF8, GRF9may be not involved in eATP-inhibited mainroot elongation. Meanwhile, eATP promoted generation and growth of lateral roots ina dose-dependent manner in wild-type. However, such a promotion was not detectedin grf5,grf7,grf8and grf9mutants. Indicating that GRF5, GRF7, GRF8, GRF9maybe possibly involved in eATP promoted lateral root generation.In wild-type, added ATP significantly inhibited gravitropic growth of roots,similar effects were were also found in grf7, grf8and grf9mutants. However,gravitropic growth of grf5seedling roots still exist after eATP stimulation, indicatingthat GRF5may be involved in eATP-inhibited root gravitropism.