Abstract
Abscisic acid (ABA) is an important phytohormone involved in the regulation of plant growth, development and adaption to various environmental challenges. Regulatory component of ABA receptor 1 (RCAR1, also known as PYL9) acts as a newly discovered ABA receptor in Arabidopsis. To identify interacting partners of RCAR1, we have carried out a yeast two-hybrid screen. One protein was identified, ArathEULS3, which belongs to the Euonymus europaeus lectin (EUL) family of plant lectins. The interaction between RCAR1 and ArathEULS3 was confirmed by GST pull-down assay. Transient expression of RCAR1-EGFP and ArathEULS3-EGFP in Arabidopsis protoplasts revealed that both proteins were mainly expressed in cytoplasm and nucleus. Real time qRT-PCR analysis showed that over-expression of RCAR1 increased the expression of ArathEULS3. Furthermore, up-regulating ArathEULS3 in Arabidopsis conferred ABA hypersensitivity during post-germination growth and enhanced drought tolerance, but did not affect the expression of RD29B, RAB18 and RD29A (ABA- and drought-responsive genes). Previously, ArathEULS3 was shown as a carbohydrate-binding plant lectin. Thus, our results reveal a direct connection between abiotic stress responses and plant lectin.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
