|Changjiang Li, Hanmei Lu, Wei Li, Ming Yuan & Ying Fu. A ROP2-RIC1 pathway fine-tunes microtubule reorganization for salt tolerance in Arabidopsis. Plant, Cell and Environment. DOI: 10.1111/pce.12905|
A ROP2-RIC1 pathway fine-tunes microtubule reorganization for salt tolerance in Arabidopsis
Changjiang Li, Hanmei Lu, Wei Li, Ming Yuan & Ying Fu
Plant, Cell and Environment
The reorganization of microtubules induced by salt stress is required for Arabidopsis survival under high salinity conditions. RIC1 is an effector of Rho-related GTPase from plants (ROPs) and a known microtubule-associated protein. In this study, we demonstrated that RIC1 expression decreased with long-term NaCl treatment, and ric1-1 seedlings exhibited a higher survival rate under salt stress. We found that RIC1 reduced the frequency of microtubule transition from shortening to growing status and knockout of RIC1 improved the reassembly of depolymerized microtubules caused by either oryzalin treatment or salt stress. Further investigation showedthatconstitutivelyactiveROP2promotedthereassembly of microtubules and the survival of seedlings under salt stress. A rop2-1 ric1-1 double mutant rescued the saltsensitive phenotypeofrop2-1,indicatingthat ROP2 functions in salt tolerance through RIC1. Although ROP2 did not regulate RIC1 expression upon salt stress, a quick but mild increase of ROP2 activity was induced, led to reduction of RIC1 on microtubules. Collectively, our study reveals an ROP2-RIC1 pathway that ﬁne-tunes microtubule dynamics in response to salt stress in Arabidopsis. Thisﬁnding not only reveals a new regulatory mechanism for microtubule reorganization under salt stress but also the importance of ROP signalling for salinity tolerance.