The Arabidopsis ROP-activated receptor-like cytoplasmic kinase RLCK VI_A3 is involved in control of basal resistance to powdery mildew and trichome branching

Abstract

Reference: Reiner T, Hoefle C, The Arabidopsis ROP-activated receptor-like cytoplasmic kinase RLCK VI_A3 is involved in control of basal resistance to powdery mildew and trichome branching. Plant Cell Rep 34:457-468. 2The final publication is available at Springer via http://dx.doi.org/doi: 10.1007/s00299-014-1725-1 KEY MESSAGEThe Arabidopsis receptor-like cytoplasmic kinase AtRLCK VI_A3 is activated by AtROPs and is involved in trichome branching and pathogen interaction. Key words:Receptor-like cytoplasmic kinase (RLCK), RAC/ROP GTPase, Arabidopsis thaliana, Erysiphe cruciferarum, Trichome Reference: Reiner T, Hoefle C, The Arabidopsis ROP-activated receptor-like cytoplasmic kinase RLCK VI_A3 is involved in control of basal resistance to powdery mildew and trichome branching. Plant Cell Rep 34:457-468. 3The final publication is available at Springer via http://dx.doi.org

Signals fly when kinases meet Rho-of-plants (ROP) small G-proteins

“…Therefore, barley HvRACs and HvRBK1 may function together in cortical microtubule dynamics, during the interaction with invading fungal pathogens. The silencing of the closest Arabidopsis homologue of HvRBK1, AtRLCK VI_A3, supported fungal susceptibility in a similar way to its barley counterpart [46].…”

“…The members of the RLCK VI_A subfamily [43,44,46], as well as their homologues from Medicago truncatula [44] and barley [45], bind to GTP-bound active but not to the GDP-bound inactive ROP GTPases in vitro, in yeast, and in planta.…”

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Several ROP-interacting kinases have been identified in yeast two-hybrid protein-protein interaction screens, using constitutively active ROP/RAC GTPases as baits. These kinases include RECEPTOR-LIKE CYTOPLASMIC KINASEs (RLCKs) from Medicago truncatula [44] and Arabidopsis [43,44,46], as well as barley [45]. RLCKs, based on the sequence of their kinase domain, belong to the large receptor-like kinase family.…”

A barley SKP1‐like protein controls abundance of the susceptibility factor RACB and influences the interaction of barley with the barley powdery mildew fungus

“…HvMAGAP1 interacts with HvRACB and limits the susceptibility of barley to Bgh , hence reflecting the regulatory function of ROPGAPs in controlling the signalling output of ROP GTPases. Similar to that described for barley, T‐DNA insertion lines of Arabidopsis AtROPGAP1 and AtROPGAP4 , and of the orthologue AtRLCK VI_A3 , show enhanced susceptibility to the powdery mildew fungus Erysiphe cruciferarum (Hoefle et al ., ; Huesmann et al ., ; Reiner et al ., ). In the barley– Bgh interaction, the CRIB motif protein HvRIC171 is supposed to be a downstream effector of HvRACB as it interacts with activated, but not inactive, HvRACB, and supports the accommodation of fungal haustoria, similar to CA HvRACB (Schultheiss et al ., ).…”

ROP GTPases Structure-Function and Signaling Pathways

“…Class VI Receptor-Like Cytoplasmic Kinases (RLCKs) belong to the large superfamily of RLKs, which are involved in a variety of cellular processes, including plant growth, development, and immune responses (Jurca et al, 2008;Lin et al, 2013b). RLCKs of the VI class appear to be downstream ROP effectors that regulate the pathogen response (Molendijk et al, 2008;Huesmann et al, 2012;Reiner et al, 2015). Barley (Hordeum vulgare) HvRBK1 is a type VI_A RLCK that is activated by HvRACB upon infection by the fungal pathogen Blumeria graminis f. sp.…”