Abstract
The whitefly-transmitted geminiviruses induce severe developmental abnormalities in plants. Geminivirus-encoded C4 protein functions as one of viral symptom determinants that could induce abnormal cell division. However, the molecular mechanism by which C4 contributes to cell division induction remains unclear. Here we report that tomato leaf curl Yunnan virus (TLCYnV) C4 interacts with a glycogen synthase kinase 3 (GSK3)/SHAGGY-like kinase, designed NbSKη, in Nicotiana benthamiana. Pro32, Asn34 and Thr35 of TLCYnV C4 are critical for its interaction with NbSKη and required for C4-induced typical symptoms. Interestingly, TLCYnV C4 directs NbSKη to the membrane and reduces the nuclear-accumulation of NbSKη. The relocalization of NbSKη impairs phosphorylation dependent degradation on its substrate-Cyclin D1.1 (NbCycD1;1), thereby increasing the accumulation level of NbCycD1;1 and inducing the cell division. Moreover, NbSKη-RNAi, 35S::NbCycD1;1 transgenic N. benthamiana plants have the similar phenotype as 35S::C4 transgenic N. benthamiana plants on callus-like tissue formation resulted from abnormal cell division induction. Thus, this study provides new insights into mechanism of how a viral protein hijacks NbSKη to induce abnormal cell division in plants.
Highlights
Geminiviruses cause devastating diseases in fields and economic losses in agriculture in the world [1,2,3,4,5,6,7]
We validated the interaction of tomato leaf curl Yunnan virus (TLCYnV) C4 and NbSKη in Y2H and bimolecular fluorescence complementation (BiFC) assays (S1A and S1B Fig)
A phylogenetic analysis revealed that NbSKη has a close homology with NsSKη in N. sylvestris, SlSKη in Solanum lycopersicum, BIN2-like protein PSK9 in Petunia hybrid, VvSKη in Vitis vinifera, GaSKη in Gossypium arboretum, and AtSKη in A. thaliana (S1C Fig)
Summary
Geminiviruses cause devastating diseases in fields and economic losses in agriculture in the world [1,2,3,4,5,6,7]. They have a single-stranded DNA genome, 2.5~3.0 kb, encoding 6~7 genes. Many geminiviruses replicate in differentiated cells that no longer contain detectable levels of host DNA polymerases and associated factors. To overcome this barrier and make a suitable environment for replication, geminiviruses induce the accumulation of DNA replication machinery in mature plant cells [8]. Beet severe curly top virus (BSCTV) C4 protein induces the expression of RKP, a gene encodes a RING finger E3 ligase, to regulate cell cycle [10]
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
