Choline transporter‐like1 (CHER1) is crucial for plasmodesmata maturation in Arabidopsis thaliana. (17th January 2017)

• Record Type: Journal Article
• Authors: Kraner, Max E.; Link, Katrin; Melzer, Michael; Ekici, Arif B.; Uebe, Steffen; Tarazona, Pablo; Feussner, Ivo; Hofmann, Jörg; Sonnewald, Uwe
• Is Part Of: Plant journal. Volume 89:Number 2(2017)
• Page Start: 394
• Page End: 406
• Publication Date: 2017-01-17
• Subjects: Arabidopsis thaliana -- At3g15380 -- CHER1 -- choline transporter‐like 1 -- lipidomics -- movement protein -- MP17 -- Plasmodesmata; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.13393
• Languages: English
• ISSNs: 0960-7412

Abstract

Summary: Plasmodesmata (PD) are microscopic pores connecting plant cells and enable cell‐to‐cell transport. Currently, little information is known about the molecular mechanisms regulating PD formation and development. To uncover components of PD development we made use of the 17 kDa movement protein (MP17) encoded by the Potato leafroll virus (PLRV). The protein is required for cell‐to‐cell movement of the virus and localises to complex PD. Forward genetic screening for Arabidopsis mutants with altered PD binding of MP17 revealed several mutant lines, while molecular genetics, biochemical and microscopic studies allowed further characterisation. Map‐based cloning of one mutant revealed a point mutation in the choline transporter‐like 1 (CHER1) protein, changing glycine 247 into glutamate. Mutation in CHER1 resulted in a starch excess phenotype and stunted growth. Ultrastructure analysis of shoot apical meristems, developing and fully developed leaves showed reduced PD numbers and the absence of complex PD in fully developed leaves. This indicates that cher1 mutants are impaired in PD formation and development. Global lipid profiling revealed only slight modifications in the overall lipid composition, however, altered composition of PD‐associated lipids cannot be ruled out. Thus, cher1 is devoid of complex PD in developed leaves and provides insights into the formation of complex PD at the molecular level. Significance Statement: Plasmodesmata enable cell‐to‐cell transport, but the molecular mechanisms regulating their formation and development are not fully understood. We screened for mutants defective in binding a virus movement protein at plasmodesmata and thus identified that choline transporter‐like 1 (CHER1), which is important for genesis of secondary plasmodesmata in the shoot apical meristem and for maturation of complex PD during leaf development.