Generation and physiological characterization of genome-edited Nicotiana benthamiana plants containing zeaxanthin as the only leaf xanthophyll

• DOI: 10.1007/s00425-023-04248-3
• Publication Date: 2023-10-05T11:01:29Z
• Authors: Maria Sulli; Luca Dall’Osto; Paola Ferrante; Zeno Guardini; Rodrigo Lionel Gomez; Paola Mini; Olivia Costantina...; Giuseppe Aprea; Alessandro Nicolia; Roberto Bassi; Giovanni Giuliano
• Keywords: Photoprotection; Violaxanthin

Abstract Main conclusion Simultaneous genome editing of the two homeologous LCYe and ZEP genes Nicotiana benthamiana results in plants which all xanthophylls are replaced by zeaxanthin . Plant carotenoids act both as photoreceptors photoprotectants photosynthesis precursors apocarotenoids, include signaling molecules such abscisic acid (ABA). As dietary components, lutein have photoprotective functions human macula. We developed transient stable combinatorial methods, followed direct LC–MS screening for accumulation, simultaneous Lycopene Epsilon Cyclase ( ) Zeaxanthin Epoxidase present allopolyploid genome. Editing four resulted leaf were substituted zeaxanthin, but with different ABA levels growth habits, depending on severity ZEP1 mutation. In high-zeaxanthin lines, abundance major photosystem II antenna LHCII was reduced respect to wild-type trimeric state became unstable upon thylakoid solubilization. Consistent depletion LHCII, edited underwent a compensatory increase PSII/PSI ratios loss large-size PSII supercomplexes, while level PSI-LHCI supercomplex unaffected. Reduced activity mechanism NPQ shown plants, photoinhibition similar genotypes exposure excess light, consistent antioxidant role vivo.