Rubisco accumulation is important for the greening of the fln2-4 mutant in Arabidopsis. (July 2015)

• Record Type: Journal Article
• Authors: Huang, Chao; Yu, Qing-Bo; Yuan, Xin-Bo; Li, Zi-Ran; Wang, Jing; Ye, Lin-Shan; Xu, Ling; Yang, Zhong-Nan
• Is Part Of: Plant science. Volume 236(2015:Jul.)
• Page Start: 185
• Page End: 194
• Publication Date: 2015-07
• Subjects: FLN2 fructokinase-like protein2 -- Rubisco ribulose-1, 5-bisphosphate carboxylase/oxygenase -- PEP plastid-encoded plastid RNA polymerase -- Pal palatinose -- Suc sucrose -- Glu glucose -- Fru fructose -- CTP chloroplast transit peptide -- SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis -- EtBr ethidium bromide; Arabidopsis -- Delayed greening -- FLN2 -- PEP -- Rubisco; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2015.04.005
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: Sugar serves as an energy source rather than a signaling molecule to support the greening of fln2-4 . Expression of a nuclear-encoded rbcL gene can partially rescue the albino phenotype of fln2-4 . Rapid Rubisco accumulation is critical for early seedling growth. Abstract: The fructokinase-like protein2 (FLN2) is a component of the PEP complex. FLN2 knockout mutants displayed a delayed greening phenotype on sucrose-containing medium. Our previous work indicated that partial PEP activity is essential for its greening phenotype. In this study, we further report that sufficient Rubisco accumulation is critical for fln2-4 greening. Sugar serves many important functions, such as an energy source and signaling molecule. Through pharmacological experiments using a sugar analog and sugar signaling inhibitor, we demonstrate that sugar serves as energy to support the fln2-4 greening. Seed-reserve and photosynthetic CO2 -fixation are the primary energy sources for early seedling growth. No obvious differences were observed in the seed-reserve of the wild-type and fln2-4 by comparing their seed size and dark-germination, indicating that the defective carbon fixation may account for the energy deficit in fln2-4 during its early seedling growth. The Rubisco content was low in fln2-4, but it rapidly accumulated during the greening of fln2-4 . Expression of a nuclear-encoded rbcL gene facilitates Rubisco accumulation and partially complements the mutant defects. These results suggest that the Rubisco accumulation is critical for fln2-4 greening. In summary, the rapid Rubisco accumulation that depends on sufficient PEP activity is important for normal seedling growth.