Chloroplast membrane lipid remodeling protects against dehydration by limiting membrane fusion and distortion

Autor: Choon-Peng Chng, Wei Ma, K. Jimmy Hsia, Changjin Huang, Kun Wang
Přispěvatelé: School of Mechanical and Aerospace Engineering, School of Biological Sciences, School of Chemical and Biomedical Engineering
Rok vydání: 2021
Předmět:
Zdroj: Plant Physiol
ISSN: 1532-2548
0032-0889
Popis: Dehydration damages the structural integrity of the chloroplast membrane and, consequently, the normal photosynthetic function of this organelle. Remodeling of galactolipids by converting monogalactosyl-diacylglycerol (MGDG) to digalactosyl-diacylglycerol (DGDG) and oligo-galactolipids is an effective adaptation strategy for protecting against dehydration damage to the chloroplast membrane. However, detailed molecular mechanisms are missing. In this study, by performing molecular-level simulations of bi-lamellar membranes under various dehydration conditions, we find that MGDG-to-DGDG remodeling protects the chloroplast membrane in a unique manner by simultaneously dictating both the extent and the pattern of fusion stalks formed with the apposed membrane. Specifically, MGDG-rich membranes form elongated stalks at a moderate dehydration level, whereas DGDG-rich membranes form smaller, rounded stalks. Simulations of wild-type and mutant Arabidopsis (Arabidopsis thaliana) outer chloroplast membranes further confirm that the mutant membrane without galactolipid remodeling is more susceptible to membrane fusion due to its higher MGDG content. Our work reveals the underlying physical mechanisms that govern the pattern and extent of membrane fusion structures, paving the way for rational genetic engineering of crops with improved dehydration tolerance. Ministry of Education (MOE) Nanyang Technological University Accepted version This work was supported by Nanyang Technological University under its Accelerating Creativity and Excellence (ACE) grant (grant no. NTU–ACE2020-07 to W.M., K.J.H and C.H.), Nanyang Technological University start-up grants (grant nos. M4082428 to K.J.H. and M4082352 to C.H.), and Ministry of Education, Singapore, under its Academic Research Fund Tier 1 (grant no. RG92/19).
Databáze: OpenAIRE