Further insight into the involvement of PII1 in starch granule initiation in Arabidopsis leaf chloroplasts

Autor: Vandromme, C. (Camille), Spriet, C. (Corentin), Putaux, J. (Jean‐Luc), Dauvillee, D. (David), Courseaux, A. (Adeline), D'hulst, C. (Christophe), Wattebled, F. (Fabrice)
Přispěvatelé: Université de Lille, CNRS, Unité de Glycobiologie Structurale et Fonctionnelle (UGSF) - UMR 8576, Centre de Recherches sur les Macromolécules Végétales [CERMAV ], Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Plateformes Lilloises en Biologie et Santé - UAR 2014 - US 41 (PLBS), Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: New Phytologist
New Phytologist, 2023, 239 (1), pp.132-145. ⟨10.1111/nph.18923⟩
ISSN: 0028-646X
1469-8137
Popis: International audience; The control of starch granule initiation in plant leaves is a complex process that requires active enzymes like Starch Synthase 4 and 3 (SS4 or SS3) and several noncatalytic proteins such as Protein Involved in starch Initiation 1 (PII1). In Arabidopsis leaves, SS4 is the main enzyme that control starch granule initiation, but in its absence, SS3 partly fulfills this function. How these proteins collectively act to control the initiation of starch granules remains elusive. PII1 and SS4 physically interact, and PII1 is required for SS4 to be fully active. However, Arabidopsis mutants lacking SS4 or PII1 still accumulate starch granules. Combining pii1 KO mutation with either ss3 or ss4 KO mutations provide new insights of how the remaining starch granules are synthesized. The ss3 pii1 line still accumulates starch, while the phenotype of ss4 pii1 is stronger than that of ss4. Our results indicate first that SS4 initiates starch granule synthesis in the absence of PII1 albeit being limited to one large lenticular granule per plastid. Second, that if in the absence of SS4, SS3 is able to initiate starch granules with low efficiency, this ability is further reduced with the additional absence of PII1.
Databáze: OpenAIRE
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