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Zhu L, Dou L, Shang H, Li H, Yu J, Xiao G. GhPIPLC2D promotes cotton fiber elongation by enhancing ethylene biosynthesis. iScience 2021; 24:102199. [PMID: 33718844 PMCID: PMC7921840 DOI: 10.1016/j.isci.2021.102199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 01/13/2021] [Accepted: 02/12/2021] [Indexed: 11/29/2022] Open
Abstract
Inositol-1,4,5-trisphosphate (IP3) is an important second messenger and one of the products of phosphoinositide-specific phospholipase C (PIPLC)-mediated phosphatidylinositol (4,5) bisphosphate (PIP2) hydrolysis. However, the function of IP3 in cotton is unknown. Here, we characterized the function of GhPIPLC2D in cotton fiber elongation. GhPIPLC2D was preferentially expressed in elongating fibers. Suppression of GhPIPLC2D transcripts resulted in shorter fibers and decreased IP3 accumulation and ethylene biosynthesis. Exogenous application of linolenic acid (C18:3) and phosphatidylinositol (PI), the precursor of IP3, improved IP3 and myo-inositol-1,2,3,4,5,6-hexakisphosphate (IP6) accumulation, as well as ethylene biosynthesis. Moreover, fiber length in GhPIPLC2D-silenced plant was reduced after exogenous application of IP6 and ethylene. These results indicate that GhPIPLC2D positively regulates fiber elongation and IP3 promotes fiber elongation by enhancing ethylene biosynthesis. Our study broadens our understanding of the function of IP3 in cotton fiber elongation and highlights the possibility of cultivating better cotton varieties by manipulating GhPIPLC2D in the future. GhPIPLC2D positively regulates cotton fiber elongation GhPIPLC2D cleaves PIP2 into IP3, which could be phosphorylated to IP6 IP6 enhances fiber elongation via improving ethylene biosynthesis
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Affiliation(s)
- Liping Zhu
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Lingling Dou
- School of Chemistry and Chemical Engineering, Xianyang Normal University, Xianyang 712000, China
| | - Haihong Shang
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450000, China
| | - Hongbin Li
- College of Life Sciences, Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, Shihezi University, Shihezi 832003, China
| | - Jianing Yu
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Guanghui Xiao
- College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
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Salo VT, Li S, Vihinen H, Hölttä-Vuori M, Szkalisity A, Horvath P, Belevich I, Peränen J, Thiele C, Somerharju P, Zhao H, Santinho A, Thiam AR, Jokitalo E, Ikonen E. Seipin Facilitates Triglyceride Flow to Lipid Droplet and Counteracts Droplet Ripening via Endoplasmic Reticulum Contact. Dev Cell 2019; 50:478-493.e9. [PMID: 31178403 DOI: 10.1016/j.devcel.2019.05.016] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/27/2019] [Accepted: 05/03/2019] [Indexed: 01/02/2023]
Abstract
Seipin is an oligomeric integral endoplasmic reticulum (ER) protein involved in lipid droplet (LD) biogenesis. To study the role of seipin in LD formation, we relocalized it to the nuclear envelope and found that LDs formed at these new seipin-defined sites. The sites were characterized by uniform seipin-mediated ER-LD necks. At low seipin content, LDs only grew at seipin sites, and tiny, growth-incompetent LDs appeared in a Rab18-dependent manner. When seipin was removed from ER-LD contacts within 1 h, no lipid metabolic defects were observed, but LDs became heterogeneous in size. Studies in seipin-ablated cells and model membranes revealed that this heterogeneity arises via a biophysical ripening process, with triglycerides partitioning from smaller to larger LDs through droplet-bilayer contacts. These results suggest that seipin supports the formation of structurally uniform ER-LD contacts and facilitates the delivery of triglycerides from ER to LDs. This counteracts ripening-induced shrinkage of small LDs.
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Affiliation(s)
- Veijo T Salo
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Shiqian Li
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Helena Vihinen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Maarit Hölttä-Vuori
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | | | | | - Ilya Belevich
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Johan Peränen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | | | - Pentti Somerharju
- Department of Biochemistry, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hongxia Zhao
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Alexandre Santinho
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Universite de Paris, Paris, France
| | - Abdou Rachid Thiam
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Universite de Paris, Paris, France.
| | - Eija Jokitalo
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.
| | - Elina Ikonen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Minerva Foundation Institute for Medical Research, Helsinki, Finland.
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