Functional analysis of phospholipase Dδ family in tobacco pollen tubes

0532422 - ÚEB 2021 RIV GB eng J - Journal Article
Pejchar, Přemysl - Sekereš, Juraj - Novotný, Ondřej - Žárský, Viktor - Potocký, Martin
Functional analysis of phospholipase Dδ family in tobacco pollen tubes.
Plant Journal. Roč. 103, č. 1 (2020), s. 212-226. ISSN 0960-7412. E-ISSN 1365-313X
R&D Projects: GA ČR GA17-27477S; GA ČR(CZ) GA19-21758S; GA MŠMT(CZ) EF16_019/0000738; GA MŠMT(CZ) LM2015062
Institutional support: RVO:61389030
Keywords : membrane trafficking * Nicotiana tabacum * phosphatidic acid * phospholipase D * pollen tube * tip growth * tobacco
OECD category: Cell biology
Impact factor: 6.486, year: 2020
Method of publishing: Open access
http://doi.org/10.1111/tpj.14720

Phosphatidic acid (PA), an important signalling and metabolic phospholipid, is predominantly localized in the subapical plasma membrane (PM) of growing pollen tubes. PA can be produced from structural phospholipids by phospholipase D (PLD), but the isoforms responsible for production of PM PA were not identified yet and their functional roles remain unknown. Following genome-wide bioinformatic analysis of the PLD family in tobacco, we focused on the pollen-overrepresented PLDδ class. Combining live-cell imaging, gene overexpression, lipid-binding and structural bioinformatics, we characterized five NtPLDδ isoforms. Distinct PLDδ isoforms preferentially localize to the cytoplasm or subapical PM. Using fluorescence recovery after photobleaching, domain deletion and swapping analyses we show that membrane-bound PLDδs are tightly bound to PM, primarily via the central catalytic domain. Overexpression analyses suggested isoform PLDδ3 as the most important member of the PLDδ subfamily active in pollen tubes. Moreover, only PLDδ3 shows significant constitutive PLD activity in vivo and, in turn, PA promotes binding of PLDδ3 to the PM. This forms a positive feedback loop leading to PA accumulation and the formation of massive PM invaginations. Tightly controlled production of PA generated by PLDδ3 at the PM is important for maintaining the balance between various membrane trafficking processes that are crucial for plant cell tip growth.
Permanent Link: http://hdl.handle.net/11104/0310918