Details

Autor(en) / Beteiligte

• Chenge‐Espinosa, Marel
• Cordoba, Elizabeth
• Romero‐Guido, Cynthia
• Toledo‐Ortiz, Gabriela
• León, Patricia

Titel

Shedding light on the methylerythritol phosphate (MEP)‐pathway: long hypocotyl 5 (HY5)/phytochrome‐interacting factors (PIFs) transcription factors modulating key limiting steps

Ist Teil von

• The Plant journal : for cell and molecular biology, 2018-11, Vol.96 (4), p.828-841

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2018

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Summary The plastidial methylerythritol phosphate (MEP) pathway is an essential route for plants as the source of precursors for all plastidial isoprenoids, many of which are of medical and biotechnological importance. The MEP pathway is highly sensitive to environmental cues as many of these compounds are linked to photosynthesis and growth and light is one of the main regulatory factors. However, the mechanisms coordinating the MEP pathway with light cues are not fully understood. Here we demonstrate that by a differential direct transcriptional modulation, via the key‐master integrators of light signal transduction HY5 and PIFs which target the genes that encode the rate‐controlling DXS1, DXR and HDR enzymes, light imposes a direct, rapid and potentially multi‐faceted response that leads to unique protein dynamics of this pathway, resulting in a significant difference in the protein levels. For DXS1, PIF1/HY5 act as a direct activation/suppression module. In contrast, DXR accumulation in response to light results from HY5 induction with minor contribution of de‐repression by PIF1. Finally, HDR transcription increases in the light exclusively by suppression of the PIFs repression. This is an example of how light signaling components can differentially multi‐target the initial steps of a pathway whose products branch downstream to all chloroplastic isoprenoids. These findings demonstrate the diversity and flexibility of light signaling components that optimize key biochemical pathways essential for plant growth. Significance Statement Light imposes a direct, rapid and potentially multi‐faceted effect that leads to unique protein dynamics to the main flux‐limiting steps of the MEP pathway, a key route essential for plants. Through differential direct transcriptional interaction, the key‐master integrators of light signals HY5 and PIFs, target the main flux‐limiting steps of the pathway. Our work illustrates how light signals can impose contrasting dynamics over a key pathway whose products multi‐branch downstream to all chloroplastic isoprenoids.