A novel fluorescent pH probe for expression in plants.
BACKGROUND
The pH is an important parameter controlling many metabolic and signalling pathways in living cells. Recombinant fluorescent pH indicators (pHluorins) have come into vogue for monitoring cellular pH. They are derived from the most popular Aequorea victoria GFP (Av-GFP). Here, we present a novel fluorescent pH reporter protein from the orange seapen Ptilosarcus gurneyi (Pt-GFP) and compare its properties with pHluorins for expression and use in plants.


RESULTS
pHluorins have a higher pH-sensitivity. However, Pt-GFP has a broader pH-responsiveness, an excellent dynamic ratio range and a better acid stability. We demonstrate how Pt-GFP expressing Arabidopsis thaliana report cytosolic pH-clamp and changes of cytosolic pH in the response to anoxia and salt-stress.


CONCLUSIONS
Pt-GFP appears to be the better choice when used for in vivo-recording of cellular pH in plants.
Schulte
Alexander
A
Zentrum für Biochemie und Molekularbiologie, Universität Kiel, Am Botanischen Garten 9, 24118 Kiel, Germany. cplieth@zbm.uni-kiel.de.
Lorenzen
Inken
I
Böttcher
Markus
M
Plieth
Christoph
C