Abstract
White lupin (Lupinus albus) is a legume that is very efficient in accessing unavailable phosphorus (Pi). It develops short, densely clustered tertiary lateral roots (cluster/proteoid roots) in response to Pi limitation. In this report, we characterize two glycerophosphodiester phosphodiesterase (GPX-PDE) genes (GPX-PDE1 and GPX-PDE2) from white lupin and propose a role for these two GPX-PDEs in root hair growth and development and in a Pi stress-induced phospholipid degradation pathway in cluster roots. Both GPX-PDE1 and GPX-PDE2 are highly expressed in Pi-deficient cluster roots, particularly in root hairs, epidermal cells, and vascular bundles. Expression of both genes is a function of both Pi availability and photosynthate. GPXPDE1 Pi deficiency-induced expression is attenuated as photosynthate is deprived, while that of GPX-PDE2 is strikingly enhanced. Yeast complementation assays and in vitro enzyme assays revealed that GPX-PDE1 shows catalytic activity with glycerophosphocholine while GPX-PDE2 shows highest activity with glycerophosphoinositol. Cell-free protein extracts from Pi-deficient cluster roots display GPX-PDE enzyme activity for both glycerophosphocholine and glycerophosphoinositol. Knockdown of expression of GPX-PDE through RNA interference resulted in impaired root hair development and density. We propose that white lupin GPX-PDE1 and GPX-PDE2 are involved in the acclimation to Pi limitation by enhancing glycerophosphodiester degradation and mediating root hair development.
Original language | English (US) |
---|---|
Pages (from-to) | 1131-1148 |
Number of pages | 18 |
Journal | Plant physiology |
Volume | 156 |
Issue number | 3 |
DOIs | |
State | Published - Jul 2011 |
Fingerprint
Dive into the research topics of 'White lupin cluster root acclimation to phosphorus deficiency and root hair development involve unique glycerophosphodiester phosphodiesterases'. Together they form a unique fingerprint.Equipment
-
-
-
University Imaging Centers
Mark A Sanders (Program Director) & Guillermo Marques (Scientific Director)
University Imaging CentersEquipment/facility: Facility