Limits...
A novel role for the root cap in phosphate uptake and homeostasis.

Kanno S, Arrighi JF, Chiarenza S, Bayle V, Berthomé R, Péret B, Javot H, Delannoy E, Marin E, Nakanishi TM, Thibaud MC, Nussaume L - Elife (2016)

Bottom Line: Remarkably, the diminutive size of the root cap cells at the root-to-soil exchange surface accounts for a significant amount of the total seedling phosphate uptake (approximately 20%).This level of Pi absorption is sufficient for shoot biomass production (up to a 180% gain in soil), as well as repression of Pi starvation-induced genes.These results extend our understanding of this important tissue from its previously described roles in environmental perception to novel functions in mineral nutrition and homeostasis control.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan.

ABSTRACT
The root cap has a fundamental role in sensing environmental cues as well as regulating root growth via altered meristem activity. Despite this well-established role in the control of developmental processes in roots, the root cap's function in nutrition remains obscure. Here, we uncover its role in phosphate nutrition by targeted cellular inactivation or phosphate transport complementation in Arabidopsis, using a transactivation strategy with an innovative high-resolution real-time (33)P imaging technique. Remarkably, the diminutive size of the root cap cells at the root-to-soil exchange surface accounts for a significant amount of the total seedling phosphate uptake (approximately 20%). This level of Pi absorption is sufficient for shoot biomass production (up to a 180% gain in soil), as well as repression of Pi starvation-induced genes. These results extend our understanding of this important tissue from its previously described roles in environmental perception to novel functions in mineral nutrition and homeostasis control.

No MeSH data available.


Related in: MedlinePlus

Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves. Values are means ± SD of three independent experiments. Pools of 10 to 20 plant tissues were analyzed. Significantly different from phf1-1 line: *P=0.008 (Leaves), P=0.0009 (Roots) (Student’s t-test).DOI:http://dx.doi.org/10.7554/eLife.14577.01110.7554/eLife.14577.012Figure 3—figure supplement 1—source data 1.Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves.DOI:http://dx.doi.org/10.7554/eLife.14577.012
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4829427&req=5

fig3s1: Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves. Values are means ± SD of three independent experiments. Pools of 10 to 20 plant tissues were analyzed. Significantly different from phf1-1 line: *P=0.008 (Leaves), P=0.0009 (Roots) (Student’s t-test).DOI:http://dx.doi.org/10.7554/eLife.14577.01110.7554/eLife.14577.012Figure 3—figure supplement 1—source data 1.Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves.DOI:http://dx.doi.org/10.7554/eLife.14577.012

Mentions: Reduced growth in the aerial parts is a well-known consequence of Pi starvation. This feature is conserved in the phf1-1 mutant (Gonzalez et al., 2005) even in Pi-rich medium, in agreement with the low Pi-status of these plants. By contrast, the root architectures of phf1-1 (Thibaud et al., 2010) and the WT were similar in Pi-rich medium, confirming that root growth responds to external Pi (Svistoonoff et al., 2007; Peret et al., 2011). This facilitates analyses between the phf1-1 mutant, the complemented line and the WT control at the whole plant level. Free Pi measured in roots or leaves of the complemented line was similar to the phf1-1 mutant, indicating full metabolization of the excess absorbed Pi (Figure 3—figure supplement 1, Figure 3—figure supplement 1—source data 1).


A novel role for the root cap in phosphate uptake and homeostasis.

Kanno S, Arrighi JF, Chiarenza S, Bayle V, Berthomé R, Péret B, Javot H, Delannoy E, Marin E, Nakanishi TM, Thibaud MC, Nussaume L - Elife (2016)

Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves. Values are means ± SD of three independent experiments. Pools of 10 to 20 plant tissues were analyzed. Significantly different from phf1-1 line: *P=0.008 (Leaves), P=0.0009 (Roots) (Student’s t-test).DOI:http://dx.doi.org/10.7554/eLife.14577.01110.7554/eLife.14577.012Figure 3—figure supplement 1—source data 1.Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves.DOI:http://dx.doi.org/10.7554/eLife.14577.012
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4829427&req=5

fig3s1: Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves. Values are means ± SD of three independent experiments. Pools of 10 to 20 plant tissues were analyzed. Significantly different from phf1-1 line: *P=0.008 (Leaves), P=0.0009 (Roots) (Student’s t-test).DOI:http://dx.doi.org/10.7554/eLife.14577.01110.7554/eLife.14577.012Figure 3—figure supplement 1—source data 1.Effect of PHF1 complementation on free Pi content.Quantification of free phosphate present in roots and leaves.DOI:http://dx.doi.org/10.7554/eLife.14577.012
Mentions: Reduced growth in the aerial parts is a well-known consequence of Pi starvation. This feature is conserved in the phf1-1 mutant (Gonzalez et al., 2005) even in Pi-rich medium, in agreement with the low Pi-status of these plants. By contrast, the root architectures of phf1-1 (Thibaud et al., 2010) and the WT were similar in Pi-rich medium, confirming that root growth responds to external Pi (Svistoonoff et al., 2007; Peret et al., 2011). This facilitates analyses between the phf1-1 mutant, the complemented line and the WT control at the whole plant level. Free Pi measured in roots or leaves of the complemented line was similar to the phf1-1 mutant, indicating full metabolization of the excess absorbed Pi (Figure 3—figure supplement 1, Figure 3—figure supplement 1—source data 1).

Bottom Line: Remarkably, the diminutive size of the root cap cells at the root-to-soil exchange surface accounts for a significant amount of the total seedling phosphate uptake (approximately 20%).This level of Pi absorption is sufficient for shoot biomass production (up to a 180% gain in soil), as well as repression of Pi starvation-induced genes.These results extend our understanding of this important tissue from its previously described roles in environmental perception to novel functions in mineral nutrition and homeostasis control.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan.

ABSTRACT
The root cap has a fundamental role in sensing environmental cues as well as regulating root growth via altered meristem activity. Despite this well-established role in the control of developmental processes in roots, the root cap's function in nutrition remains obscure. Here, we uncover its role in phosphate nutrition by targeted cellular inactivation or phosphate transport complementation in Arabidopsis, using a transactivation strategy with an innovative high-resolution real-time (33)P imaging technique. Remarkably, the diminutive size of the root cap cells at the root-to-soil exchange surface accounts for a significant amount of the total seedling phosphate uptake (approximately 20%). This level of Pi absorption is sufficient for shoot biomass production (up to a 180% gain in soil), as well as repression of Pi starvation-induced genes. These results extend our understanding of this important tissue from its previously described roles in environmental perception to novel functions in mineral nutrition and homeostasis control.

No MeSH data available.


Related in: MedlinePlus