Phosphorus Uptake and Growth of Wild-Type Barley and Its Root-Hairless Mutant Cultured in Buffered-and Non-Buffered-P Solutions

Agronomy

Yucong Xie¹  Bala Rathinasabapathi¹  Guodong Liu¹  Rao Mylavarapu²  Bruce Schaffer³ 

[1] Horticultural Sciences Department, University of Florida, 1253 Fifield Hall, Gainesville, FL 32611, USA;Soil and Water Sciences Department, University of Florida, 2181 McCarty Hall, Gainesville, FL 32611, USA;Tropical Research and Education Center, University of Florida, 18905 S.W. 280th Street, Homestead, FL 33031, USA;

关键词: Hordeum vulgare L.;    split-root system;    P uptake;    root hair length and density;    buffered-P hydroponics;   

DOI  :  10.3390/agronomy10101556

来源: DOAJ

【 摘 要 】

Root hairs play an important role in phosphorus (P) nutrition of plants. To better understand the relationship between root hairs and P acquisition efficiency (PAE) in barley, experiments were conducted with the wild-type barley (cv. ’Pallas’) and its root-hairless mutant (brb). A hydroponic split-root system was used to supply P as Ca₃(PO₄)₂ (tri-calcium phosphate, TCP) to one-half and other nutrients to the other half of the root system. Using TCP as a sole P source can simulate a soil solution with buffered low P concentration in hydroponics to induce prolific root hair growth. Root morphology, plant growth, and P uptake efficiency were measured with 50 mg L⁻¹ TCP supplied to the roots in the split-root system and 0, 35, or 1000 μM NaH₂PO₄ in a non-split-root hydroponic system. The wild-type plants developed root hairs, but they did not contribute to the significant genotypic differences in the P uptake rate when a soluble P source was supplied in the non-split root system, indicating that root hair formation does not contribute to P uptake in a non-split root solution. On the other hand, when grown in a split-root system with one-half of the roots supplied with TCP, the wild-type showed 1.25-fold greater P uptake than the root hairless mutant. This study provides evidence that root hairs play an essential role in plant P uptake when P bioavailability is limited in the root zone.

【 授权许可】

Unknown