Permeability of peach leaf cuticles to boron

Abstract

Isolated leaf cuticles and intact plants of one‐year‐old potted ‘Red Haven’ trees grown in the greenhouse were used to study the permeability of leaf cuticles to boron (B). The isolated leaf cuticles were prepared enzymatically. Flux was determined using a transport cell. Permeability coefficient (P) was calculated and used as the parameter of cuticle permeability to B. For intact plant studies, enriched‐¹⁰B boric acid solution was evenly spread onto the abaxial or the adaxial side of a leaf. The trees were sacrificed three days after the treatment and selected plant parts were analyzed with ICP‐AES and ICP‐MS spectrometers. The ¹⁰B content was used as the parameter of B permeability in vivo. The permeability coefficient of peach leaf adaxial cuticle was in the order of 10^‐7 cm/sec. There were no difference in the permeability coefficients among B concentration and surtactant treatments. The pH had variable effect on B absorption through the cuticle of the adaxial side of the leaf. For the in vivo study of B uptake by peach leaves, the abaxial side was more efficient than the adaxial side, with the total ¹⁰B taken up four times greater in the abaxial side than the adaxial side. The absorption percentages of the total ¹⁰B applied in the abaxial and adaxial sides were 0.31% and 0.08%, respectively. Scratches on the treated leaves made the total ¹⁰B uptake and translocation higher than the control treatment.

Notes

Presently at Fengshan Tropical Horticultural Experiment Station, Fengshan, Kaohsiung, Taiwan 83017, R. O. C.