Tritiated water (HTO) uptake and loss in maize plant after short-term exposure of atmospheric HTO vapor at daytime and nighttime

HuiFang Shen; Feng Guo

doi:10.1016/j.apradiso.2019.108905

Tritiated water (HTO) uptake and loss in maize plant after short-term exposure of atmospheric HTO vapor at daytime and nighttime

Appl Radiat Isot. 2019 Dec:154:108905. doi: 10.1016/j.apradiso.2019.108905. Epub 2019 Sep 25.

Authors

HuiFang Shen¹, Feng Guo²

Affiliations

¹ College of Arts and Sciences, Shanxi Agricultural University, Taigu, 030801, China. Electronic address: shenhuifang@sxau.edu.cn.
² College of Resources and Environment, Shanxi Agricultural University, Taigu, 030801, China.

PMID: 31581057
DOI: 10.1016/j.apradiso.2019.108905

Abstract

Maize plants were exposed to atmospheric tritiated water (HTO) in the field for 1 h during the day and night under different growth periods. The uptake of HTO vapor by leaves and tissue free water tritium (TFWT) loss in maize plants were investigated. Rate constants of uptake of HTO from the atmosphere by maize leaves were 0.10 ± 0.02-0.21 ± 0.01 h^-1 during the daytime exposure and 0.035 ± 0.001-0.13 ± 0.01 h^-1 in the nighttime exposure. The uptake rate tended to decrease as the exposure increased and harvest neared. At the end of exposure, the TFWT concentration was highest in the leaf and lowest in the ear, the TFWT concentration in different parts of maize varied by a factor of 3-28 for daytime release and 2-30 for nighttime release. After the end of every exposure, TFWT was lost rapidly from different maize tissues for one day and then at a much slower rate until to harvest. At harvest, the TFWT concentrations varied with different maize tissues by factors of 1-4. The decrease was by factors of 4-351 for daytime exposure and 6-605 for nighttime exposure. The reduction of TFWT varied with the exposure time by the factors of 1-10 depending on plant parts. The reduction factor was lowest in kernel. This result suggests that the HTO vapor uptake rates in maize leaves and TFWT loss rates in the ear may be lower than those in C₃ plants.

Keywords: Loss; Maize; Tritiated water vapor; Uptake.