茶树根系跨膜主动吸收氟的表观特征

王玉梅; 柴如山; 郜红建

文章摘要

王玉梅,柴如山,郜红建.茶树根系跨膜主动吸收氟的表观特征[J].农业环境科学学报,2016,35(8):1473-1479.

茶树根系跨膜主动吸收氟的表观特征

Apparent characteristics of active transmembrane uptake of fluoride by tea plant roots

投稿时间：2016-01-20

DOI：10.11654/jaes.2016-0094

中文关键词: 茶树氟低温代谢抑制剂主动吸收

英文关键词: tea plant fluoride low temperature metabolic inhibitor active uptake

基金项目:国家自然科学基金项目（41071158，31272254）；安徽省杰出青年科学基金（1408085J01）

作者	单位	E-mail
王玉梅	安徽农业大学资源与环境学院, 合肥 230036
柴如山	安徽农业大学资源与环境学院, 合肥 230036
郜红建	安徽农业大学资源与环境学院, 合肥 230036	hjgao@ahau.edu.cn

摘要点击次数: 1943

全文下载次数: 2032

中文摘要:

为研究茶树根系跨膜主动吸收氟的过程，采用溶液培养法分析了茶树吸收氟的动力学特性，探究了温度、代谢抑制剂和氯离子等因素对茶树根系主动吸收氟的影响。结果表明，浓度吸收试验可用Michaelis-Menten动力学模型拟合，获得动力学参数V_max=13.9 μg·h^-1·g^-1（根干重,DW），K_m=0.59 mmol·L^-1。与在25℃培养条件下相比，低温处理（4℃）明显抑制了茶树对氟的吸收，抑制率达到49.75%。代谢抑制剂2,4-Dinitrophenol（2,4-DNP）、叠氮钠（NaN₃）和正钒酸钠（Na₃VO₄）均抑制了茶树根系对氟的吸收过程，而且随着代谢抑制剂处理浓度的增加，茶树根系氟含量和累积量也随之不断减少。在2,4-DNP、叠氮钠和正钒酸钠浓度分别为2、0.2 mmol·L^-1和0.6 mmol·L^-1条件下，茶树根系氟含量分别比对照减少了16.1%、39.1%和20.6%。当营养液中氟和氯浓度均为5 mmol·L^-1时，氯离子显著抑制了茶树对氟的吸收，抑制率达到73.1%，存在拮抗作用。从表观上分析，茶树根系对氟的吸收是一个与跨质膜电化学势梯度、代谢能量和载体蛋白有关的主动运输过程。

英文摘要:

Active fluoride(F) uptake by tea plant roots determines the accumulation of fluoride in tea leaves. Here a solution culture experiment was conducted to examine the characteristics of active transmembrane uptake kinetics of fluoride by tea plant roots through plasma membrane and to investigate the influences of low temperature, metabolic inhibitors and chloride on fluoride absorption. Results indicated that concentration-dependent F uptake in tea plant roots was characterized by a saturation curve that was fitted by the Michaelis-Menten model. The V_max and K_m values were 13.9 μg·h^-1·g^-1 root dry weight and 0.59 mmol·L^-1, respectively. Compared with 25℃, F accumulation in tea plant roots was decreased by 49.8% at 4℃. Metabolic inhibitors, such as 2,4-DNP, NaN₃, and Na₃VO₄, significantly decreased the concentrations and content of F in tea plant roots in a concentration-effect manner. The amount of F in tea plant roots reduced by 16.1%, 39.1% and 20.6% by 2 mmol·L^-1 2,4-DNP, 0.2 mmol·L^-1 NaN₃ and 0.6 mmol·L^-1 Na₃VO₄, respectively. At 5 mmol·L^-1, chloride also significantly inhibited F absorption in tea plant roots, with 73.1% of inhibition. In summary, the uptake of F by tea plant roots is an active process that is related to the electrochemical potential gradient across the plasma membrane, metabolizable energy and carrier proteins.

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