对羟基苯甲酸对烟草根系生理特性与钾素吸收的影响

探明烟草对对羟基苯甲酸的敏感性,为选择适宜栽培烟草品种提供参考,以烟草K326和红花大金元(简称红大)为材料,采用单因素试验,研究水培条件下不同浓度(0 mg/L、5mg/L、15mg/L和45mg/L)酚类物质对羟基苯甲酸对烟草根系生长、生理及根系钾素吸收的影响。结果表明:对羟基苯甲酸可抑制烟草根系生长且降低其生理活性,抑制根系对钾素的吸收及其相关基因的表达,作用效果随对羟基苯甲酸浓度增大而增强;K326对对羟基苯甲酸的敏感性高于红大。其中,5mg/L、15mg/L和45mg/L对羟基苯甲酸能抑制K326和红大根系伸长;45mg/L处理能显著降低K326根系鲜重,对红大作用不显著;不同浓度对羟基苯甲酸对根系干重均无显著作用;45 mg/L处理能显著降低根系含水率;不同浓度处理均能降低K326根系的吸收面积、活跃吸收面积、根系活力和阳离子交换量,而45mg/L处理能显著降低红大根系的活跃吸收面积;45mg/L处理能显著降低K326和红大的钾含量和积累量,K326的降幅大于红大;不同处理均能降低钾转运体蛋白基因NtTPK1、HAK1及钾离子通道蛋白基因NtKC1、TORK1的相对表达量。

Effects of PHBA (p-hydroxybenzoic acid) on Root Physiological Characteristics and Potassium Absorption of Tobacco

To explore the sensibility of tobacco to PHBA (p-hydroxybenzoic acid),and provide references for selecting the optimal tobacco variety,taking tobacco varieties K326 and Honghuadajinyuan (Hongda) as the materials,a single-factor water culture experiment was conducted to explore the effects of PHBA(0 mg/L,5 mg/L,15 mg/L,45 mg/L) on tobacco root growth,physiology and potassium absorption.Results:PHBA could inhibit tobacco root growth and decrease the physiological activity,and also inhibit potassium absorption of tobacco root and the expression of related genes,the effects of which increased with PHBA concentration;The sensitivity to PHBA of K326 was higher than Hongda.Compared with CK,PHBA with the concentrations of 5 mg/L,15 mg/L and 45 mg/L could inhibit root elongation of K326 and Hongda;45 mg/L PHBA could significantly decrease root fresh weight of K326,which had no significant influence on Hongda;PHBA had no significant influence on root dry weight;45 mg/L PHBA could significantly decrease root moisture content;PHBA could decrease root absorption area,active absorption area,root activity and cation exchange capacity of K326 effects on root absorption area of Hongda,and 45 mg/L PHBA could significantly decrease root active;45 mg/L PHBA could significantly decrease potassium content and accumulation of K326 and Hongda,the decreasing range of K326 was higher than Hongda;PHBA could decrease the relative expression of NtTPK1,HAK,NtKC1 and TORK1.