人参幼根对苯甲酸胁迫的形态学响应及基因差异表达

Morphological Response of Ginseng Root to Benzoic Acid and Differential Genes Expression Analysis

目的:研究苯甲酸胁迫对人参幼根生长、根尖细胞显微结构、超微结构以及功能基因表达的影响。方法:采用体视显微镜观察人参幼根根尖形态结构;采用光学显微镜观察人参幼根显微结构;采用透射电镜研究苯甲酸对人参根尖超微结构的影响;采用qRT-PCR方法研究功能基因差异表达情况。结果:苯甲酸能够抑制人参根尖根毛的生长,根尖表皮组织排列疏松,并导致细胞内含物出现异常,细胞壁增厚;核仁核膜解体、消失;细胞内淀粉颗粒空泡化,逐渐解体消失。另外,苯甲酸胁迫还导致1个ARF-GEF,1个b HLH,2个XTH,1个MYB,1个ZAT和1个s HSP基因的差异表达。结论 :苯甲酸胁迫对人参根尖细胞结构及功能基因表达均有影响。

Objective：To study the influence of benzoic acid stress on root growth，micro- and ultra-structures of root tip cells，expression of functional genes of Panax ginseng.Methods：The root morphological structure of ginseng root tips was observed by stereomicroscope.The microstructure of root was observed by traditional optical microscope.The influence of benzoic acid on the ultrastructure of root tip of P.ginseng was observed by transmission electron microscope.The expression of differentially expressed genes was analyzed by RT-PCR.Results：The growth of fibril on the root tips was inhibited by benzoic acid，and resulted in the loosely arrangement of apical epidermal tissue.The cell contents was abnormally changed，the cell wall was thicken，the nuclear membrane and nucleolus disappeared，starch grains were of vacuolation and even disappeared.Furthermore，benzoic acid stress also resulted in the differential expression of ARF-GEF，bHLH，XTH，MYB，ZAT and sHSP genes.Conclusion：Benzoic acid stress has significant influences on the structure of root tip cells and the expression of functional genes of P.ginseng.