【目的】观测高渗胁迫对玉米大斑病菌(Setosphaeria turcica)生长发育的影响,探讨甘油是否为病菌细胞中的渗透调节物质,分析STKI在高渗胁迫下的表达规律。【方法】采用2种高渗胁迫条件处理玉米大斑病菌,分析高渗胁迫对病菌生长发育的影响;检测高渗胁迫下菌丝细胞中甘油含量的变化,明确甘油是否为病菌中的渗透调节物质;利用半定量RT-PCR方法,分析高渗胁迫条件下STKI表达规律。【结果】玉米大斑病菌菌丝细胞的等渗液浓度为0.78mol·L^-1;在高渗胁迫条件下,菌落颜色均发生显著变化。1mol·L^-1 NaCl处理后菌落呈红褐色,菌落的生长速率也受到到明显的抑制;在1mol·L^-1 NaCl胁迫下菌丝细胞中原生质体浓缩,出现明显的浓缩颗粒;随胁迫时间的延长和渗透胁迫物质浓度的增加,细胞中甘油含量显著增加;STKI在高渗胁迫48h内表达量稳定增加。【结论】高渗胁迫抑制玉米大斑病菌菌落生长,改变菌落颜色,使菌丝细胞中原生质体高度浓缩,部分菌丝膨大呈球状;甘油是病菌细胞中的一种渗透调节物质;STKI参与调控病菌的渗透胁迫反应。
[Objective] The objective of this study is to measure the effect of hyperosmotic stress on the growth and development of Setosphaeria turcica, to analyze whether or not the glycerol is one of the compatible solutes, and to detect the expression characteristic of STK1 when the pathogen is cultured under hyperosmotic stress. [Method] The growth and development orS. turcica, which cultured under 2 different hyperosmotic stresses, were observed. By analyzing the change of glycerol content in mycelium cells, it was confirmed that glycerol was one of the compatible solutes. The expression characteristic of STK1 was detected using semiquantitative RT-PCR method. [Result] Isotonic solution concentration ofhyphal cells ofS. turcica was 0.78 mol-L^-1. The colony color changed distinctly under hyperosmotic stress. The colony cultured on PDA medium containing 1 mol·L^-1 NaCl was reddish-brown in colour, the growth rate of the colony was repressed remarkably, cultured on PDA medium containing 1 mol·L^-1 NaCl showed strong inhibition. The condensation was observed in the protoplasts when cultured in 1 mol.L1 NaC1 treatment. With the increase of hyperosmotic stress time and compatible solute concentration, glycerol content increased evidently. The expression level of STK1 enhanced distinctly within 48 hours under hyperosmotic stress. [ Conclusion ] Colony growth rate was inhibited, colony color turned obviously, protoplast became concentrated, some mycelium cells enlarged and changed into globosed under hyperosmotic stress in S. turcica. Glycerol was one of the compatible solutes in the mycelium cells of S. turcica. STK1 took part in regulating hyperosmotic stress responses in S. turcica.