香菇转录因子LeZNF143响应高温胁迫的功能分析

Functional analysis of transcription factor LeZNF143 participating in heat stress responses in Lentinula edodes

高温胁迫是影响香菇生长发育的非生物胁迫之一,转录因子在调节香菇对高温胁迫的防御反应中起着至关重要的作用。本研究测定了15个香菇品种高温胁迫后菌丝恢复生长的速度,从中筛选出了高温耐受型菌株NKY-5和敏感型菌株NKY-11。定量结果显示,C2H2型转录因子LeZNF143在菌丝体中高表达,高温胁迫下,菌株NKY-5中LeZNF143基因诱导表达显著高于NKY-11;亚细胞定位显示LeZNF143定位在细胞核中;将香菇转录因子LeZNF143在酵母中过表达,显著提高了酵母对高温胁迫的耐受性,推测转录因子LeZNF143参与调控香菇响应高温胁迫。通过JASPAR数据库预测LeZNF143的下游靶基因为漆酶基因(Lcc4/Lcc7/Lcc11),高温胁迫下,香菇体内漆酶活性显著增高,耐受型菌株NKY-5的漆酶活性显著高于敏感型菌株NKY-11。综上所述,转录因子LeZNF143可能通过调控下游漆酶的活性提高香菇对热胁迫介导的氧化应激的耐受性。

Heat stress is one of the abiotic stresses that affect the growth and development of Lentinula edodes.Transcription factor was a crucial regulator for defense against heat stress in L.edodes.Fifteen strains of L.edodes were selected for determination of the mycelial growth rate after heat stress,and the high temperature-tolerant strain NKY-5 and the temperature-susceptible strain NKY-11 were screened.RT-qPCR test indicated that the C2H2 transcription factor LeZNF143 exhibited predominant expression in mycelium and the gene expression of the LeZNF143 in NKY-5 was significantly higher than that in NKY-11 under heat stress treatment.It was found that LeZNF143 localized in the nucleus.The overexpression of LeZNF143 in yeast resulted in a significant enhancement of yeast’s tolerance to high temperature.These findings speculated that the LeZNF143 participated in response to heat stress in L.edodes.Prediction through JASPAR database indicated that the laccase genes(Lcc4/Lcc7/Lcc11)were the downstream target of LeZNF143.The laccase activity assay exhibited that high temperatureinduced enzyme activity significantly increased both in NKY-5 and NKY-11 strains,and the tolerant strain NKY-5 displayed notably higher laccase activity than the sensitive strain NKY-11 in L.edodes.The conclusion of our study was that the transcription factor LeZNF143 potentially enhanced the mycelial tolerance to the oxidative stress caused by heat stress through modulating the activity of laccase in L.edodes.