Myers Zachary A, Wootan Clair M, Liang Zhikai, Zhou Peng, Engelhorn Julia, Hartwig Thomas, Nathan Springer M
Department of Plant and Microbial Biology University of Minnesota Minneapolis MN USA.
Chinese Academy of Agricultural Sciences Institute of Crop Sciences Beijing China.
Plant Direct. 2023 Apr 27;7(4):e489. doi: 10.1002/pld3.489. eCollection 2023 Apr.
The Heat Shock Factor (HSF) transcription factor family is a central and required component of plant heat stress responses and acquired thermotolerance. The HSF family has dramatically expanded in plant lineages, often including a repertoire of 20 or more genes. Here we assess and compare the composition, heat responsiveness, and chromatin profiles of the HSF families in maize and (), two model C4 panicoid grasses. Both species encode a similar number of HSFs, and examples of both conserved and variable expression responses to a heat stress event were observed between the two species. Chromatin accessibility and genome-wide DNA-binding profiles were generated to assess the chromatin of HSF family members with distinct responses to heat stress. We observed significant variability for both chromatin accessibility and promoter occupancy within similarly regulated sets of HSFs between and maize, as well as between syntenic pairs of maize HSFs retained following its most recent genome duplication event. Additionally, we observed the widespread presence of TF binding at HSF promoters in control conditions, even at HSFs that are only expressed in response to heat stress. TF-binding peaks were typically near putative HSF-binding sites in HSFs upregulated in response to heat stress, but not in stable or not expressed HSFs. These observations collectively support a complex scenario of expansion and subfunctionalization within this transcription factor family and suggest that within-family HSF transcriptional regulation is a conserved, defining feature of the family.
热激因子（HSF）转录因子家族是植物热应激反应和获得性耐热性的核心且必需的组成部分。HSF家族在植物谱系中显著扩张，通常包含20个或更多基因。在此，我们评估并比较了玉米和（）这两种C4类黍族模式禾本科植物中HSF家族的组成、热响应性和染色质图谱。两个物种编码的HSF数量相似，并且在两个物种之间观察到了对热应激事件的保守和可变表达响应的例子。生成了染色质可及性和全基因组DNA结合图谱，以评估对热应激有不同反应的HSF家族成员的染色质。我们观察到，在和玉米之间以及在最近一次基因组复制事件后保留的玉米HSF的同线对之间，在类似调控的HSF组内，染色质可及性和启动子占据情况都存在显著差异。此外，我们观察到在对照条件下，TF结合在HSF启动子上广泛存在，即使在仅对热应激有表达的HSF中也是如此。TF结合峰通常在对热应激上调的HSF中假定的HSF结合位点附近，但在稳定或不表达的HSF中则不然。这些观察结果共同支持了该转录因子家族内扩张和亚功能化的复杂情况，并表明家族内HSF转录调控是该家族保守的、决定性的特征。
