National Engineering Research Center for Vegetables, Key Laboratory of Urban Agriculture (North China), Institute of Vegetable Sciences, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
Beijing Key Laboratory of New Technology in Agricultural Application, National Demonstration Center for Experimental Plant Production Education, Plant Science and Technology College, Beijing University of Agriculture, Beijing 102206, China.
Int J Mol Sci. 2022 Nov 4;23(21):13509. doi: 10.3390/ijms232113509.
Warm temperatures induce plant bolting accompanied by flower initiation, where endogenous auxin is dynamically associated with accelerated growth. Auxin signaling is primarily regulated by a family of plant-specific transcription factors, AUXIN RESPONSE FACTORS (ARFs), which either activate or repress the expression of downstream genes in response to developmental and environmental cues. However, the relationship between ARFs and bolting has not been completely understood in lettuce yet. Here, we identified 24 s ( ARFs) in the lettuce genome. The phylogenetic tree indicated that LsARFs could be classified into three clusters, which was well supported by the analysis of exon-intron structure, consensus motifs, and domain compositions. RNA-Seq analysis revealed that more than half of the s were ubiquitously expressed in all tissues examined, whereas a small number of LsARFs responded to UV or cadmium stresses. qRT-PCR analysis indicated that the expression of most s could be activated by more than one phytohormone, underling their key roles as integrative hubs of different phytohormone signaling pathways. Importantly, the majority of s displayed altered expression profiles under warm temperatures, implying that their functions were tightly associated with thermally accelerated bolting in lettuce. Importantly, we demonstrated that silencing of expression of which was significantly increased by elevated temperatures, resulted in delayed bolting under warm temperatures, suggesting that might conduce to the thermally induced bolting. Together, our results provide molecular insights into the gene family in lettuce, which will facilitate the genetic improvement of the lettuce in an era of global warming.
温暖的温度诱导植物抽薹伴随着花的起始，其中内源生长素与加速生长动态相关。生长素信号主要受植物特异性转录因子 AUXIN RESPONSE FACTORS (ARFs)家族调节，该家族响应发育和环境线索，激活或抑制下游基因的表达。然而，ARFs 与抽薹之间的关系在生菜中尚未完全理解。在这里，我们在生菜基因组中鉴定了 24 个 s (ARFs)。系统发育树表明，LsARFs 可以分为三个簇，这得到了外显子-内含子结构、一致基序和结构域组成分析的很好支持。RNA-Seq 分析表明，超过一半的 s 在所有检查的组织中普遍表达，而少数 LsARFs 对 UV 或镉胁迫有反应。qRT-PCR 分析表明，大多数 s 的表达可以被一种以上的植物激素激活，这表明它们作为不同植物激素信号通路的整合枢纽发挥着关键作用。重要的是，大多数 s 在温暖的温度下表现出改变的表达谱，这表明它们的功能与生菜中受温度加速的抽薹密切相关。重要的是，我们证明了在温暖的温度下，表达的沉默显著增加，导致抽薹延迟，这表明可能有助于温度诱导的抽薹。总之，我们的研究结果为生菜中的 基因家族提供了分子见解，这将有助于在全球变暖的时代对生菜进行遗传改良。
