Cao Zhengyan, Wu Peiyin, Gao Hongmei, Xia Ning, Jiang Ying, Tang Ning, Liu Guohua, Chen Zexiong
College of Landscape Architecture and Life Science, Chongqing University of Arts and Sciences, Chongqing, 402160, China.
College of Horticulture and Gardening, Yangtze University, Jingzhou, 434025, China.
Genes Genomics. 2022 Feb;44(2):219-235. doi: 10.1007/s13258-021-01118-8. Epub 2021 Jun 10.
Lonicera macranthoides is an important woody plant with high medicinal values widely cultivated in southern China. WRKY, one of the largest transcription factor families, participates in plant development, senescence, and stress responses. However, a comprehensive study of the WRKY family in L. macranthoides hasn't been reported previously.
To establish an extensive overview of the WRKY family in L. macranthoides and identify senescence-responsive members of LmWRKYs.
RNA-Seq and phylogenetic analysis were employed to identify the LmWRKYs and their evolutionary relationships. Quantitative real-time (qRT-PCR) and transgenic technology was utilized to investigate the roles of LmWRKYs in response to developmental-, cold-, and ethylene-induced senescence.
A total of 61 LmWRKY genes with a highly conserved motif WRKYGQK were identified. Phylogenetic analysis of LmWRKYs together with their orthologs from Arabidopsis classified them into three groups, with the number of 15, 39, and 7, respectively. 17 LmWRKYs were identified to be differentially expressed between young and aging leaves by RNA-Seq. Further qRT-PCR analysis showed 15 and 5 LmWRKY genes were significantly induced responding to tissue senescence in leaves and stems, respectively. What's more, five LmWRKYs, including LmWRKY4, LmWRKY5, LmWRKY6, LmWRKY11, and LmWRKY16 were dramatically upregulated under cold and ethylene treatment in both leaves and stems, indicating their involvements commonly in developmental- and stress-induced senescence. In addition, function analysis revealed LmWRKY16, a homolog of AtWRKY75, can accelerate plant senescence, as evidenced by leaf yellowing during reproductive growth in LmWRKY16-overexpressing tobaccos.
The results lay the foundation for molecular characterization of LmWRKYs in plant senescence.
大花忍冬是一种重要的木本植物，具有很高的药用价值，在中国南方广泛种植。WRKY是最大的转录因子家族之一，参与植物的发育、衰老和应激反应。然而，此前尚未有对大花忍冬中WRKY家族的全面研究报道。
全面了解大花忍冬中WRKY家族的情况，并鉴定对衰老有响应的大花忍冬WRKY（LmWRKY）成员。
采用RNA测序和系统发育分析来鉴定LmWRKY基因及其进化关系。利用定量实时（qRT-PCR）和转基因技术研究LmWRKY基因在响应发育、低温和乙烯诱导的衰老过程中的作用。
共鉴定出61个具有高度保守基序WRKYGQK的LmWRKY基因。对LmWRKY基因及其来自拟南芥的直系同源基因进行系统发育分析，将它们分为三组，分别有15个、39个和7个。通过RNA测序鉴定出17个LmWRKY基因在幼叶和衰老叶片之间差异表达。进一步的qRT-PCR分析表明，分别有15个和5个LmWRKY基因在叶片和茎中对组织衰老有显著诱导响应。此外，包括LmWRKY4、LmWRKY5、LmWRKY6、LmWRKY11和LmWRKY16在内的5个LmWRKY基因在叶片和茎的低温及乙烯处理下显著上调，表明它们共同参与发育和应激诱导的衰老过程。此外，功能分析表明，AtWRKY75的同源基因LmWRKY16可加速植物衰老，过表达LmWRKY16的烟草在生殖生长期间叶片变黄证明了这一点。
这些结果为LmWRKY基因在植物衰老中的分子特征研究奠定了基础。
