Zhang Li, Chen LiJing, Pang ShengQun, Zheng Qun, Quan ShaoWen, Liu YuFeng, Xu Tao, Liu YuDong, Qi MingFang
College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, China.
Key Laboratory of Agricultural Biotechnology of Liaoning Province, Shenyang Agricultural University, Shenyang, China.
Front Plant Sci. 2022 Mar 4;13:849048. doi: 10.3389/fpls.2022.849048. eCollection 2022.
APETALA2/ethylene responsive factors (AP2/ERF) are unique regulators in the plant kingdom and are involved in the whole life activity processes such as development, ripening, and biotic and abiotic stresses. In tomato (), there are 140 AP2/ERF genes; however, their functionality remains poorly understood. In this work, the 14th and 19th amino acid differences in the AP2 domain were used to distinguish DREB and ERF subfamily members. Even when the AP2 domain of 68 ERF proteins from 20 plant species and motifs in tomato DREB and ERF proteins were compared, the binding ability of DREB and ERF proteins with DRE/CRT and/or GCC boxes remained unknown. During fruit development and ripening, the expressions of 13 DREB and 19 ERF subfamily genes showed some regular changes, and the promoters of most genes had ARF, DRE/CRT, and/or GCC boxes. This suggests that these genes directly or indirectly respond to IAA and/or ethylene (ET) signals during fruit development and ripening. Moreover, some of these may feedback regulate IAA or ET biosynthesis. In addition, 16 EAR motif-containing ERF genes in tomato were expressed in many organs and their total transcripts per million (TPM) values exceeded those of other ERF genes in most organs. To determine whether the EAR motif in EAR motif-containing ERF proteins has repression function, their EAR motifs were retained or deleted in a yeast one-hybrid (YIH) assay. The results indicate that most of EAR motif-containing ERF proteins lost repression activity after deleting the EAR motif. Moreover, some of these were expressed during ripening. Thus, these EAR motif-containing ERF proteins play vital roles in balancing the regulatory functions of other ERF proteins by completing the DRE/CRT and/or GCC box sites of target genes to ensure normal growth and development in tomato.
APETALA2/乙烯响应因子（AP2/ERF）是植物界中独特的调控因子，参与植物整个生命活动过程，如发育、成熟以及生物和非生物胁迫响应。在番茄中，有140个AP2/ERF基因；然而，它们的功能仍知之甚少。在这项研究中，利用AP2结构域中第14和第19位氨基酸的差异来区分DREB和ERF亚家族成员。即便比较了来自20种植物的68个ERF蛋白的AP2结构域以及番茄DREB和ERF蛋白中的基序，DREB和ERF蛋白与DRE/CRT和/或GCC框的结合能力仍不清楚。在果实发育和成熟过程中，13个DREB和19个ERF亚家族基因的表达呈现出一些规律性变化，且大多数基因的启动子含有ARF、DRE/CRT和/或GCC框。这表明这些基因在果实发育和成熟过程中直接或间接响应生长素（IAA）和/或乙烯（ET）信号。此外，其中一些基因可能反馈调节IAA或ET的生物合成。另外，番茄中16个含EAR基序的ERF基因在多个器官中表达，且它们的每百万转录本总数（TPM）值在大多数器官中超过了其他ERF基因。为了确定含EAR基序的ERF蛋白中的EAR基序是否具有抑制功能，在酵母单杂交（YIH）试验中保留或删除了它们的EAR基序。结果表明，大多数含EAR基序的ERF蛋白在删除EAR基序后失去了抑制活性。而且，其中一些在成熟过程中表达。因此，这些含EAR基序的ERF蛋白通过完成靶基因的DRE/CRT和/或GCC框位点，在平衡其他ERF蛋白的调控功能中发挥着至关重要的作用，以确保番茄的正常生长和发育。
